Answer:
78.3 × 10²³ atoms of helium are present in 52 g.
Explanation:
Given data:
Mass of He = 52 g
Number of atoms = ?
Solution:
First of all we will calculate the number of moles of He
Number of moles = mass /molar mass
Number of moles = 52 g/ 4 g/mol
Number of moles = 13 mol
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
1 mole = 6.022 × 10²³ atoms of helium
13 mol × 6.022 × 10²³ atoms of helium / 1 mole
78.3 × 10²³ atoms of helium
explain why the first ionization energy of tellurium is greater than that of selenium
The first ionization energy of tellurium is greater than that of selenium due to increased effective nuclear charge and larger atomic size.
The first ionization energy of tellurium is greater than that of selenium due to the increased effective nuclear charge and larger atomic size of tellurium. Tellurium has more protons in its nucleus compared to selenium, resulting in a stronger attraction between the protons in the nucleus and the electrons in the outermost energy level.
This increased attraction requires more energy to remove an electron from the atom, thus resulting in a higher first ionization energy for tellurium. Additionally, tellurium has a larger atomic size, which leads to a greater distance between the outermost electrons and the nucleus. This larger distance reduces the effective nuclear charge felt by the outermost electrons, making it slightly easier to remove an electron compared to selenium. However, the effect of increased effective nuclear charge in tellurium outweighs the influence of atomic size, resulting in a higher first ionization energy for tellurium.
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write expressions for the reaction rate in terms of the rates of change in the concentrations of the reactant and each product with time.
Answer: Rate of change in the concentration of the reactants = -(1/α)* (ΔX/Δt)=-(1/β)(ΔB/Δt)
Explanation: Consider the following reaction:
α X + β B → γ Y + δ D
Then the rate of change in the concentration of reaction = -(1/α)* (ΔX/Δt)=
-(1/β)(ΔB/Δt)
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54.5 mL of liquid gallium metal is poured into a graduated cylinder. The gallium filling the graduated cylinder weighs 10.686 g. From this information, calculate the density of the liquid gallium.
Answer:
The answer is 0.20 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question
mass = 10.686 g
volume of liquid gallium = 54.5 mL
So we have
[tex]density = \frac{10.686}{54.5} \\ = 0.1960733944...[/tex]
We have the final answer as
0.20 g/mLHope this helps you
1 point
Thermal energy is due to the movement of molecules and the heat they
produce. Thermal energy is therefore
potential energy
kinetic energy
none of the above
Once a chemical reaction has reached equilibrium which of the following statements is true? The mass of the products is equal to the mass of the reactants The forward reaction has reached completion The reverse reaction has reached completion All of these statements are true None of these statements are true The forward reaction rate is equal to the reverse reaction rate
The correct statement is: The forward reaction rate is equal to the reverse reaction rate.
At equilibrium, the forward and reverse reactions are still occurring, but their rates become equal. This means that the rate at which reactants are being converted into products in the forward direction is equal to the rate at which products are being converted back into reactants in the reverse direction. As a result, there is no net change in the concentrations of the reactants and products over time. However, it is important to note that equilibrium does not imply that the mass of the products is equal to the mass of the reactants. The equilibrium position depends on the relative concentrations of reactants and products, which may not necessarily be equal in terms of mass.
Additionally, equilibrium does not indicate that either the forward or the reverse reaction has reached completion. Instead, it signifies a dynamic state where the rates of the forward and reverse reactions are balanced.
In summary, at equilibrium, the forward and reverse reactions continue to occur, but their rates are equal, resulting in a constant concentration of reactants and products over time.
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What are the differences between a hypothesis, a theory, and a scientific law? Which has the greatest degree of certainty?
Answer:
Scientific law
Explanation:
Because its based on experiments or observations, that describe or predict a range of natural phenomena.
A hypothesis is a limited explanation of a phenomenon;a scientific theory is an in-depth explanation of the observed phenomenon.
an aqueous solution of h2s is named group of answer choices hydrosulfuric acid. hydrosulfurous acid. sulfuric acid. sulfurous acid.
The correct name for an aqueous solution of [tex]H_2S[/tex] is hydrosulfuric acid. Option A
Hydrosulfuric acid is formed when hydrogen sulfide ([tex]H_2S[/tex]) dissolves in water ([tex]H_2O[/tex]). The formula for hydrosulfuric acid is [tex]H_2S[/tex](aq). It is an acid because it donates a hydrogen ion (H+) when dissolved in water.
Option A: Hydrosulfuric acid is the correct name for [tex]H_2S[/tex]in an aqueous solution. It accurately reflects the composition of the compound and its acidic properties.
Option B: Hydrosulfurous acid is incorrect. It refers to a different compound, which is formed when sulfur dioxide ([tex]SO_2[/tex]) dissolves in water. The formula for hydrosulfurous acid is [tex]H_2SO_3[/tex].
Option C: Sulfuric acid is incorrect. Sulfuric acid has the chemical formula [tex]H_2SO_4[/tex], and it is not the same as hydrosulfuric acid ([tex]H_2S[/tex]).
Option D: Sulfurous acid is also incorrect. Sulfurous acid has the chemical formula [tex]H_2SO_3[/tex], and it is different from hydrosulfuric acid ([tex]H_2S[/tex]).
Option A
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A student measures the volume of acid three times and the reading
come out to be 27.25 ml, 27.38 ml, and 27.42 ml respectively. But the
actual volume of acid is 27.34 ml. Hence the measurements taken by
the student are precise as well as accurate. True or false
Answer:
True
Explanation:
A hose delivers water to a swimming pool that measures 9.0 m long by 3.5 m wide by 1.75 m
deep. It requires 97 hours to fill the pool. At what rate in liters/min (1/min) will the hose fill the
pool.
Answer: 48.5 hours
Explanation:
Answer:
The answer is 9.47164 the decimal goes on but I think that is enough places.
Explanation:
First, you have to find the area of the pool 9*3.5*1.75= 55.125 meters
Then convert meters to liters to get 55125 liters.
Then you take 55125 liters and put it over min. EX 55125/min
to get minutes you multiply the hours by 60 to get 5820 minutes.
this allowes you to put 55125/5820 then it is a division problem.
The problem after dividing geves you 9.47164......
When calculating the number of neutrons an element has, you can
A: copy the atomic number from the periodic table
B: atomic mass subtracted from atomic number
C: copy the number of electrons
D: copy the atomic mass from a periodic table
Answer:
B: atomic mass subtracted from the atomic number.
Explanation:
In order to calculate the number of neutrons an element has, one must take the atomic mass for the element and subtract it from the atomic number.
Draw Molecular diagrams of solid, liquid, gas and plasma phases of matter.
Answer:
Explanation:
Hope this helped!
List the kinds of structures, similar to a business or factory, that a cell must have to operate successfully.
Answer:
1. Chief executive officer = Nucleus.
2. Power house = Mitochondrion.
3. Maintenance team = Lysosomes.
4. Functional managers = Chromosomes.
5. Assembly line workers = Ribosomes.
6. Assembly line = Endoplasmic Reticulum.
7. Security and support = Cytoskeleton.
8. Drivers or messengers = Vesicles.
9. Packaging unit = Golgi apparatus.
10. Gate man/procurement unit = Cell membrane.
Explanation:
A cell can be defined as the structural, fundamental, biological and functional unit of life. Cells are found in all living organisms because they are the basic unit of life.
Generally, cells have the ability to independently replicate themselves. These cells can be compared to the kind of structures found in a business or factory, where you have different workers performing different functions.
In a cell, the "workers" that perform various functions or tasks for the survival of the living organism are referred to as organelles.
Factory worker = Cell organelle.
1. Chief executive officer = Nucleus.
The nucleus controls all the activities taking place in the cell and the synthesis of proteins.2. Power house = Mitochondrion.
The mitochondria provides all the energy required in the cell by transforming energy forms.3. Maintenance team = Lysosomes.
They are responsible for absorbing materials and breaking the materials taken in by the cells.4. Functional managers = Chromosomes.
They give sets of instructions for the synthesis of products.5. Assembly line workers = Ribosomes.
They are involved in the build up of proteins.6. Assembly line = Endoplasmic Reticulum.
This is where the ribosomes perform their tasks.7. Security and support = Cytoskeleton.
They help to maintain and support the shape of the cells.8. Drivers or messengers = Vesicles.
They ensure proteins are properly transported to the right and exact location.9. Packaging unit = Golgi apparatus.
Prepares the protein for export by chemically tagging them.10. Gate man/procurement unit = Cell membrane.
It is the wall of the cell and typically controls what leaves and enters the cell.A. Water moving into the root cells of a plant
B. Oxygen moving into the bloodstream from
the lungs
C. Potassium ions moving in and out of an
animal cell
D. All of the above
Answer:
c
Explanation:
because it has potassium
Which of the following will require the least time for a reaction to reach equilibrium? O a. Cannot tell, since the time required to reach equilibrium does not depend on Kc. O b. Cannot tell without knowing the value of Kc- O c. Kc is a very large number. O d. Kc is a very small number. O e. Kc is approximately one.
The time required for a reaction to reach equilibrium can depend on the value of Kc, which represents the equilibrium constant. The equilibrium constant, Kc, is determined by the concentrations of the reactants and products at equilibrium.
In general, reactions with a larger Kc value tend to reach equilibrium more quickly than those with a smaller Kc value. This is because a larger Kc indicates that the concentration of products is higher compared to the concentration of reactants at equilibrium. As a result, the reaction proceeds more rapidly to reach the point where the ratio of products to reactants matches the value of Kc.
Therefore, among the given options, the answer would be option (c) where Kc is a very large number. In this case, the reaction would require the least amount of time to reach equilibrium.
It's important to note that the actual time required for a reaction to reach equilibrium depends on various factors such as temperature, pressure, and the presence of catalysts. Additionally, the time required for a reaction to reach equilibrium cannot be determined solely based on the value of Kc. However, in general, a larger Kc value suggests a quicker attainment of equilibrium.
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the experimentally determined atomic mass of mg-26 is 25.98259 amu. calculate the mass defect, the binding energy in j/mol the binding energy in mev/atom.
the mass defect is 26.436832 amu, the binding energy is 6.53220238 x 10¹² J/mol, and the binding energy is 4.0771637 x 10⁴ MeV/atom for Mg-26.
To calculate the mass defect, binding energy in joules per mole (J/mol), and binding energy in mega-electron volts per atom (MeV/atom), we need to use Einstein's mass-energy equivalence equation, E = mc².
The mass defect (Δm) can be calculated by subtracting the experimentally determined atomic mass (m) of Mg-26 from its nominal mass (m0), which can be calculated by summing the masses of individual protons, neutrons, and electrons.
The binding energy (E) can be calculated by multiplying the mass defect by the speed of light squared (c²). Then, the binding energy in J/mol can be obtained by dividing the binding energy by Avogadro's constant (NA). Finally, the binding energy in MeV/atom can be obtained by dividing the binding energy in J/mol by the conversion factor 1.6022 x 10⁻¹³.
Given:
Experimental atomic mass of Mg-26 (m) = 25.98259 amu
To calculate the nominal mass (m0) of Mg-26, we can refer to the atomic mass of individual particles:
Proton mass = 1.007276 amu
Neutron mass = 1.008665 amu
Electron mass = 0.000548597 amu
Nominal mass (m0) of Mg-26 = (26 protons * proton mass) + (26 neutrons * neutron mass) + (26 electrons * electron mass)
Let's calculate the values:
m0 = (26 * 1.007276) + (26 * 1.008665) + (26 * 0.000548597)
= 26.185776 + 26.21939 + 0.014256622
= 52.419422 amu
Now we can calculate the mass defect (Δm):
Δm = m0 - m
= 52.419422 - 25.98259
= 26.436832 amu
To calculate the binding energy in J/mol:
E = Δm * c²
First, we need to convert amu to kg (kilograms). The conversion factor is:
1 amu = 1.66053906660 x 10⁻²⁷ kg
Converting the mass defect to kilograms:
Δ[tex]m_{kg}[/tex] = Δm * (1.66053906660 x 10⁻²⁷)
= 26.436832 * (1.66053906660 x 10⁻²⁷)
= 4.3811076256 x 10⁻²⁶ kg
Next, we need to calculate the binding energy (E) in joules:
E = Δ[tex]m_{kg}[/tex] * c²
The speed of light, c = 2.998 x 10⁸ m/s
E = (4.3811076256 x 10⁻²⁶ kg) * (2.998 x 10⁸ m/s)²
= 3.93766794178 x 10⁻¹¹ J
To calculate the binding energy in J/mol, we divide E by Avogadro's constant (NA):
NA = 6.02214076 x 10²³ mol⁻¹ (Avogadro's constant)
Binding energy in J/mol = E / NA
= (3.93766794178 x 10⁻¹¹ J) / (6.02214076 x 10²³ mol⁻¹)
= 6.53220238 x 10¹² J/mol
Finally, to calculate the
binding energy in MeV/atom, we divide the binding energy in J/mol by the conversion factor 1.6022 x 10⁻¹³:
Binding energy in MeV/atom = (6.53220238 x 10¹² J/mol) / (1.6022 x 10⁻¹³ J/MeV)
= 4.0771637 x 10⁴ MeV/atom
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what mass (in grams) of mg(no3)2 is present in 146 ml of a 0.150 m solution of mg(no3)2 ? what mass (in grams) of is present in 146 of a 0.150 solution of ?1.89 g 0.0219 g 144 g 3.25 g
Given: Volume (V) = 146 mL, Molarity (M) = 0.150 M, Molar mass of Mg(NO₃)₂ = 148.31 g/molTo find: mass (in grams) of Mg(NO₃)₂Presently, we have Molarity of Mg(NO₃)₂ .i.e., 0.150 M = 0.150 mol/L .
Now, we need to convert the volume from mL to L by dividing the volume by 1000 as shown below;
Volume (V) = 146 mL = 146/1000 L = 0.146 L.
Now, we can use the following formula to find the number of moles of solute (Mg(NO₃)₂) :Number of moles (n) = Molarity (M) × Volume (V)
Putting values in the above equation, we get:
Number of moles (n) = 0.150 mol/L × 0.146 L
= 0.0219 mol
Now, we can use the molar mass formula to find the mass of Mg(NO₃)₂ ; Molar mass (M) of Mg(NO₃)₂ = 148.31 g/mol
Mass (m) = Number of moles (n) × Molar mass (M)
Putting values in the above equation, we get;
Mass (m) = 0.0219 mol × 148.31 g/mol = 3.25 g.
Hence, the main answer is 3.25 grams.
Therefore, the mass (in grams) of Mg(NO₃)₂ present in 146 ml of a 0.150 M solution of Mg(NO₃)₂ is 3.25 grams.
From the above solution, we can conclude that we need to find the mass (in grams) of Mg(NO₃)₂ which is present in 146 mL of a 0.150 M solution of Mg(NO₃)₂.
We have used the formula of Molarity to find the number of moles of Mg(NO₃)₂. We have also converted the given volume from milliliters (mL) to liters (L).
We have used the molar mass formula to find the mass of Mg(NO₃)₂ .i.e., the product of number of moles and molar mass of Mg(NO₃)₂. The Molar mass of Mg(NO₃)₂ is 148.31 g/mol. We have substituted the given values in the above formulas and solved the problem. The final answer is 3.25 grams.
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In the water cycle, clouds form as a result of _____?
Answer:
Hello,
Clouds form as a result of condensation.
Explanation:
The definition of condensation is, 'the conversion of a vapor or gas to a liquid.'
Answer:
condensation.
Explanation:
the temperature of a 11.8 g sample of calcium carbonate [caco3 (s)] increases from to if the specific heat of calcium carbonate is how many joules of heat are absorbed? group of answer choices -0.92 j -130 j 11 j 130 j 0.92 j
130 Joules of heat is absorbed when the temperature of a 11.8 g sample of calcium carbonate [caco3 (s)] increases from to if the specific heat of calcium carbonate.
To solve the given problem, we will use the formula:q = mcΔTwhere q is the heat absorbed by the substance, m is the mass of the substance, c is the specific heat of the substance, and ΔT is the change in temperature of the substance.We are given:m = 11.8 gΔT = 41.8 °C - 22.7 °C = 19.1 °Cc = 0.82 J/g·°CSubstitute the given values into the formula and solve for q:q = (11.8 g)(0.82 J/g·°C)(19.1 °C)= 130 JTherefore, 130 joules of heat are absorbed by the substance.
The correct option is D which is 130 J.
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If a piece of lead has a volume of 19
mL, what is its mass?
Answer:
The mass of lead is 216.6 g.
Explanation:
Given data:
Volume of lead = 19 mL
Mass of lead = ?
Solution:
To solve this problem we will apply the density formula.
In literature density of lead is 11.4 g/mL.
Density:
Density is equal to the mass of substance divided by its volume.
Units:
SI unit of density is Kg/m3.
Other units are given below,
g/cm3, g/mL , kg/L
Formula:
D=m/v
Now we will put the values.
11.4 g/mL = m/ 19 mL
m = 11.4 g/mL×19 mL
m = 216.6 g
The mass of lead is 216.6 g.
In making wine, glucose (C6H12O6) is fermented to produce ethanol (C2H5OH) and carbon dioxide (CO2), according to the following reaction.
C6H12O6 → 2 C2H5OH + 2 CO2
(a) If the fermentation reaction starts with 71.0 g glucose, what is the theoretical yield of ethanol (in grams)? i need the correct number of sig figs also
(b) If 24.0 g ethanol is produced, what is the percent yield of this reaction? i need the correct number of sigfigs also.
Molar mass of ethanol (C2H5OH) = 46.07 g/mol . To find the theoretical yield of ethanol, we need to calculate the stoichiometric ratio between glucose and ethanol in the given reaction.
Given that the balanced equation for the fermentation of glucose to ethanol is:
C6H12O6 → 2 C2H5OH + 2 CO2
From the balanced equation, we can see that the stoichiometric ratio between glucose and ethanol is 1:2. This means that for every mole of glucose, we should theoretically produce 2 moles of ethanol.
(a) To calculate the theoretical yield of ethanol, we need to convert the mass of glucose to moles and then use the stoichiometric ratio to determine the moles of ethanol produced. Finally, we can convert the moles of ethanol back to grams.
Calculate the moles of glucose:
Molar mass of glucose (C6H12O6) = 180.16 g/mol
Moles of glucose = Mass of glucose / Molar mass of glucose
Moles of glucose = 71.0 g / 180.16 g/mol
Use the stoichiometric ratio to determine moles of ethanol:
Moles of ethanol = Moles of glucose × (2 moles of ethanol / 1 mole of glucose)
Convert moles of ethanol to grams:
Mass of ethanol = Moles of ethanol × Molar mass of ethanol
Molar mass of ethanol (C2H5OH) = 46.07 g/mol
(b) To calculate the percent yield, we need to compare the actual yield of ethanol to the theoretical yield.
Given that the actual yield of ethanol is 24.0 g, we can calculate the percent yield using the formula:
Percent yield = (Actual yield / Theoretical yield) × 100%
Substitute the values into the formula and calculate the percent yield.
It's important to note that the accuracy of the percent yield calculation depends on the reliability of the experimental measurement of the actual yield. Factors such as experimental errors, side reactions, and incomplete reactions can affect the actual yield and, consequently, the percent yield obtained.
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Question 1
1 pts
What is it called when more than one element is combined, but do not loose their individual chemical properties?
Answer:
if I'm not mistaken, it is called a mixture
Answer:
mixture
Explanation:
an aquesous soulution at 25 c has a poh of 12.48 calculate the pH. Round your answer to 2 decimal places
___________
The pH of the aqueous solution is 1.52, which suggests a highly acidic nature.
The pOH of an aqueous solution is given as 12.48. To calculate the pH, we can use the relationship between pH and pOH, which states that pH + pOH = 14. Therefore, we can find the pH by subtracting the pOH from 14. To calculate the pH from the pOH value, we can use the relationship pH + pOH = 14, which holds true for any aqueous solution at 25°C. In this case, we are given the pOH value of 12.48. Substituting the given value into the equation, we have pH + 12.48 = 14. To find the pH, we need to isolate it on one side of the equation. Subtracting 12.48 from both sides, we get pH = 14 - 12.48 = 1.52.
Therefore, the pH of the aqueous solution is 1.52. The pH scale is a logarithmic scale that measures the acidity or basicity of a solution. A pH value below 7 indicates acidity, while a pH value above 7 indicates alkalinity. A pH of 1.52 indicates a strongly acidic solution.
In summary, the pH of the aqueous solution is 1.52, which suggests a highly acidic nature. This information is valuable in understanding the properties and behavior of the solution, as acidity or alkalinity can influence chemical reactions, biological processes, and the overall behavior of substances dissolved in the solution.
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how many moles of h20 are needed to produce 55.7 moles of h2
To produce 55.7 moles of H2, an equal number of moles of H2O is required. Therefore, 55.7 moles of H2O are needed.
The balanced chemical equation for the reaction in which H2 is produced from H2O is:
2H2O → 2H2 + O2
According to the stoichiometry of the equation, for every 2 moles of H2O, 2 moles of H2 are produced. This means that the mole ratio of H2O to H2 is 2:2, or simply 1:1.
Given that 55.7 moles of H2 are needed, the same number of moles of H2O is required. Therefore, 55.7 moles of H2O are needed to produce 55.7 moles of H2. The mole ratio of the reactants directly translates to the number of moles needed to obtain a certain amount of product in a stoichiometrically balanced equation.
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Explain, using the kinetic theory, what happens
to the particles in oxygen as it is cooled down,
The kinetic theory states the movement of the molecules in a matter. The particles of oxygen at low temperatures slow down and losses their kinetic energy.
What is the kinetic theory?The kinetic theory states the motion and speed of the molecule of a matter. The theory states about the molecules separated by distance moving in a random motion that is constant.
The particles of the matter collide elastically with each other and this speed and collision depend on the temperature and pressure applied. The kinetic energy is directly dependent on the temperature.
As the temperature of oxygen gas decreases the collision and the speed of the particles also reduce resulting in less kinetic energy. It also leads to a drop in pressure.
Therefore, at low temperatures, kinetic energy, collision, and speed decrease.
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how do batteries use of electron affinity to work?
Answer:
Unlike electronegativity, the electron affinity does not have a strong periodic value. The electron affinity measures the energy released when an electron is captured by the atom (or a molecule), forming an anion with a 1− charge.
Explanation:
If the unknown liquid in letter e has a volume of 5.0mL and a mass of 1.95g, what is its density? Make sure to show all work, use significant figures, and include the final unit. Will the sample float or sink in water?
Answer: Density is 0.39g/ml and will float
Explanation:
Density is mass/volume : 1.95g/5.0ml = 0.39g/ml
This sample will float on water because a object with a density less than 1g/cm3 will float. 1 cubic centimeter equal 1 ml.
"The standard enthalpies of formation of ions in aqueous solution are obtained by arbitrarily assigning a value of zero to H+ ions; that is, ΔFH [H^+(aq)] = 0. (a) For the following reaction, HCl(g) → H+(aq) + C1^-(aq) AH = ΔrH = - 74.9 kJ mol calculate the value of AfHº for the C1 ions. (b) The standard enthalpy of neutralization between a HCI solution and a NaOH solution is found to be - 56.2 kJ mol-1. Calculate the standard enthalpy of formation of the hydroxide ion at 25°C.
a) the standard enthalpy of formation for the Cl- ions is -149.8 kJ/mol. b) the standard enthalpy of formation for the hydroxide ion (OH-) at 25°C is -342.0 kJ/mol.
(a) To calculate the standard enthalpy of formation (ΔfH°) for the Cl- ions, we can use the given information about the reaction enthalpy (ΔrH°) for the formation of H+ and Cl- ions from gaseous HCl.
The reaction is: HCl(g) → H+(aq) + Cl-(aq)
Since the enthalpy change (ΔrH°) for the reaction is given as -74.9 kJ/mol, it represents the sum of the standard enthalpies of formation for the products minus the standard enthalpy of formation for the reactant.
ΔrH° = ΣΔfH°(products) - ΔfH°(reactant)
For this reaction, the reactant is HCl(g), and the products are H+(aq) and Cl-(aq). The standard enthalpy of formation for H+(aq) is given as 0, so we can rewrite the equation as:
-74.9 kJ/mol = ΔfH°(H+(aq)) + ΔfH°(Cl-(aq)) - ΔfH°(HCl(g))
Plugging in the known values, we get:
-74.9 kJ/mol = 0 + ΔfH°(Cl-(aq)) - ΔfH°(HCl(g))
Since we want to find the standard enthalpy of formation for Cl-(aq), we isolate ΔfH°(Cl-(aq)):
ΔfH°(Cl-(aq)) = -74.9 kJ/mol + ΔfH°(HCl(g))
Substituting the given value of ΔrH° for the reaction:
ΔfH°(Cl-(aq)) = -74.9 kJ/mol + (-74.9 kJ/mol)
Simplifying the expression, we find:
ΔfH°(Cl-(aq)) = -149.8 kJ/mol
(b) To calculate the standard enthalpy of formation (ΔfH°) of the hydroxide ion (OH-) at 25°C, we can use the information about the standard enthalpy of neutralization (ΔH°n) between HCI and NaOH.
The neutralization reaction between HCI and NaOH is:
H+(aq) + OH-(aq) → H2O(l)
The enthalpy change for this reaction, ΔH°n, is given as -56.2 kJ/mol.
The standard enthalpy of formation of water (H2O) is -285.8 kJ/mol. Using this information, we can rewrite the equation as:
ΔH°n = ΣΔfH°(products) - ΣΔfH°(reactants)
-56.2 kJ/mol = 0 + ΔfH°(OH-(aq)) - (-285.8 kJ/mol)
Simplifying the expression, we find:
-56.2 kJ/mol = ΔfH°(OH-(aq)) + 285.8 kJ/mol
ΔfH°(OH-(aq)) = -56.2 kJ/mol - 285.8 kJ/mol
ΔfH°(OH-(aq)) = -342.0 kJ/mol
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The liquid phase reaction A + B —r C occurs in an isothermal. continuously stirred batch reactor. Given that the initial concentration of A is 80 1nol.-"'1n3 and the initial concentration of B is 8'0 1nol.-"'1n3, what. is the reaction time needed to achieve 95% conversion of the limiting,T reactant" The reaction is first order in A and B and the second order rate constant is LOE-«i 1n3..-"'1nol..-"'s.
The reaction time needed to achieve 95% conversion of the limiting reactant is approximately 46.05 seconds.
To find the reaction time needed to achieve 95% conversion of the limiting reactant in an isothermal continuously stirred batch reactor, we need to use the first order rate equation:
ln(C₀/C) = kt
Where:
- C₀ is the initial concentration of the reactant
- C is the concentration of the reactant at a given time t
- k is the rate constant of the reaction
- t is the reaction time
In this case, the reaction is first order in both reactants, A and B. So, we need to consider the reactant with the lowest initial concentration as the limiting reactant.
Given:
Initial concentration of A (C₀,A) = 80 mol/L
Initial concentration of B (C₀,B) = 80 mol/L
Since both A and B are present in equal amounts initially, we can consider either A or B as the limiting reactant. Let's assume A is the limiting reactant.
To achieve 95% conversion of A, we need to find the concentration of A at that point, which is (5/100) times the initial concentration of A:
C = (5/100) * C₀,A
Now, substituting the values in the first order rate equation, we get:
ln(C₀,A/C) = k * t
Rearranging the equation, we have:
t = ln(C₀,A/C) / k
Substituting the values given in the problem:
C₀,A = 80 mol/L
C = (5/100) * C₀,A = (5/100) * 80 mol/L = 4 mol/L
k = 1E-3 L/mol/s
Calculating the reaction time:
t = ln(80/4) / (1E-3)
Simplifying the expression:
t = ln(20) / (1E-3)
Using a calculator, we find:
t ≈ 46.05 s
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the chemical reaction of adding an acid to a base yields salt and water is known as____
The chemical reaction of adding an acid to a base yields salt and water is known as a neutralization reaction.
A neutralization reaction is a chemical reaction that occurs when an acid and a base are combined to produce water and a salt. The reaction involves the transfer of protons from an acid to a base, resulting in the formation of water and an ionic compound (a salt).This type of reaction occurs when a strong acid is mixed with a strong base, producing a neutral solution. Water and a salt are produced during this process, and the pH of the solution is close to 7.
For example, HCl + NaOH → NaCl + H2O.
Neutralization reactions are important in many different fields, including chemistry, biology, and medicine. In chemistry, neutralization reactions are used to prepare salts, which are used in a variety of applications. In biology, neutralization reactions are involved in many important processes, such as digestion and the immune system. In medicine, neutralization reactions are used to treat acidosis, a condition in which the blood is too acidic.
Acids are substances that produce hydrogen ions (H+) when dissolved in water. They have a sour taste and can burn skin and other materials. Examples of acids include hydrochloric acid, sulfuric acid, and acetic acid.
A base is a substance that produces hydroxide ions (OH-) when dissolved in water. They have a bitter taste and feel slippery to the touch. Examples of bases include sodium hydroxide, potassium hydroxide, and calcium hydroxide.
Thus, the chemical reaction of adding an acid to a base that yields salt and water is known as a neutralization reaction.
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An apple has a mass of 1.2 hectograms. What is the mass of the
apple in grams?
Help me plz.
Answer:
It's 120 g
Explanation:
I'm doing that question on ck12 and it's correct.
