The annual decay rate for the given radioactive substance with a half-life of 1404 years is 0.0494%.Explanation:Half-life of a radioactive substance:
The half-life of a radioactive substance is the time it takes for half of the radioactive atoms to decay. Mathematically, it is expressed as:N(t) = N₀(1/2)^(t/t½)Where,N(t) = the number of radioactive atoms present at time tN₀ = the initial number of radioactive atoms presentt = time t½ = half-life of the radioactive substanceAnnual decay rate:
The annual decay rate can be calculated using the half-life of the radioactive substance as follows:
Annual decay rate = (ln2 / t½) × 100Where,ln = the natural logarithmt½ = half-life of the radioactive substance Plugging in the values, Annual decay rate = (ln2 / 1404) × 100 = 0.0494%Therefore, the annual decay rate for the given radioactive substance with a half-life of 1404 years is 0.0494%.
To know more about radioactive refer to:
https://brainly.com/question/30692881
#SPJ11
If a pure sample of an oxide of sulfur contains 40. percent sulfur and 60. percent oxygen by mass, then the empirical formula of the oxide is: 1. SO3 2. SO4 3. S2O6 4. S2O8
The empirical formula of the oxide is SO3. The empirical formula is the simplest whole-number ratio of atoms of each element in a compound.
Let's use the method of assuming 100 g of the sample.
Therefore, the sample contains 40 g of sulfur and 60 g of oxygen by mass.
Mass of Sulfur = 40 g
Mass of Oxygen = 60 g
Next, determine the number of moles of each element present in the sample using their molar masses.
Sulfur has a molar mass of 32 g/mol.
Moles of sulfur = 40 g / 32 g/mol
= 1.25 mol
Oxygen has a molar mass of 16 g/mol.
Moles of oxygen = 60 g / 16 g/mol
= 3.75 mol
Divide the number of moles of each element by the smallest number of moles obtained in the previous step to get the simplest ratio of atoms.
Sulfur: 1.25 mol ÷ 1.25 mol = 1
Oxygen: 3.75 mol ÷ 1.25 mol = 3
Therefore, the empirical formula of the oxide is SO3, which means that the empirical formula has 1 sulfur atom and 3 oxygen atoms.
The empirical formula of the oxide is SO3.
Learn more about the empirical formula:
brainly.com/question/14044066
#SPJ11
A 20.0 mL sample of 0.150 M ethylamine is titrated with 0.050 M HCl.
What is the pH after the addition of 5.0 mL of HCl? For ethylamine, pKb= 3.25.
What is the pH after the addition of 5.0 of ? For ethylamine, = 3.25.
a) 2.96
b) 11.46
c) 11.79
d) 10.75
The pH after the addition of 5.0 mL of HCl to a 20.0 mL sample of 0.150 M ethylamine is 2.96.
What is the resulting pH after adding 5.0 mL of HCl to the ethylamine solution?To determine the pH after the addition of HCl, we need to consider the reaction between ethylamine and HCl. Ethylamine is a weak base, and HCl is a strong acid. The reaction between them will result in the formation of ammonium chloride (NH4Cl).
Ethylamine, being a weak base, will partially react with HCl, resulting in the formation of NH4Cl and the release of H+ ions. The pH is a measure of the concentration of H+ ions in a solution, so by calculating the concentration of H+ ions, we can determine the resulting pH.
The pKb value of ethylamine is given as 3.25. Using this information, we can calculate the concentration of OH- ions and convert it to H+ ion concentration to find the pH.
After performing the calculations, the resulting pH is found to be 2.96. This indicates that the addition of HCl has caused the solution to become acidic.
Learn more about pH
brainly.com/question/2288405
#SPJ11
strontium hydroxide, sr(oh)2, is a strong base that will completely dissociate into ions in water. calculate the following. (the temperature of each solution is 25°c.)
Given information Strontium hydroxide dissociates completely in water as follows: Sr(OH)₂ (s) → Sr²⁺ (aq) + 2OH⁻ (aq).
The dissociation constant for this reaction is given by the expression: Kb = [Sr²⁺][OH⁻]²/[Sr(OH)₂] Moles of Strontium Hydroxide (Sr(OH)₂) = 1 mol Concentration of Strontium Hydroxide (Sr(OH)₂) = 1 M Number of moles of OH⁻ ions produced by 1 mole of Sr(OH)₂ = 2 moles Concentration of OH⁻ ions = 2 M. The equilibrium constant (Kb) is given by: Kb = [Sr²⁺][OH⁻]²/[Sr(OH)₂] Kb = (2)²/1 = 4 pOH = 14 - pH pOH = 14 - 14 = 0pOH of the solution is 0.
The concentration of [OH⁻] can be calculated as follows: pOH = - log[OH⁻][OH⁻] = 10^(-pOH) = 10⁰ = 1 M. The concentration of OH⁻ ions is 1 M or 1 mol/L or 1 N. Note: pOH + pH = 14. If one of the values is known, the other can be calculated as shown in the above calculations.
To know more about Strontium hydroxide visit:-
https://brainly.com/question/32096733
#SPJ11
determine the osmotic pressure for this solution in equilibrium with pure water with a membrane that cannot be permeated by the polymer.
The osmotic pressure will be equal to the applied pressure that is required to prevent the flow of water from the solution to the pure water with the impermeable membrane.
Osmotic pressure is defined as the amount of pressure applied to the solution to prevent the inward flow of water through a semipermeable membrane from a high concentration of water to low concentration of water. It is the amount of pressure required to prevent the osmosis. The osmotic pressure is given by the Van’t Hoff Equation.
In equilibrium, the osmotic pressure of the solution is equal to the applied pressure. This means that the osmotic pressure and applied pressure balance each other. As the solution does not flow into the membrane, the applied pressure will have to be increased to prevent the inward flow of water. The osmotic pressure of the solution will be equal to the applied pressure.
To know more about osmotic visit:
https://brainly.com/question/30379713
#SPJ11
Identify items that can be used to control the boiling when heating liquid in a round bottom flask. Select one or more: Boiling chips or stones A stir bar and stir plate D A Bunsen burner A rubber stopper or cork
Boiling chips or stones and a rubber stopper or cork can be used to control boiling when heating liquid in a round bottom flask.Boiling chips or stones are small, insoluble pieces of material that are added to liquids when heated to provide nucleation sites for the formation of bubbles.
These chips or stones are usually made of alumina or silica gel. By providing nucleation sites, the boiling chips or stones ensure that the liquid boils evenly and prevents any superheating that may lead to violent boiling or boiling over.A rubber stopper or cork can also be used to control boiling when heating liquid in a round bottom flask. The rubber stopper or cork can be used to seal the round bottom flask, preventing the liquid from boiling over and escaping.
Additionally, the rubber stopper or cork can be fitted with a hole through which a thermometer or a condenser can be inserted for monitoring the temperature or conducting a distillation experiment, respectively.The main answer is Boiling chips or stones and a rubber stopper or cork can be used to control boiling when heating liquid in a round bottom flask.: Boiling chips or stones and a rubber stopper or cork can be used to control boiling when heating liquid in a round bottom flask.
To know more about heating visit:
https://brainly.com/question/32093936
#SPJ11
use the following balanced reaction: if you have 7.95 moles of na2co3 and 9.20 moles of ca(hc2h3o2)2, how many moles of nac2h3o2 will be produced? mole nac2h3o2
15.9 moles of NaCH3COO will be produced when 7.95 moles of Na2CO3 and 9.20 moles of Ca(CH3COO)2 react.
The balanced chemical reaction between sodium carbonate and calcium acetate is as follows:
Na2CO3 + Ca(CH3COO)2 → 2NaCH3COO + CaCO3
The stoichiometric ratio between sodium carbonate and calcium acetate in the balanced chemical equation is 1:1. Therefore, if there are 7.95 moles of Na2CO3 and 9.20 moles of Ca(CH3COO)2, the limiting reactant would be Na2CO3 because it is less than Ca(CH3COO)2.
Moles of NaCH3COO produced = Moles of limiting reactant used = 7.95 mol
Now, the balanced chemical equation shows that 1 mole of Na2CO3 produces 2 moles of NaCH3COO, thus:
1 mol of Na2CO3 → 2 mol of NaCH3COO7.95 moles of Na2CO3 → 15.9 moles of NaCH3COO
Therefore, 15.9 moles of NaCH3COO will be produced when 7.95 moles of Na2CO3 and 9.20 moles of Ca(CH3COO)2 react.
To know more about moles visit:
https://brainly.com/question/15209553
#SPJ11
suppose you have 7.0 moles of aqueous barium chloride, and you mix this with aluminum sulfate solution. how many moles of aluminum chloride can you produce? ______moles of aluminum chloride
We can produce approximately 4.67 moles of aluminum chloride.
We need to take into account the stoichiometry of the balanced chemical equation between barium chloride and aluminum chloride to figure out how many moles of aluminum chloride can be made when 7.0 moles of aqueous barium chloride is combined with aluminum sulfate solution.
The reaction between barium chloride[tex](BaCl_2)[/tex] and aluminum sulfate [tex](Al_2(SO_4)_3)[/tex] has the following balanced equation:
[tex]3 BaCl_2 + Al_2(SO_4)_3 - > 2 AlCl_3 + 3 BaSO_4[/tex]
We can conclude from this equation that when 3 moles of barium chloride and 1 mole of aluminum sulfate react, 2 moles of aluminum chloride are formed. So we can make 2 moles of aluminum chloride for every 3 moles of barium chloride.
We can determine the moles of aluminum chloride based on the fact that we have 7.0 moles of barium chloride.
moles of aluminum chloride = (7.0 moles barium chloride) * (2 moles aluminum chloride / 3 moles barium chloride)
So, moles of aluminum chloride = (7.0 * 2) / 3 = 14.0 / 3 ≈ 4.67 moles
Therefore, we can produce approximately 4.67 moles of aluminum chloride.
Learn more about moles here:
https://brainly.com/question/15209553
#SPJ4
A 150 g sample of a compound is comprised of 44% C, 9% H and the remainder is O by mass. What is the compound's empirical formula? Hint: The percentage of all three elements must add up to 100%.
To find the empirical formula of the given compound, follow the steps below: 1. Let's consider the percentages of carbon, hydrogen, and oxygen: 44% C 9% H x% O Now, the sum of all percentages is equal to 100%.
Therefore, the percentage of oxygen can be determined as follows: 44% C + 9% H + x% O = 100% thus, x = 47%. Therefore, the percentages of the elements are as follows: 44% C 9% H 47% O₂. Convert the percentages into the corresponding number of moles of each element: One way of doing this is by assuming that there are 100 g of the compound. This will give us the mass of each element present in the compound as follows: Mass of C = 0.44 × 100 g = 44 g Mass of H = 0.09 × 100 g = 9 g Mass of O = 0.47 × 100 g = 47 g Next, we will find the number of moles of each element present in 100 g of the compound using the atomic masses of the elements: C: atomic mass = 12 g/mol Number of moles of C = 44 g ÷ 12 g/mol = 3.67 mol H: atomic mass = 1 g/mol Number of moles of H = 9 g ÷ 1 g/mol = 9 mol O: atomic mass = 16 g/mol Number of moles of O = 47 g ÷ 16 g/mol = 2.94 mol3.
Find the mole ratio of the elements by dividing the number of moles of each element by the smallest number of moles (in this case, the number of moles of O is the smallest): Number of moles of C = 3.67 mol ÷ 2.94 mol ≈ 1.25Number of moles of H = 9 mol ÷ 2.94 mol ≈ 3.06 Number of moles of O = 2.94 mol ÷ 2.94 mol = 1. The mole ratio of the elements is therefore approximately C.25H₃.06O₁₄. Write the empirical formula by multiplying the subscripts by the smallest whole number that will make them all integers: C1.25H₃.06O₁ × 4 = C₅H₁₂O₄. The empirical formula of the compound is C₅H₁₂O₄.
To know more about compound visit:-
https://brainly.com/question/14117795
#SPJ11
51 mL of 0.060 M NaF is mixed with 17 mL of 0.15 M Sr(NO3)2. Calculate the concentration of Sr2+ in the final solution. Assume volumes can be added. (Ksp for SrF2 = 2.0× 10-10) 0.00012 M 0.045 M 0.075 M 0.015 M 0.0375 M
The correct option is (d) 0.015 M. We need to calculate the concentration of Sr2+ in the final solution. To calculate the concentration of Sr2+ in the final solution, we need to know the number of moles of NaF and Sr(NO3)2 are present in the given solutions.
We need to calculate the concentration of Sr2+ in the final solution. To calculate the concentration of Sr2+ in the final solution, we need to know the number of moles of NaF and Sr(NO3)2 are present in the given solutions. Let us first calculate the number of moles of NaF and Sr(NO3)2. Number of moles of NaF is given by the formula:
Number of moles of NaF = Molarity × Volume (in liters)
Number of moles of NaF = 0.060 M × 51 mL / 1000 mL/L = 0.00306 mol
Number of moles of Sr(NO3)2 is given by the formula
:Number of moles of Sr(NO3)2 = Molarity × Volume (in liters)
Number of moles of Sr(NO3)2 = 0.15 M × 17 mL / 1000 mL/L = 0.00255 mol
Now, we need to check whether any precipitation occurs when NaF and Sr(NO3)2 are mixed together. To do this, we need to calculate the ion product, Qsp.Qsp = [Sr2+][F-]2
Since the volume of the final solution is not given, let us assume that volumes can be added. Therefore, the final volume of the solution is 51 mL + 17 mL = 68 mL. The moles of NaF and Sr(NO3)2 do not change when they are mixed together. Therefore, the number of moles of NaF and Sr(NO3)2 in the final solution is the same as the number of moles in the initial solutions.The final concentration of NaF in the solution is:
Number of moles of NaF = 0.00306 mol
Volume of the solution = 68 mL = 0.068 L
Concentration of NaF = 0.00306 mol / 0.068 L = 0.045 M
Now, we can calculate the concentration of Sr2+ in the final solution using the ion product, Qsp.Qsp = [Sr2+][F-]2Ksp = 2.0 × 10-10
The concentration of F- in the final solution is:
Number of moles of NaF = 0.00306 mol
Volume of the solution = 68 mL = 0.068 L
Concentration of F- = 0.00306 mol / 0.068 L = 0.045 M
Therefore, the ion product, Qsp = [Sr2+][F-]2 = x × (0.045)2
Since 51 mL of 0.060 M NaF is mixed with 17 mL of 0.15 M Sr(NO3)2, the initial concentration of Sr2+ is 0 M. Let x be the concentration of Sr2+ in the final solution. Therefore, the ion product, Qsp = (0.045 - x) × (0.045)2When the system is at equilibrium, Qsp = Ksp.(0.045 - x) × (0.045)2 = 2.0 × 10-10x = 0.015 M
Therefore, the concentration of Sr2+ in the final solution is 0.015 M. Hence, the correct option is (d) 0.015 M.
To know more about concentration visit: https://brainly.com/question/3045247
#SPJ11
Draw the major organic product for the reaction. Hg(OAC)2, H20 -H acetic acid
The major organic product for the reaction
Hg(OAC)2, H2O, -H acetic acid
is Mercury (II) Acetate Monohydrate which is a white crystalline solid that is used in photography and medicine. It is soluble in water and ethanol and is slightly soluble in ether.
The major organic product for the reaction between
Hg(OAC)2 and H2O
in the presence of acetic acid is what we're looking for. Here's the solution to this:
When Hg(OAC)2
reacts with H2O in the presence of acetic acid, the reaction takes place with the replacement of the water molecule by the acetate ion, as shown:
Hg(OAC)2 + H2O → Hg(OAC)OH + HOAC (acetic acid)
Here, the acetate ion works as a nucleophile and attacks the mercury center. The product of this reaction is called mercury (II) acetate monohydrate.Hence, the major organic product for the reaction
Hg(OAC)2, H2O, -H acetic acid
is Mercury (II) Acetate Monohydrate which is a white crystalline solid that is used in photography and medicine. It is soluble in water and ethanol and is slightly soluble in ether.
To know more about crystalline visit:
https://brainly.com/question/32203371
#SPJ11
for a molecule of chlorous acid, the atoms are arranged as hoclo
Chlorous acid, a weak acid with the formula HClO2, can be synthesized by reacting hydrogen peroxide with hypochlorous acid, generating hydrogen chloride and oxygen as by-products. Chlorous acid is a fundamental compound that has a broad range of applications, including disinfection, wastewater treatment, and food preservation.
For a molecule of chlorous acid, the atoms are arranged as HOClo, as you have mentioned in your question. The hydrogen atom is covalently bonded to the oxygen atom, while the oxygen atom is doubly bonded to one of the two chlorine atoms, which is single bonded to the other chlorine atom. The bond angles between the atoms in chlorous acid are not equivalent, with the oxygen-hydrogen and oxygen-chlorine bonds being roughly 110° and 103°, respectively.
The geometry of chlorous acid can be determined using VSEPR theory. According to VSEPR theory, chlorous acid has a bent shape, with a bond angle of approximately 108°. This is due to the presence of two lone pairs of electrons on the oxygen atom, which repel the bonding pairs and cause the molecule to bend.
The acidity of chlorous acid is due to the ease with which the hydrogen atom dissociates from the molecule to form hydronium ions and chlorite ions. The equilibrium constant for the dissociation of chlorous acid is relatively small (approximately 1.1 x 10^-2), indicating that only a small fraction of the chlorous acid molecules will dissociate in solution.
In summary, chlorous acid is a weak acid with the formula HClO2, and the atoms in a molecule of chlorous acid are arranged as HOClo. The geometry of chlorous acid is bent, with a bond angle of approximately 108°, and its acidity is due to the ease with which the hydrogen atom dissociates from the molecule to form hydronium ions and chlorite ions.
To know more about VSEPR theory visit
https://brainly.com/question/17177984
#SPJ11
Which of the following is false?
KCl is a heteronuclear diatomic molecule
H2S is called hydrogen sulfide as a molecule and called hydrosulfuric acid as an acid
HCl is called hydrogen chloride as a molecule and called hydrochloric acid as an acid
H2 is a homonuclear diatomic molecule but is not a compound
NO2 is called nitrogen dioxide and N2O is called dinitrogen monoxide
H2O is a heteronuclear polyatomic molecule and also a compound
HCl is a heteronuclear diatomic molecule and also a compound
HCl is called hydrogen chloride as a molecule and called hydrochloric acid as an acid
The false statement among the given options is : H2 is a homonuclear diatomic molecule but is not a compound.What is a diatomic molecule?Diatomic molecules are molecules that contain two atoms, typically of the same or similar chemical elements.
The atoms in a diatomic molecule can be the same (homonuclear molecules) or different (heteronuclear molecules).For instance, H2, N2, O2, F2, Cl2, Br2, and I2 are examples of homonuclear diatomic molecules. A compound is a substance that contains two or more elements that are chemically bonded together.
A compound is composed of atoms of two or more different elements combined in a fixed proportion.The false statement among the given options is "H2 is a homonuclear diatomic molecule but is not a compound."
To know more about homonuclear visit :
https://brainly.com/question/29195136
#SPJ11
how many milliliters of 1 m acetic acid are required to neutralize a reaction containing 1.2 g of k2co3?
We need to find out the milliliters of 1 M acetic acid required to neutralize the given amount of K2CO3.First, we'll have to find the number of moles of K2CO3, which can be calculated using the formula.
Number of moles = Mass/Molar mass Molar mass of Number of moles of K2CO3 = 1.2 g / 138.21 g/mol = 0.00867 molesWe know that 1 mole of K2CO3 requires 2 moles of acetic acid to get neutralized.So, the number of moles of acetic acid required to neutralize 0.00867 moles of K2CO3 will be:2 x 0.00867 moles = 0.01734 moles.
Now, let's calculate the volume of 1 M acetic acid required.Number of moles = Molarity x VolumeVolume = Number of moles / MolarityVolume = 0.01734 moles / 1 MVolume = 17.34 milliliters Hence, 17.34 milliliters of 1 M acetic acid is required to neutralize 1.2 g of K2CO3.
To know more about neutralize visit :
https://brainly.com/question/15395418
#SPJ11
a sample of ethanol, c2h6o, has a mass of 37.25 g. calculate the number of ethanol molecules in the sample.
The number of ethanol molecules in the sample can be calculated using the mass of ethanol and Avogadro's number. The given molecular formula of ethanol is C2H6O and its molar mass is 46.07 g/mol.
How to calculate the number of ethanol molecules in the sample?
Step 1: Calculate the number of moles of ethanol in the sample.
Number of moles of ethanol = mass of ethanol / molar mass of ethanol
= 37.25 g / 46.07 g/mol = 0.807 mol
Step 2: Use Avogadro's number to convert the number of moles of ethanol to the number of ethanol molecules in the sample.
The Avogadro's number (Na) is equal to 6.022 × 1023 mol-1.
Number of ethanol molecules in the sample = Number of moles of ethanol × Avogadro's number
= 0.807 mol × 6.022 × 1023 mol-1
= 4.861 × 1023 ethanol molecules
Therefore, there are 4.861 × 1023 ethanol molecules in the sample.
Learn more about the Avogadro's number:
brainly.com/question/859564
#SPJ11
identify the element with the highest standard free energy of formation. k (s) li (s) ba (s) ca (s) all elements have a value of zero.
The main answer to this question is lithium. The explanation for this is that Li (lithium) has the highest standard free energy of formation (ΔGf° = 0 kJ/mol) among all elements.
What is standard free energy of formation?The standard free energy of formation (ΔGf°) is a thermodynamic function that provides the change in free energy as one mole of a compound is formed from its constituent elements at standard conditions (298 K and 1 atm). The standard free energy of formation of an element in its standard state is always zero.How do you calculate standard free energy of formation?
We can calculate ΔGf° of a compound using Hess's law, which states that the enthalpy change for a reaction is the sum of the enthalpy changes for any number of reactions that add up to the overall reaction. We can use Hess's law to calculate ΔGf° for a given compound using standard free energies of formation of its constituent elements as given below:ΔGf°(compound) = Σn ΔGf°(products) - Σm ΔGf°(reactants)Where n and m are stoichiometric coefficients of products and reactants, respectively.
To know more about elements visit:
https://brainly.com/question/24611426
#SPJ11
Suppose we have 1,000,000 identical nuclei with a half-life of 20 min. Approximately how many nuclei will be left after 100 min?
A. 500
B. 1
C. 10,000
D. 31,250
E. 200,000
F. 0
The radioactive decay law states that the number of radioactive nuclei decays exponentially with time. After 100 min, approximately 327,700 nuclei will be left, which is closest to the option E.
The radioactive decay law states that the number of radioactive nuclei decays exponentially with time. The decay law can be expressed as, N(t) = N₀e⁻ᴧᵗ
Where, N₀ is the number of nuclei present at t = 0, N(t) is the number of nuclei present at time t, and ᴧ is the decay constant. The half-life is the time taken for half of the radioactive nuclei to decay. Hence, using the decay law, the number of radioactive nuclei remaining after a time interval t can be given as,N(t) = N₀e⁻ᴧᵗ
Approximately how many nuclei will be left after 100 min if there were 1,000,000 identical nuclei with a half-life of 20 min? Given, Half-life of nuclei = 20 min
Therefore, Decay constant, ᴧ = ln2/T½ = ln2/20The time interval is t = 100 min. Substituting the values in the decay law equation, N(100) = N₀e⁻ᴧᵗN(100) = 1,000,000e⁻⁵N(100) = 1,000,000(0.3277)N(100) = 327,700
Thus, after 100 min, approximately 327,700 nuclei will be left, which is closest to the option E.
To know more about nuclei visit: https://brainly.com/question/32368659
#SPJ11
A compound with a composition of 87.5%N and 12.5%H was recently discovered. The empirical formula for this compound is: -NH2, -N2H2, -N2H3, -NH.
The given compound has a composition of 87.5% nitrogen (N) and 12.5% hydrogen (H). What is the empirical formula for this compound The empirical formula for the given compound is NH2.
What is the empirical formula The empirical formula of a chemical compound is the simplest possible formula consisting of only whole numbers that represent the ratio of the elements present in the compound. The empirical formula does not necessarily represent the actual molecular formula of the compound. In this problem, we are given the composition of a compound in terms of percentage by weight of each element. The percentages given are 87.5% N and 12.5% H.
To determine the empirical formula, we need to convert the percentage composition to mole ratio.We can assume a 100 g sample of the compound so that we have 87.5 g of N and 12.5 g of H. We then convert these masses to moles using the molar mass of each element:Atomic mass of N = 14.01 g/molAtomic mass of H = 1.01 g/molMoles of N = 87.5 g / 14.01 g/mol = 6.24 molMoles of H = 12.5 g / 1.01 g/mol = 12.38 molWe divide the number of moles by the smaller value of moles to get the simplest ratio of N to H:Moles of N / Moles of H = 6.24 mol / 12.38 mol = 0.50/1 ≈ 1/2We multiply the ratio by 2 to get whole numbers: N1H2 or NH2, which is the empirical formula of the compound. A compound with a composition of 87.5% N and 12.5% H has the empirical formula NH2.
To know more about hydrogen visit :
https://brainly.com/question/30623765
#SPJ11
Which of the following, when added to pure water, will increase the pH of the solution at 25 degree C? i. KBr ii. KCN iii. FeBr_3 iv. NaCIO_4 v. NH_4Br A. i and iv B. ii and iv C. iii and v D. ii only E. All of the salts will increase the pH of the aqueous solution
The answer is option D. ii only. When added to pure water at 25 degrees Celsius, only KCN will increase the pH of the solution.
The pH of a solution indicates its acidity or alkalinity. pH values below 7 indicate acidity, while values above 7 indicate alkalinity. In this case, we need to determine which salt will act as a base and increase the pH of water.
i. KBr: KBr is a neutral salt and does not affect the pH of water.
ii. KCN: KCN is a salt of a weak acid (HCN) and a strong base (KOH). The presence of the weak acid HCN in the solution will react with water to form H+ ions and CN- ions. This will increase the concentration of hydroxide ions (OH-) in the solution, resulting in an increase in pH.
iii. [tex]FeBr_3: FeBr_3[/tex] is a neutral salt and does not affect the pH of water.
iv. [tex]NaCIO_4[/tex]: [tex]NaCIO_4[/tex] is a neutral salt and does not affect the pH of water.
v. [tex]NH_4Br: NH_4Br[/tex] is a neutral salt and does not affect the pH of water.
Therefore, only KCN, option ii, will increase the pH of the aqueous solution.
To learn more about pH refer:
https://brainly.com/question/172153
#SPJ11
for a given reaction, δh = 35.5 kj/mol and δs = 83.6 j/kmol. the reaction is spontaneous ________. assume that δh and δs do not vary with temperature.
For a given reaction, δH = 35.5 kJ/mol and δS = 83.6 J/Kmol, the reaction is spontaneous at a temperature greater than 151 °C.
However, we need to determine the temperature of the reaction to specify the extent of the reaction and the direction of the process. Spontaneous processes are spontaneous in the forward direction only if the change in free energy is negative, which is given by ΔG = ΔH - TΔS. ΔG is negative for spontaneous reactions, while ΔG is positive for non-spontaneous reactions. ΔG is zero for reactions in a state of equilibrium.Due to the given parameters, the reaction is spontaneous. ΔS is positive because the number of moles of gas increases from the reactant to the product, resulting in greater disorder. ΔH is also positive because the reaction is endothermic.
Since ΔG = ΔH - TΔS, we may deduce that the reaction is spontaneous at a temperature greater than ΔH/ΔS = (35.5 kJ/mol)/(83.6 J/Kmol) = 424 K or 151 °C.
To know more about temperature visit:
https://brainly.com/question/11464844
#SPJ11
a series of elementary reactions by which reactants are converted to products is called the reaction__
The term that completes the sentence "A series of elementary reactions by which reactants are converted to products is called the reaction " is "mechanism".
Explanation: A reaction mechanism is the step-by-step process of how a chemical reaction occurs. It describes the overall process of the reaction along with the order and rates of each step in the reaction. A reaction mechanism usually consists of a series of elementary steps (reactions) by which reactants are converted to products.In addition to elementary steps, there may be intermediates that form during the reaction process, which are the chemicals that form between the reactants and the products.
These intermediates have a finite lifetime before they react further to produce the final product. So, a reaction mechanism includes both elementary reactions and the formation of intermediates that react further to form the final product.
To know more about chemical reaction refer to:
https://brainly.com/question/25769000
#SPJ11
Use a periodic table to answer the following questions. a. Fluorine gas consiss of diatomic molecules of fluorine (F2). How many molecule of fluorine are in one mole of fluorine? 6.022×1023 b. What is the mass of 1 mole of fluorine gas? 18.998 g/mol c. How many atoms of fluorine are in this sample? Show your work.
That implies that the number of atoms is 2 x 6.022 x 1023, which is 1.204 x 1024 atoms. Thus, the number of atoms of fluorine in the given sample is 1.204 x 1024 atoms.
a. Fluorine gas consists of diatomic molecules of fluorine (F2). How many molecules of fluorine are in one mole of fluorine?One mole of fluorine contains 6.022 × 1023 molecules of fluorine.
Fluorine is a diatomic gas with the molecular formula F2. It indicates that a fluorine molecule is made up of two fluorine atoms. Thus, there are two atoms of fluorine in each molecule.b. What is the mass of 1 mole of fluorine gas?
The mass of one mole of a substance is called the molar mass. The molar mass of fluorine gas is 18.998 g/mol. Hence, the mass of 1 mole of fluorine gas is 18.998 g/mol.c.
How many atoms of fluorine are in this sample? Show your work.1 mole of fluorine has 6.022 x 1023 molecules of F2, which contains 2 fluorine atoms.
To know more about atoms visit:
https://brainly.com/question/1566330
#SPJ11
at 25 °c, only 0.0630 mol of the generic salt ab2 is soluble in 1.00 l of water. what is the sp of the salt at 25 °c? ab2(s)↽−−⇀a2 (aq) 2b−(aq)
The Ksp of the generic salt AB2 at 25 °C is 0.0010 mol3/L3.
The solubility product constant (Ksp) of the generic salt AB2 can be calculated using the given data. We are given that 0.0630 mol of the salt AB2 is soluble in 1.00 L of water at 25 °C.
Using this data, we can calculate the concentration of A2 and B- ions as follows:0.0630 mol of AB2 produces 0.0630 mol of A2 ions and 0.1260 mol of B- ions.
Since the volume of the solution is 1.00 L, the concentration of A2 ions is 0.0630 M, and the concentration of B- ions is 0.1260 M.Now, let's use these concentrations to calculate the Ksp of AB2.
The dissociation of AB2 in water can be represented by the following balanced chemical equation.
AB2(s) ⇌ A2+(aq) + 2B-(aq)
The Ksp expression for AB2 can be written as follows:
Ksp = [A2+][B-]2
Substituting the molar concentrations of A2+ and B- into this equation, we get:
Ksp = (0.0630 M)(0.1260 M)2= 0.0009991 mol3/L3.
Rounding this value to two significant figures, we get Ksp = 0.0010 mol3/L3.
Therefore, the Ksp of the generic salt AB2 at 25 °C is 0.0010 mol3/L3.
Learn more about solubility product at: https://brainly.com/question/1419865
#SPJ11
draw the conjugate acid for the following base (lone pairs do not have to be drawn):
The conjugate acid has one more H+ ion than the base and its chemical formula is written with H+ as the cation.
In order to draw the conjugate acid for a base, it is important to understand the concept of Bronsted-Lowry acids and bases. According to the Bronsted-Lowry theory, an acid is a substance that donates a proton (H+) and a base is a substance that accepts a proton.To draw the conjugate acid for a base, you need to add a proton to the base. The conjugate acid will have one more H+ ion than the base and its chemical formula will be written with H+ as the cation. For example, NH3 is a base and its conjugate acid is NH4+.
Here are a few steps to draw the conjugate acid for a base:
1. Identify the base that you want to draw the conjugate acid for.
2. Add a proton (H+) to the base.
3. Write the chemical formula for the conjugate acid, with H+ as the cation.
For example, let's say the base is OH-. The conjugate acid will be H2O, since H+ will be added to OH- to form H2O.OH- + H+ → H2O
Therefore, the conjugate acid for the base OH- is H2O.In conclusion, the conjugate acid for a base is obtained by adding a proton to the base.
To know more about conjugate acid visit:
https://brainly.com/question/16428518
#SPJ11
The molecular structure of polymers may be described as a long chain of repeating molecular units.
True or false?
The molecular structure of polymers may be described as a long chain of repeating molecular units. This statement is True.
The molecular structure of polymers is characterized by a long chain of repeating molecular units, also known as monomers. This repeated arrangement forms the backbone of the polymer and contributes to its unique properties. Polymers are formed through a process called polymerization, where monomers join together via chemical bonds to create a larger and more complex structure. The repetition of these monomers along the polymer chain allows for the amplification of specific characteristics and behavior.Each monomer unit in a polymer contributes to its overall structure and properties. The arrangement and sequence of monomers can vary, resulting in different types of polymers with distinct chemical, physical, and mechanical properties. For example, linear polymers have a straightforward chain structure, while branched polymers have additional side chains branching off the main chain.The concept of a long chain of repeating units is fundamental to understanding the behavior of polymers. It enables polymers to exhibit characteristics such as high molecular weight, flexibility, durability, and diverse applications in various industries, including plastics, textiles, coatings, and adhesives. The ability to manipulate the molecular structure of polymers through the choice of monomers and polymerization techniques allows for the development of tailored materials with specific properties and performance.
To know more about polymerization, click here https://brainly.com/question/27354910
#SPJ11
Molecules with polar bonds typically dissolve in water. The Images below represent the four classes of organic molecules. Click on the organic molecules that will ikely dissolve in water H-C-H H-C-H H-C-H H-C-H H-C-H N-H H OH HVH
The molecule that will likely dissolve in water is H OH (hydroxyl group), which is present in carbohydrates, proteins, and nucleic acids.
Polar bonds are covalent bonds where there is a separation of electric charge, and this difference arises from differences in the electronegativity of the atoms forming the bond. The electronegativity is defined as the ability of an atom to attract electrons towards itself in a covalent bond. The molecule's polarity determines its solubility in water.
For example, polar molecules are generally more soluble in water than nonpolar molecules. Water molecules have a positive end and a negative end, and they are attracted to the polar regions of a molecule. Organic molecules are molecules that contain carbon atoms. The four classes of organic molecules are carbohydrates, lipids, proteins, and nucleic acids.
The molecule that will likely dissolve in water is H OH (hydroxyl group), which is present in carbohydrates, proteins, and nucleic acids. Hydroxyl groups are polar and can form hydrogen bonds with water molecules. Polar bonds are responsible for water solubility.
In conclusion, polar molecules dissolve in water because they have the same or similar properties to water. They have a polarity that allows them to interact with water molecules, which makes them dissolve in water. The molecule with the hydroxyl group is likely to dissolve in water.
For more information on polar bonds : https://brainly.com/question/29144393
#SPJ11
be sure to answer all parts a 10.0−ml solution of 0.660 m nh3 is titrated with a 0.220 m hcl solution. calculate the ph after the following additions of the hcl solution:
The pH of the solution remains constant at 4.74 with 0.0 mL of HCl, becomes neutral (pH 7) with 10.0 mL of HCl, and becomes increasingly acidic with 30.0 mL (pH 3.37) and 40.0 mL (pH 2.19) of HCl added.
a) V₂=0.0 mL
In this case, there is no HCl added to the NH₃ solution, so the pH will be equal to the pKb of NH₃, which is 4.74.
b) V₂=10.0 mL
In this case, the moles of HCl added is equal to the moles of NH₃ in the solution. The reaction between HCl and NH₃ is:
NH₃ + HCl → NH₄Cl
This reaction produces a salt, NH₄Cl, which is a neutral salt. Therefore, the pH of the solution after the addition of 10.0 mL of HCl will be 7.0.
c) V₂ =30.0 mL
In this case, the moles of HCl added is greater than the moles of NH₃ in the solution. The excess HCl will react with water to produce hydronium ions, which will make the solution acidic. The pH of the solution after the addition of 30.0 mL of HCl can be calculated using the following equation:
pH = -log[H⁺]
where [H⁺] is the concentration of hydronium ions. The concentration of hydronium ions can be calculated using the following equation:
[tex][H+] = \frac{C_2V_2}{V_1 + V_2}[/tex]
where C₂ is the concentration of HCl solution, V₂ is the volume of HCl solution added, and V₁ is the initial volume of NH₃ solution.
Substituting the given values, we get:
[tex][H+] = \frac{0.220\ \text{M} \cdot 30.0\ \text{mL}}{10.0\ \text{mL} + 30.0\ \text{mL}} = 0.440\ \text{M}[/tex]
Therefore, the pH of the solution after the addition of 30.0 mL of HCl is:
[tex]pH = -log(0.440\ \text{M}) = 3.37[/tex]
d) V₂=40.0 mL
In this case, the moles of HCl added is twice the moles of NH₃ in the solution. The excess HCl will react with water to produce hydronium ions, which will make the solution even more acidic. The pH of the solution after the addition of 40.0 mL of HCl can be calculated using the same equation as above.
Substituting the given values, we get:
[tex][H+] = \frac{0.220\ \text{M} \cdot 40.0\ \text{mL}}{10.0\ \text{mL} + 40.0\ \text{mL}} = 0.660\ \text{M}[/tex]
Therefore, the pH of the solution after the addition of 40.0 mL of HCl is:
[tex]pH = -log(0.660\ \text{M}) = 2.19[/tex]
Conclusion:
The pH of the solution after the addition of HCl will increase as the volume of HCl added increases. This is because the excess HCl will react with water to produce hydronium ions, which will make the solution acidic.
To know more about the pH of the solution refer here :
https://brainly.com/question/23857908#
#SPJ11
Write the balanced chemical equation for each of the reactions. Include phases. When aqueous sodium hydroxide is added to a solution containing lead(II) nitrate, a solid precipitate forms.
equation:
However, when additional aqueous hydroxide is added, the precipitate redissolves, forming a soluble [Pb(OH)4]2−(aq) complex ion.
The balanced chemical equation for the reaction between aqueous sodium hydroxide and lead(II) nitrate is: 2NaOH(aq) + Pb(NO₃ )₂(aq) → Pb(OH)₂(s) + 2NaNO₃ (aq)
When additional aqueous hydroxide is added, the precipitate redissolves, forming the soluble complex ion [Pb(OH)₄]₂-(aq).
What is the balanced chemical equation for the reaction between sodium hydroxide and lead(II) nitrate, and what happens when additional hydroxide is added?
When aqueous sodium hydroxide (NaOH) is added to a solution containing lead(II) nitrate (Pb(NO₃)₂), a double displacement reaction occurs.
The sodium ions (Na+) from NaOH exchange places with the lead(II) ions (Pb2+) from Pb(NO₃)₂, forming insoluble lead(II) hydroxide (Pb(OH)2) as a solid precipitate. The balanced chemical equation for this reaction is: 2NaOH(aq) + Pb(NO₃)₂(aq) → Pb(OH)₂(s) + 2NaNO₃(aq).
However, when additional aqueous hydroxide is added, the precipitate of Pb(OH)₂ redissolves. This is because excess hydroxide ions react with the lead(II) hydroxide to form a soluble complex ion called [Pb(OH)₄]₂-(aq).
The balanced equation for this dissolution reaction is not necessary for the given question, but it can be represented as: Pb(OH)₂(s) + 4OH-(aq) → [Pb(OH)₄]₂-(aq).
The redissolution of the precipitate occurs due to the formation of a complex ion that has a higher solubility than the original solid. The complex ion [Pb(OH)₄]₂-(aq) is stabilized by the presence of excess hydroxide ions, which coordinate with the lead(II) ion and increase its solubility in water.
Learn more about: Chemical equation
brainly.com/question/28792948
#SPJ11
a. what is the ph of a buffer solution that is 0.14 m and 0.14 m ? for is . ph = b. what is the ph if 15 ml of 0.13 m hydrochloric acid is added to 495 ml of this buffer?
a. The pH of a buffer solution that is 0.14 M and 0.14 M is given by pH = pKa + log {[A-]/[HA]}Where [HA] = molarity of the weak acid and [A-] = molarity of the conjugate basepKa = -log(Ka)Ka = Acid dissociation constant.
pKa of a buffer solution = 4.5 (average of 4.48 and 4.52)Molarity of weak acid, [HA] = 0.14 Molarity of conjugate base, [A-] = 0.14 pH = pKa + log {[A-]/[HA]}= 4.5 + log {0.14/0.14}= 4.5 + log {1} = 4.5b. The pH when 15 mL of 0.13 M hydrochloric acid is added to 495 mL of the buffer is given by the following:moles of hydrochloric acid = 15 x 0.13/1000 = 0.00195 molmoles of the weak acid in the buffer = 495 x 0.14 = 0.0693 molmoles of the conjugate base in the buffer = 495 x 0.14 = 0.0693 mol
Total volume of the solution after adding HCl = 15 mL + 495 mL = 510 mLPH = pKa + log {[A-]/[HA]} + log {moles of strong acid/moles of weak acid}= 4.5 + log {0.14/0.14} + log {(0.00195 mol)/(0.0693 mol)}= 4.5 + log {1} + log {0.0281}= 4.5 + 0 + (-1.552)= 2.95
To know more about molarity visit:
https://brainly.com/question/31545539
#SPJ11
1.0 mol of an ideal
gas starts at 1.0 atm and 77F and does 1.0 kJ of work during an
adiabatic expansion. Calculate the final volume of the gas. Express
your answer in litres. In your calculation, f
The final volume of the gas is 15.8 L.
The Ideal gas law is the equation of state of a hypothetical ideal gas. It is a good approximation to the behaviour of many gases under many conditions, although it has several limitations. The ideal gas equation can be written as-
PV = nRT
where,
P = Pressure
V = Volume
T = Temperature
n = number of moles
Given,
n = 1
Pressure = 1 atm
W = 1 kJ
Temperature = 77⁰F
γ = 1.4
PV = nRT
The temperature in K is written as -
T = ( 77 - 32 ) 5/9 + 273.15
= 298.15 K
[tex]w = \frac{nr( T_{1} - T_{2)} }{\pi - 1}[/tex]
T₂ = 250.04 K
The initial volume of the container is -
P₁V₁ = nRT₁
101.32 Pa × V = 1 × 8.314 × 298
V = 0.025 m³
The final volume of the gas is worked out from the equation -
[tex](\frac{V_{2} }{V_{1} } ) = (\frac{T_{1} }{T_{2} })^{(1.4 - 1)}[/tex]
V = 0.0158 m³ = 15.8 L
Learn more about Ideal gas Law, here:
https://brainly.com/question/12624936
#SPJ4
why was cacl2 used and not nacl in the preparation of macrocapsule?
The reason why CaCl2 is used and not NaCl in the preparation of macrocapsules is due to the difference in solubility. Calcium chloride is a salt that is soluble in water, whereas sodium chloride is also soluble in water, but less so than calcium chloride.
A macrocapsule is a type of capsule that is large enough to be seen with the unaided eye. It is also known as a "large capsule." Macrocapsules are usually used in the medical industry to deliver drugs or other substances to specific parts of the body. The substance to be delivered is typically contained within the capsule, which is then implanted into the body.
In order to prepare macro-capsules, a process known as microencapsulation is used. During this process, the substance to be encapsulated is suspended in a solution, and then this solution is mixed with a polymer. The polymer hardens around the substance, creating a capsule that can be implanted into the body.
In the preparation of macro-capsules, CaCl2 is used instead of NaCl because of its solubility. Calcium chloride is highly soluble in water, which makes it ideal for use in the microencapsulation process. The solubility of CaCl2 allows for the formation of a hard, impermeable capsule that is able to protect the substance inside from the surrounding environment. On the other hand, NaCl is less soluble in water than CaCl2, which makes it unsuitable for the microencapsulation process.
Other factors which make CaCl2 suitable for macrocapsule preparation include:
Gel formation: CaCl2 can participate in gel formation reactions with certain polymers or gelling agents. It can crosslink polymers, resulting in the formation of a stable gel structure, which can be useful for encapsulating materials and providing mechanical stability to the macro-capsules.
Compatibility: The specific material being encapsulated or the application of the macrocapsules may require compatibility with CaCl2 rather than NaCl. For example, certain biological or chemical processes may be more compatible with CaCl2 as a component of the encapsulation system.
Learn more about solubility: https://brainly.com/question/24057916
#SPJ11
