Taking into account the definition of pH and pOH, the concentration of OH⁻ is 1×10⁻² M.
Definition of pHpH is a measure of acidity or alkalinity that indicates the amount of hydrogen ions present in a solution or substance.
The pH is defined as the negative base 10 logarithm of the activity of hydrogen ions:
pH= - log [H⁺]
Definition of pOHSimilarly, pOH is a measure of hydroxyl ions in a solution and is expressed as the logarithm of the concentration of OH⁻ ions, with the sign changed:
pOH= - log [OH⁻]
Relationship between pH and pOHThe following relationship can be established between pH and pOH:
pOH + pH= 14
Concentration of OH⁻Being [H⁺]=1.0×10⁻¹² M, the pH is calculated as:
pH= - log (1.0×10⁻¹² M)
Solving:
pH= 12
Being pH= 4.85, and considering the relationship between pH and pOH, pOH is calculated as:
pOH + 12= 14
pOH= 14 - 12
pOH= 2
Replacing in the definition of pOH the concentration of OH⁻ ions is obtained:
- log [OH⁻]= 2
Solving
[OH⁻]= 10⁻²
[OH⁻]= 1×10⁻² M
In summary, the [OH⁻] is 1×10⁻² M.
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Question 16 of 25According to the Gibbs free energy equation, AG = AH-TAS, when is areaction always spontaneous?A. When AH and AS are both positiveB. When AH is negative and AS is positiveC. When AH is positive and AS is negativeD. When AH and AS are both negativeSUBMIT
Answer
B. When ΔH is negative and ΔS is positive
Explanation
The spontaneity of a reaction can be determined by the sign of the Gibbs free energy change. For a spontaneous reaction, the change in Gibbs free energy should be negative, that is:
[tex]\Delta G=\Delta H-T\Delta S[/tex]The spontaneity of a process can depend on the temperature. Since the temperature value here corresponds to the absolute temperature, this implies that T > 0 for any T. Therefore, to have a negative difference for any temperature value, the change in enthalpy (ΔH), should be negative and the change in entropy (ΔS) should be positive so that we always subtract a positive number from a negative number. This corresponds to a negative value in ΔG.
Hence, the
Chemistry Electromagnetic Radiation HW Help. Pls real answers
The frequency of the green light from a traffic signal is 5.76 * 10¹⁴ Hz
The frequency of the light is 1.85 * 10¹⁶ Hz
The frequency of the light is 4.84 * 10¹⁴ Hz
The energy of the photons is 1.172 * 10⁻³ J
The energy of the photons is 4.34 * 10⁻² J
What is the frequency of light wave given the wavelength?The frequency of light can be found given the wavelength from the formula below:
frequency = velocity / wavelength8. The frequency of the green light from a traffic signal is calculated below:
velocity of light = 3.0 * 10⁸ m/s
wavelength = 5.2 x 10⁻⁷ m
Frequency = 3.0 * 10⁸ / 5.2 x 10⁻⁷
frequency = 5.76 * 10¹⁴ Hz
9. The frequency of the light is calculated below:
velocity of light = 3.0 * 10⁸ m/s
wavelength = 16.23 x 10⁻⁹ m
Frequency = 3.0 * 10⁸ / 16.23 x 10⁻⁹
frequency = 1.85 * 10¹⁶ Hz
10. The frequency of the light is calculated below:
velocity of light = 3.0 * 10⁸ m/s
wavelength = 6.2 x 10⁻⁷ m
Frequency = 3.0 * 10⁸ / 6.2 x 10⁻⁷
frequency = 4.84 * 10¹⁴ Hz
11. The energy of one of the photons will be calculated as follows:
E = hf
E = hc/λ
Energy of the photons = 2.3 x 10¹¹ x hc/λ
h = 6.626 * 10⁻³⁴Js
λ = 3.9 x 10⁻¹² m
c = 3.0 * 10⁸ m/s
E = 2.3 x 10¹¹ x 6.626 * 10⁻³⁴ * 3.0 * 10⁸ / 3.9 x 10⁻¹²
E = 1.172 * 10⁻³ J
12. The energy of one of the photons will be calculated as follows:
E = hf
E = hc/λ
Energy of the photons = 9.4 x 10¹⁶ x hc/λ
h = 6.626 * 10⁻³⁴Js
λ = 4.3 x 10⁻⁷ m
c = 3.0 * 10⁸ m/s
E = 9.4 x 10¹⁶ x 6.626 * 10⁻³⁴ * 3.0 * 10⁸ / 4.3 x 10⁻⁷
E = 4.34 * 10⁻² J
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Which of the following is the ground-state electron configuration of a calcium atom?
O a. [Ne]3s²
O b. [Ne]3s²3p6
OC. [Ar]3d²
O d. [Ar]4s²
O e. [Ar]4s¹3d1
The arrangement of electrons in orbitals around an atomic nucleus is known as electronic configuration. It is also known as electronic structure or electron configuration. It follows Aufbau's principle, Hund's rule and Pauli's exclusion principle, to fill the electrons in various orbitals according to the energy of the orbitals.
Calcium has 20 electrons, that is, the atomic number of Ca = 20
Hence its electronic configuration will be, 1[tex]s^{2}[/tex] 2[tex]s^{2}[/tex] 2[tex]p^{6}[/tex] 3[tex]s^{2}[/tex] 3[tex]p^{6}[/tex] 4[tex]s^{2}[/tex]
Now, since Argon has 18 electrons, that is, the atomic number of Ar = 18, its electronic configuration will be,
Ar = 1[tex]s^{2}[/tex] 2[tex]s^{2}[/tex] 2[tex]p^{6}[/tex] 3[tex]s^{2}[/tex] 3[tex]p^{6}[/tex]
Thus , the simplified electronic configuration of Calcium is,
Ca = [Ar]4[tex]s^{2}[/tex]
Thus, option d) [Ar]4[tex]s^{2}[/tex] is the correct answer.
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There are 4 moles of methane burned to produce how many moles of water? CH4+2O2=CO2+2H2O
ANSWER
8 moles of water
EXPLANATION
The major products formed when an organic compound undergo combustion reaction are water and carbon dioxide
Below is the combustion formula
[tex]\text{ C}_xH_y\text{ + x + }\frac{y}{4}O_2\text{ }\rightarrow\text{ xCO}_2\text{ + }\frac{y}{2}H_2O[/tex]In the question above, 4 moles of methane reacts with oxygen
[tex]\begin{gathered} \text{ 4CH}_4\text{ + 4+}\frac{16}{4}O_2\text{ }\rightarrow\text{ 4CO}_2\text{ + }\frac{16}{2}H_2O \\ \\ \text{ 4CH}_{4(g)}\text{ + 8O}_{2(g)}\text{ }\rightarrow\text{ 4CO}_{2(g)}\text{ + 8H}_2O(l) \end{gathered}[/tex]Therefore, 4 moles of methane will give 8 moles of water
If 21.5 g of LiCl are dissolved 450.0 g of water at 20.0 °C in an insulated container, a temperature change is observed. The ∆H of solution of LiCl is -37.0 kJ/mol. Assuming that the specific heat of the solution is 4.184 J/(g°C), and that no heat is gained or lost by the container, what will be the final temperature of the solution?
The final temperature of the solution will be 29.5 °C.
What is the heat released when 21.5 g of LiCl is dissolved completely in water?The heat released when 21.5 g of LiCl is dissolved completely in water is determined from the enthalpy change, ∆H of the solution of LiCl as follows;
Moles of LiCl in 21.5 g = mass/ molar mass
molar mas of LiCl = 42.5 g/mol
Moles of LiCl in 21.5 g = 21.5/42.5
Moles of LiCl in 21.5 g = 0.506 moles
Heat released = 0.506 * -37.0 kJ/mol
Heat released = 18.722 kJ or 18722 J
Heat released = heat gained by solution
Temperature change of the solution = heat gained / mass * specific heat capacitymass of solution = 450 + 21.5
mass of solution = 471.5 g
Temperature change of the solution = 18722 / (471.5 * 4.184)
Temperature change of the solution = 9.5 °C
Final temperature of the solution = 20 °C + 9.5 °C
Final temperature of the solution =29.5 °C
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Humans have been smelting ore for thousands of years. Ancient humans smelted ore to make all but which of the following
Answer
wiring
Explanation
Ancient humans did make jewelry, weapons and tools by smoltering ore, however, they did not make wires, hence there was no electricity in many mnay years ago.
A 25.0 mL aliquot was taken from a 500.0 mL sample of tonic water containing an unknown amount of quinine and diluted to a volume of 200.0 mL. At 347.5 nm, the fluorescence intensity of the diluted sample was measured as 73.7 on an arbitrary scale. Under similar conditions, a 25.0 ppm standard quinine solution had a fluorescence intensity of 195 . Calculate the mass of quinine in the original tonic water sample.
The mass of quinine in the original tonic water sample is 37.8 mg.
What is the concentration of the diluted sample?The concentration of the diluted sample with a fluorescence intensity of 73.7 is calculated using the formula of Lambert-Beer's law as follows:
C₁/C₂ = A₁/A₂
where:
C₁ = 25 ppm or 25 mg/L
C₂ = ?
A₁ = 195
A₂ = 73.7
C₂ = 73.7 * 25 / 195
C₂ = 9.45 mg/L
To concentration of the original sample will be determined from the dilution formula:
C₁V₁ = C₂V₂
where;
C₁ = ?
V₁ = 25. 0 mL
C₂ = 9.45 mg/L
V₂ = 200 mL
C₁ = 9.45 * 200 / 25
C₁ = 75.6 mg/L
The volume of the stock sample was 500 mL or 0.5 L
The mass of quinine = 75.6 mg/L * 0.5 L
mass of quinine = 37.8 mg
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Define hydrogen bonding and explain how hydrogen are bonding involved in the
transfer of genetic material.
Answer:
Hydrogen bonding is a special type of dipole-dipole attraction between molecules, not a covalent bond to a hydrogen atom. It results from the attractive force between a hydrogen atom covalently bonded to a very electronegative atom such as a N, O, or F atom and another very electronegative atom.
Explanation:
Experiment 2: Copper(II) carbonate hydroxide produces one mole of water (=18.015 g/mol) for every two moles of solid product (=79.545 g/mol) produced. If 3.597 g of solid product were produced during the reaction, how many grams of water were realeased as water vapor?
1. How would an element be classified?a. homogeneous mixtureb. pure substancec. solutiond. heterogeneous mixture
Hello
To solve this question, we should understand that an element is is the base form in which a particule exit. However, it can either be in a molecule, atom or in a compound. Elements are pure substance which form up the molecule, atom or compounds. An element can said to be an identity of a substance. Elements are generally classified using the periodic table into metals, non-metals, metalliods.
In this question, the most possibe defination is that an element is a pure substance
A homogenous mixture is a mixture that is said to have one phase of substance throughout. I.e the comprising substance are all in a single phase.
A solution is the mixture of a solute that is completely dissolved in a solvent.
A heterogeneous mixture is a solution that the substance are not in a single phase.
The answer to this question is option B
Complete the table below by deciding whether a precipitate forms when aqueous solutions A and B are mixed. If a precipitate will form, enter its empirical formula in the last column.
1) A precipitate called [tex]Fe(OH)_{2}[/tex]
2) A precipitate is formed called [tex]Mg(CH_{3} COO)_{2}[/tex]
What is a precipitate?The term precipitate is used to describe the product that is formed when there is a reaction between two aqueous phase reactants that leads to the formation of a solid product from the reaction as we can see from the image that is attached.
we now have to look at the reactions as we can see them in the mage that is attached. We must note that we can only say that a precipitate has been formed if the product is solid after we have mixed the aqueous phase reactants.
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What wavelength (in nm) of light is emitted when an electron transitions from the n = 12 to the n = 1 state?
The wavelength of the light in this case is 92 nm
What is the Bohr model?In accordance with the Bohr model of the atom, We know that electrons could be promoted from the from a lower to a higher energy level. As such, the movement of the electron would lead to the emission of light of a characteristic wavelength.
Hence;
1/λ = 1.097 * 10^7 (1/[tex]n_{2} ^{2}[/tex] - 1/[tex]n_{1} ^{2}[/tex])
Hence;
n1 = 1
n2 = 12
We then have;
1/λ = 1.097 * 10^7 (1/1^2 - 1/12^2)
1/λ = 1.097 * 10^7 (1 - 0.0069)
λ = 9.2 * 10^-8 m or 92 nm
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A scientist uses a graduated cylinder to measure 100.0 mL of gasoline for an experiment. The density of gasoline is 0.774 g/mL. What is the mass of this gasoline sample?
Answer:
100ml x 0.774
divide by 4
x by 8
In the reaction below, if a total of 10.0 g of zinc and hydrochloric acid react completely, what is the total mass of zinc chloride and hydrogen produced?Zn(s) + 2HCl(aq) to ZnCl2(aq) + H2(g)Exactly 10.0 gLess than 10.0 gNot enough information to tellGreater than 10.0 g
Answer:
Not enough information to tell.
Explanation:
What is given?
Mass of Zn = 10.0 g,
Mass of HCl = 10.0 g,
Molar mass of Zn = 65.4 g/mol,
Molar mass of HCl = 36.4 g/mol,
Molar mass of ZnCl2 = 136.2 g/mol,
Molar mass of H2 = 2 g/mol.
Step-by-step solution:
First, let's convert 10.0 g of each reactant to moles using their respective molar mass:
[tex]\begin{gathered} 10.0\text{ g Zn}\cdot\frac{1\text{ mol Zn}}{65.4\text{ g Zn}}=0.153\text{ moles Zn,} \\ \\ 10.0\text{ g HCl}\cdot\frac{1\text{ mol HCl}}{36.4\text{ g HCl}}=0.275\text{ moles HCl.} \end{gathered}[/tex]Now, let's identify what is the limiting reactant. Let's see how many moles of ZnCl2 can be produced by 0.153 moles of Zn if 1 mol of Zn reacted produces 1 mol of ZnCl2, and how many moles of ZnCl2 can be produced by 0.275 moles of HCl if 2 moles of HCl reacted produces 1 mol of ZnCl2:
[tex]\begin{gathered} 0.153\text{ moles Zn}\cdot\frac{1\text{ mol ZnCl}_2}{1\text{ mol Zn}}=0.153\text{ moles ZnCl}_2, \\ \\ 0.275\text{ moles HCl}\cdot\frac{1\text{ mol ZnCl}_2}{2\text{ moles HCl}}=0.138\text{ moles ZnCl}_2. \end{gathered}[/tex]You can realize that the limiting reactant, in this case, is HCl because is the first reactant consumed first and this reactant 'impose' the limit to produce the products.
So now, let's find how many moles of H2 are being produced by 0.275 moles of HCl if 2 moles of HCl reacted produces 1 mol of H2:
[tex]0.275\text{ moles HCl}\cdot\frac{1\text{ mol H}_2}{2\text{ moles HCl}}=0.138\text{ moles H}_2.[/tex]The final step is to convert each number of moles of each product to grams using their respective molar mass, as follows:
[tex]\begin{gathered} 0.138\text{ moles ZnCl}_2\cdot\frac{136.2\text{ g ZnCl}_2}{1\text{ mol ZnCl}_2}=18.8\text{ g ZnCl}_2, \\ \\ 0.138\text{ moles H}_2\cdot\frac{2\text{ g H}_2}{1\text{ mol H}_2}=0.276\text{ g H}_2. \end{gathered}[/tex]We're producing 18.8 g of zinc chloride (ZnCl2), and 0.276 g of hydrogen (H2), so based on this logic the answer would be not enough information to tell.
9. Which of the following shows whose model?a. Bohrb. Daltonc. Rutherfordd. Thomson
Answer
d. Thomson
Explanation
The given model shown above is Thomson's model of an atom.
In 1898, J. J. Thomson proposed that an atom is shaped like a sphere with a radius of approximately 10⁻¹⁰m, where the positive charge is uniformly distributed as shown in the model given. The electrons are embedded in this sphere so as to give the most stable electrostatic arrangement.
Thus, Thomson's model of an atom is also referred to as the watermelon model, the plum pudding model or the raisin pudding model.
An important aspect of Thomson's model of an atom is that it assumes that the mass of the atom is uniformly distributed over the atom. The model was successful in explaining the overall neutrality of the atom.
A reaction between liquid reactants takes place at 28.0 degree celcuis in a sealed, evacuated vessel with a measured volume of 15.0L. Measurements show that the reaction produced 10.0g of dinitrogen difluoride gas.
Calculate the pressure of dinitrogen difluoride gas in the reaction vessel after the reaction. You may ignore the volume of the liquid reactants. Round your answer to 2 significant digits.
The pressure of N2F2 will be 1.64 atm.
Given data:
Mass of N2F2 = 66 grams
Molar mass of N2F2 = 66 g/mol
Temperature = 28°C = 273 +28 = 301 Kelvin
volume = 15 L.
Gas constant = 0.08206 L*atm/K* mol
Number of moles can be determined by using the formula:
Number of moles = mass of N2F2 / Molar mass of N2F2
Number of moles = 66 g/ 66 g/mol = 1 moles.
Volume can be determined by using the formula:
P*V = n×R×T
where, P is pressure, V is volume, T is temperature.
P = (n×R×T)/ V
P = 1 * 0.08206 * 301 )/15 = 1.6466 atm.
The pressure of the sulfur tetrafluoride gas is 1.64 atm.
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Please help with Chemistry I'm confused at the elements reactivity:
Question:
Which of the following combination of elements is the most reactive?
Answer options:
A: Potassium and Iodine
B: Caesium and Iodine
C: Sodium and Bromine
D: Caesium and Bromine
The combination of elements that is the most reactive would be caesium and bromine.
Reactivity of metals and non-metalsThe reactivity series of elements is a table that shows how reactive elements are, usually in descending order.
Elements are classified as metals, non-metals, and metalloids. Metals or non-metals that are at the top of the reactivity series are highly reactive and cannot be displaced in solution by metals below them.
Highly reactive non-metals are also usually at the top of the reactivity series of non-metals. They are able to form compounds with a wide variety of elements.
A typical reactivity series of metals include caesium, rubidium, potassium, sodium, lithium, etc. A reactivity series of non-metals include fluorine, chlorine, oxygen, bromine, iodine, etc.
Thus, bromine is more reactive than iodine and caesium is more reactive than potassium and sodium.
The combination of elements that are the most reactive among the options is, therefore, Caesium and Bromine.
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I dont understand how to find the one with smallest atomic radiusa. Calciumb. Cobaltc. potassiumd NickelI think its last one but why
Answer:
d. Nickel
Explanation:
The atomic radius is a periodic property, that is, we can see how it varies in the Periodic Table of Elements.
Atomic radius increases by a column (group) from top to bottom, and increases by a row (period) from right to left.
We can see the variation of atomic radius and the location of the given atoms in the following drawing:
Since K (potassium), Ca (calcium), Co (cobalt) and Ni (nickel) are located in the same row (period), to identify which one has the smallest atomic radius, we have to analyze the increase in horizontal atomic radius.
So, the Ni atom has the smallest atomic radius (because it is located more to the right compared to the other atoms in the same row) and K atom has the largest atomic radius.
6.5 grams of zinc reacted with hydrochloric acid. Calculate how many grams of hydrogen were released. a) 0.1 g. b) 0.2 g. c) 1.0 g. d) 2.0 g.
0.2 grams
ExplanationsThe balanced reaction between zinc and hydrochloric acid is given as:
[tex]Zn+2HCl\rightarrow ZnCl_2+H_2[/tex]Given the following parameters
Mass of Zinc = 6.5grams
Determine the mole of Zinc
Mole of Zn = mass/molar mass
Mole of Zn = 6.5/65.38
Mole of Zn = 0.0994moles
According to stoichiometry, 1 mole of Zinc produced 1 mole of hydrogen gas, hence the mole of hydrogen gas required will be 0.0994moles
Determine the mass of hydrogen gas produced
[tex]\begin{gathered} Mass\text{ of H}_2=mole\times molar\text{ mass} \\ Mass\text{ of H}_2=0.0944moles\times2.016 \\ Mass\text{ of H}_2=0.19g\approx0.2grams \end{gathered}[/tex]Hence the mass of hydrogen that were released is 0.2 grams
Which of the listed species have the following electron configuration?
(See attached)
Answer:
Al 3+
Na+
Mg2+
F-
Explanation:
The element with the given electron that isn't an ion is Neon. It has 10 electrons in total.
Looking at the periodic table attached will help to see how the elements below are related to the one circled in red (Ne).
Al 3+ lacks 3 (because it has a 3+ charge) of its normal electrons so it has 10 and will have the same electron configuration as shown.
Na+ lacks one electron so it will also have 10 electrons instead of its normal 11.
Mg 2+ lacks two electrons so it will also have 10 total electrons.
F- has gained an extra electron so it now has 10 instead of 9.
Al3+, Na+, F-, and Mg2+ will have the given electronic configuration.
The electronic configuration given in the question is:
2p6, 2s2, 1s2
If it was a stable atom, the answer would have been Neon.
And if that would have been negative ion or anion (to be precise),
the answer would have been either F- or O2-.
But in the case of positive ions or we can say cations,
Al3+, Na+, and Mg2+ have the given electronic configurations.
Because the atom of Aluminum loses three electrons to achieve another state which is responsible for the formation of Al3+.
Similarly,
The atoms of Sodium and Magnesium also lose one and two electrons respectively to form Na+ and Mg2+.
So, we can conclude that Al3+, Na+, F- and Mg2+ will have the given electronic configuration.
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What is the name of the product formed by the reaction of propylide ion and 2-chloropropane?
If 1495 J of heat is needed to raise the temperature of a 315 g sample of a metal from 55.0°C to 66.0°C, what is the specific heat capacity of the metal?
The specific heat capacity of the metal that needs 1495 J of heat to raise the temperature is 0.43J/g°C.
How to calculate specific heat capacity?Specific heat capacity is the heat capacity per unit mass of a substance. It can be calculated by using the following formula:
Q = mc∆T
Where;
Q = quantity of heat absorbed or releasedm = mass of substancec = specific heat capacity∆T = change in temperatureAccording to this question, 1495 J of heat is needed to raise the temperature of a 315 g sample of a metal from 55.0°C to 66.0°C. The specific heat capacity can be calculated as follows;
1495 = 315 × c × {66 - 55}
1495 = 3465c
c = 1495/3465
c = 0.43J/g°C
Therefore, 0.43J/g°C is the specific heat capacity of the metal that requires a heat of 1495J.
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A saturated solution of MgF2 is prepared at 27°C. After equilibrium has been reached, the concentrationof magnesium ions in the solution is found to be 1.2 x 10-3 M. Type in the correct values for A and B inthe ICE table.A:Mg2+(aq)2F (aq)1SolidAMBMB:DONEс-Dissolvedsolid+?M+?MELess solid?M?MIntro
Answer:
A: 0
B: 0
Explanation:
Initially the concentration of Mg+2 ions and F- ions is zero. The ICE table is:
A solution is made by dissolving4.87 g of potassium nitrate in waterto a final volume of 86.4 mL solution.What is the weight/weight % orpercent by mass of the solute?Use 1.00 g/mL for the density of the solution.Enter text here
Answer
The weight/weight % of solute = 5.3%
Explanation
Given
Mass of solute (potassium nitrate) = 4.87 g
Volume of solvent (water) = 86.4 mL
Density of water = 1.00 g/mL
Required: Weight/weight% of the solute
Solution
Step 1: Covert the volume of water to mass
mass = density x volume
mass = 1.00 g/mL x 86.4 mL
mass = 86.4 g
Step 2: Calculate the weight/weight % of the solute
Mass % solute = [mass of solute/(mass of solute + mass of solvent)] x 100
Mass % solute = 4.87g/(4.87 + 86.4)
Mass % solute = 5.3%
2. Oxygen gas is collected at a pressure of 123 kPa in a container which has a volumeof 10.0 L. What temperature must be maintained on 0.654 moles of this gas in order tomaintain this pressure? Express the temperature in Kelvin.
Answer
T = 226.21 K
Explanation
Given:
Pressure = 123 kPa
Volume = 10.0 L
number of moles = 0.654 moles
We know R = 8.314 L kPa/mol k.
Required: Temperature
Solution:
Pv = nRT
T = PV/nR
T = (123 kPa x 10.0 L)/(0.654 mol x 8.314 L kPa/mol k)
T = 226.21 K
Read each question carefully and choose the letter of the best answer.
This element is nonmetal and appears in the periodic table.
The number that represents the position of the elements is called, the atomic number, it also represents the number of protons = numbers of electrons an atom has.
Answer: D. the atomic number
What is kinetic energy related to?
ОА.
heat
OB.
position
O C.
motion
OD. electricity
Kinetic energy refers to the work required to accelerate a body from an initial state of rest to infinite speed. So kinetic energy is related to the motion and speed of a body.
So the answer will be C. motion
Create a table of different types of radioactive decay and the changes that result in each.
answer and explanation
Radioactivity is the emission of ionizing radiation from nuclear decay. there are three types of radioactive decay.
alpha decay
in alpha decay an alpha particle is released. In the parent atom, the atomic number decreases by 2 and the atomic mass decreases by 4
beta decay
in beta decay a beta particle is released, the atomic number is unchanged and the atomic mass increases by 1
gamma decay
in gamma decay, energy is released as gamma rays from an excited nuclear state. the atomic mass and atomic number remain unchanged.
a sample of a gas is at STP and it’s temperature remains constant. if the pressure decreases what will happen to the volume
Explanation
There are said to have two different conditions of a gas.
First condition is STP which means: pressure = 1 atm and temperature (absolute) = 0 °C + 273 = 273 K
-------------
It is said that the temperature remains constant, therefore we can apply Boyle's law which states that the pressure of a gas tends to decrease as the volume of the container increases.
Farmers use primarily two fertilizers - ammonium nitrate and ammonium phospate. Which contains a greater percentage of nitrogen by mass? Write the formula for ammonium nitrate:-----------------------------------------------------------||________________________________First, let's add up the total molar mass of ammonium nitrate below:-----------------------------------------------------------||________________________________Now, let's calculate the percentage of nitrogen in ammonium nitrate:-----------------------------------------------------------||________________________________Now, let's write the formula for ammonium phosphate:-----------------------------------------||______________________First, let's add up the total molar mass of ammonium phosphate below:-----------------------------------------------------------||________________________________Now, let's calculate the percentage of nitrogen in ammonium phosphate:-----------------------------------------------------------||________________________________Which contains a greater percentage of nitrogen by mass?
The nitrogen in ammonium nitrate contains a greater percentage of nitrogen by mass
Explanations:The formula for ammonium nitrate is given as NH4NO3.
Determine the molar mass of NH4NO3
Molar mass = 14 + 4(1) + 14 + 3(16)
Molar mass .= 14 + 4 + 14 + 48
Molar mass of NH4NO3 = 80g/mol
Determine the percentage of nitrogen in the compound
%N = 28/80 * 100
%N = 35%
The formula for ammonium phosphate is (NH4)3PO4
Determine the molar mass of (NH4)3PO4
Molar mass = 3(14) + 4(3) + 4(16) + 3(31)
Molar mass = 42 + 12 + 64 + 31
Molar 1ass = 149g/mol
Determine the percentage of nitrogen in ammonium phosphate:
%N = 42/149 * 100
%N = 28.18%
Hence the nitrogen in ammonium nitrate contains a greater percentage of nitrogen by mass
