Question 1

The heat of solution of NH₄NO₃ is 26.2 kJ/mol. Is heat evolved or absorbed when a solution of NH₄NO₃ is diluted by addition of more water?

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Question 2

The heat of solution of calcium chloride CaCl₂ is -82.8 kJ/mol, and the combined heats of hydration of 1 mole of gaseous calcium ions and 2 mole of gaseous chloride ions is -2327 kJ.What is the lattice energy of calcium chloride?

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Question 3

A 0.1946 g piece of magnesium metal is burned in a constant-volume calorimeter that has a heat capacity of 1349 J/°C. The calorimeter contains 500.g of water and the temperature rise is 1.40°C. Calculate the heat of combustion of magnesium metal in kJ/g, given that the specific heat of water = 4.184 J/g·°C.

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Question 4

Find $\Delta$H°_rxn for the reaction 2Ag₂S(s)+ 2H₂O(l)$\rarr$ 4Ag(s)+ 2H₂S(g)+ O₂(g). [$\Delta$H°_f (Ag₂S(s))= -32.6 kJ/mol; $\Delta$H°_f (H₂S(g))= -20.5 kJ/mol; $\Delta$H°_f (H₂O(l))= -285.5 kJ/mol]

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Question 5

What is the standard enthalpy of formation of H₂(g)at 25°C?

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Question 6

When an automobile engine starts, the metal parts immediately begin to absorb heat released during the combustion of gasoline. How much heat will be absorbed by a 165 kg iron engine block as the temperature rises from 15.7°C to 95.7°C? (The specific heat of iron is 0.489 J/g·°C.)

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Question 7

The heat of combustion of propane, C₃H₈, 2220 kJ/mol.The specific heat of copper is 0.385 J/g.°C.How many grams of propane must be burned to raise the temperature of a 10.0 kg block of copper from 25.0°C to 65.0°C, assuming none of the heat is lost to the surroundings

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Question 8

The residential rate for natural gas is about $15 per thousand cubic foot.Burning one cubic foot of natural gas releases about 1080 kJ of heat.How much would it cost to heat the water in a 25,000 gallon swimming pool from 52°F to 78°F, assuming all of the heat from burning the natural gas went towards warming the water? (1 gal = 3.785 L; the specific heat of water = 4.184 J/g·°C)

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Question 9

At body temperature 2,404 joules of energy are required to evaporate 1.00 g of water.After vigorous exercise, a person feels chilly because the body is giving up heat to evaporate the perspiration.A typical person perspires 25 mL of water after 20.minutes of exercise.How much body heat is this person using to evaporate this water?

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Question 10

The heat of neutralization of HCl by NaOH is $\Delta$H°_rxn = -56.2 kJ/mol. How much heat is released when 125 mL of 1.750 M HCl is mixed with 195 mL of 0.667 M NaOH?

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Question 11

A 0.3423 g sample of pentane, C₅H₁₂, was burned in a bomb calorimeter. The temperature of the calorimeter and the 1.000 kg of water contained therein rose from 20.22°C to 22.82°C. The heat capacity of the calorimeter is 2.21 kJ/°C.The heat capacity of water = 4.184 J/g·°C. How much heat was given off during combustion of the sample of pentane?

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Question 12

The specific heat of silver is 0.235 J/g·°C. How many joules of heat are required to heat a 75 g silver spoon from 20°C to 35°C?

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Question 13

The heat released when one mole of water is formed from the elements is 1,198 kJ. An experiment was conducted that permitted water to form in this manner, and the heat was contained in 2.0 liters of water.The water temperature before the reaction was 34.5°C, and after the reaction it had risen to 52.0°C. How many moles of water were formed? (The specific heat of water is 4.184 J/g·°C.)

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Question 14

A 0.3423 g sample of pentane, C₅H₁₂, was burned in a bomb calorimeter. The temperature of the calorimeter and the 1.000 kg of water contained therein rose from 20.22°C to 22.82°C. The heat capacity of the calorimeter is 2.21 kJ/°C.The heat capacity of water = 4.184 J/g·°C. What is the heat of combustion, in megajoules (MJ), per mole of pentane?

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Question 15

A 0.3423 g sample of pentane, C₅H₁₂, was burned in a bomb calorimeter. The temperature of the calorimeter and the 1.000 kg of water contained therein rose from 20.22°C to 22.82°C. The heat capacity of the calorimeter is 2.21 kJ/°C.The heat capacity of water = 4.184 J/g·°C. What is the heat of combustion, in kilojoules, per gram of pentane?

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Question 16

Find $\Delta$H°_rxn for the reaction 2Na(s)+ 2H₂O(l)$\rarr$ 2NaOH(aq)+ 2H₂(g). [$\Delta$H°_f (NaOH(aq))= -426.8 kJ/mol; $\Delta$H°_f (H₂O(l))= -285.5 kJ/mol]

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Question 17

Find $\Delta$H°_rxn for the reaction CH₄(g)+ 2O₂(g)$\rarr$CO₂(g)+ 2H₂O(l). [$\Delta$H°_f (CH₄(g))= -74.8 kJ/mol; $\Delta$H°_f (CO₂(g))= -393.5 kJ/mol; $\Delta$H°_f (H₂O(l))= -285.5 kJ/mol]

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Question 18

The value of $\Delta$H°_rxn for the following reaction is -6535 kJ/mol. 2C₆H₆(l)+ 15O₂(g)$\rarr$12CO₂(g)+ 6H₂O(g) How many kilojoules of heat will be evolved during the combustion of 16.0 g of C₆H₆(l)?

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Question 19

A 26.2 g piece of copper metal is heated from 21.5°C to 201.6°C. Calculate the amount of heat absorbed by the metal. The specific heat of Cu is 0.385 J/g·°C.

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Question 20

What would be the standard enthalpy change for the reaction of one mole of H₂(g)with one mole of Cl₂(g)to produce two moles of HCl(g)at standard state conditions? [$\Delta$H°_f (HCl(g))= -92.3 kJ/mol]

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Quiz 6: Thermo-Chemistry

The heat of solution of NH₄NO₃ is 26.2 kJ/mol. Is heat evolved or absorbed when a solution of NH₄NO₃ is diluted by addition of more water?

The heat of solution of calcium chloride CaCl₂ is -82.8 kJ/mol, and the combined heats of hydration of 1 mole of gaseous calcium ions and 2 mole of gaseous chloride ions is -2327 kJ.What is the lattice energy of calcium chloride?

Find $\Delta$ H°_rxn for the reaction 2Ag₂S(s)+ 2H₂O(l) $\rarr$ 4Ag(s)+ 2H₂S(g)+ O₂(g). [ $\Delta$ H°_f (Ag₂S(s))= -32.6 kJ/mol; $\Delta$ H°_f (H₂S(g))= -20.5 kJ/mol; $\Delta$ H°_f (H₂O(l))= -285.5 kJ/mol]

What is the standard enthalpy of formation of H₂(g)at 25°C?

When an automobile engine starts, the metal parts immediately begin to absorb heat released during the combustion of gasoline. How much heat will be absorbed by a 165 kg iron engine block as the temperature rises from 15.7°C to 95.7°C? (The specific heat of iron is 0.489 J/g·°C.)

The heat of combustion of propane, C₃H₈, 2220 kJ/mol.The specific heat of copper is 0.385 J/g.°C.How many grams of propane must be burned to raise the temperature of a 10.0 kg block of copper from 25.0°C to 65.0°C, assuming none of the heat is lost to the surroundings

The heat of neutralization of HCl by NaOH is $\Delta$ H°_rxn = -56.2 kJ/mol. How much heat is released when 125 mL of 1.750 M HCl is mixed with 195 mL of 0.667 M NaOH?

The specific heat of silver is 0.235 J/g·°C. How many joules of heat are required to heat a 75 g silver spoon from 20°C to 35°C?

Find $\Delta$ H°_rxn for the reaction 2Na(s)+ 2H₂O(l) $\rarr$ 2NaOH(aq)+ 2H₂(g). [ $\Delta$ H°_f (NaOH(aq))= -426.8 kJ/mol; $\Delta$ H°_f (H₂O(l))= -285.5 kJ/mol]

Find $\Delta$ H°_rxn for the reaction CH₄(g)+ 2O₂(g) $\rarr$ CO₂(g)+ 2H₂O(l). [ $\Delta$ H°_f (CH₄(g))= -74.8 kJ/mol; $\Delta$ H°_f (CO₂(g))= -393.5 kJ/mol; $\Delta$ H°_f (H₂O(l))= -285.5 kJ/mol]

The value of $\Delta$ H°_rxn for the following reaction is -6535 kJ/mol. 2C₆H₆(l)+ 15O₂(g) $\rarr$ 12CO₂(g)+ 6H₂O(g) How many kilojoules of heat will be evolved during the combustion of 16.0 g of C₆H₆(l)?

A 26.2 g piece of copper metal is heated from 21.5°C to 201.6°C. Calculate the amount of heat absorbed by the metal. The specific heat of Cu is 0.385 J/g·°C.

What would be the standard enthalpy change for the reaction of one mole of H₂(g)with one mole of Cl₂(g)to produce two moles of HCl(g)at standard state conditions? [ $\Delta$ H°_f (HCl(g))= -92.3 kJ/mol]

Quiz 6: Thermo-Chemistry

The heat of solution of NH4NO3 is 26.2 kJ/mol. Is heat evolved or absorbed when a solution of NH4NO3 is diluted by addition of more water?

The heat of solution of calcium chloride CaCl2 is -82.8 kJ/mol, and the combined heats of hydration of 1 mole of gaseous calcium ions and 2 mole of gaseous chloride ions is -2327 kJ.What is the lattice energy of calcium chloride?

Find Δ\DeltaΔ H°rxn for the reaction 2Ag2S(s)+ 2H2O(l) →\rarr→ 4Ag(s)+ 2H2S(g)+ O2(g). [ Δ\DeltaΔ H°f (Ag2S(s))= -32.6 kJ/mol; Δ\DeltaΔ H°f (H2S(g))= -20.5 kJ/mol; Δ\DeltaΔ H°f (H2O(l))= -285.5 kJ/mol]

What is the standard enthalpy of formation of H2(g)at 25°C?

When an automobile engine starts, the metal parts immediately begin to absorb heat released during the combustion of gasoline. How much heat will be absorbed by a 165 kg iron engine block as the temperature rises from 15.7°C to 95.7°C? (The specific heat of iron is 0.489 J/g·°C.)

The heat of combustion of propane, C3H8, 2220 kJ/mol.The specific heat of copper is 0.385 J/g.°C.How many grams of propane must be burned to raise the temperature of a 10.0 kg block of copper from 25.0°C to 65.0°C, assuming none of the heat is lost to the surroundings

The heat of neutralization of HCl by NaOH is Δ\DeltaΔ H°rxn = -56.2 kJ/mol. How much heat is released when 125 mL of 1.750 M HCl is mixed with 195 mL of 0.667 M NaOH?

The specific heat of silver is 0.235 J/g·°C. How many joules of heat are required to heat a 75 g silver spoon from 20°C to 35°C?

Find Δ\DeltaΔ H°rxn for the reaction 2Na(s)+ 2H2O(l) →\rarr→ 2NaOH(aq)+ 2H2(g). [ Δ\DeltaΔ H°f (NaOH(aq))= -426.8 kJ/mol; Δ\DeltaΔ H°f (H2O(l))= -285.5 kJ/mol]

Find Δ\DeltaΔ H°rxn for the reaction CH4(g)+ 2O2(g) →\rarr→ CO2(g)+ 2H2O(l). [ Δ\DeltaΔ H°f (CH4(g))= -74.8 kJ/mol; Δ\DeltaΔ H°f (CO2(g))= -393.5 kJ/mol; Δ\DeltaΔ H°f (H2O(l))= -285.5 kJ/mol]

The value of Δ\DeltaΔ H°rxn for the following reaction is -6535 kJ/mol. 2C6H6(l)+ 15O2(g) →\rarr→ 12CO2(g)+ 6H2O(g) How many kilojoules of heat will be evolved during the combustion of 16.0 g of C6H6(l)?

A 26.2 g piece of copper metal is heated from 21.5°C to 201.6°C. Calculate the amount of heat absorbed by the metal. The specific heat of Cu is 0.385 J/g·°C.

What would be the standard enthalpy change for the reaction of one mole of H2(g)with one mole of Cl2(g)to produce two moles of HCl(g)at standard state conditions? [ Δ\DeltaΔ H°f (HCl(g))= -92.3 kJ/mol]

The heat of solution of NH₄NO₃ is 26.2 kJ/mol. Is heat evolved or absorbed when a solution of NH₄NO₃ is diluted by addition of more water?

The heat of solution of calcium chloride CaCl₂ is -82.8 kJ/mol, and the combined heats of hydration of 1 mole of gaseous calcium ions and 2 mole of gaseous chloride ions is -2327 kJ.What is the lattice energy of calcium chloride?

Find $\Delta$ H°_rxn for the reaction 2Ag₂S(s)+ 2H₂O(l) $\rarr$ 4Ag(s)+ 2H₂S(g)+ O₂(g). [ $\Delta$ H°_f (Ag₂S(s))= -32.6 kJ/mol; $\Delta$ H°_f (H₂S(g))= -20.5 kJ/mol; $\Delta$ H°_f (H₂O(l))= -285.5 kJ/mol]

What is the standard enthalpy of formation of H₂(g)at 25°C?

The heat of combustion of propane, C₃H₈, 2220 kJ/mol.The specific heat of copper is 0.385 J/g.°C.How many grams of propane must be burned to raise the temperature of a 10.0 kg block of copper from 25.0°C to 65.0°C, assuming none of the heat is lost to the surroundings

The heat of neutralization of HCl by NaOH is $\Delta$ H°_rxn = -56.2 kJ/mol. How much heat is released when 125 mL of 1.750 M HCl is mixed with 195 mL of 0.667 M NaOH?

Find $\Delta$ H°_rxn for the reaction 2Na(s)+ 2H₂O(l) $\rarr$ 2NaOH(aq)+ 2H₂(g). [ $\Delta$ H°_f (NaOH(aq))= -426.8 kJ/mol; $\Delta$ H°_f (H₂O(l))= -285.5 kJ/mol]

Find $\Delta$ H°_rxn for the reaction CH₄(g)+ 2O₂(g) $\rarr$ CO₂(g)+ 2H₂O(l). [ $\Delta$ H°_f (CH₄(g))= -74.8 kJ/mol; $\Delta$ H°_f (CO₂(g))= -393.5 kJ/mol; $\Delta$ H°_f (H₂O(l))= -285.5 kJ/mol]

The value of $\Delta$ H°_rxn for the following reaction is -6535 kJ/mol. 2C₆H₆(l)+ 15O₂(g) $\rarr$ 12CO₂(g)+ 6H₂O(g) How many kilojoules of heat will be evolved during the combustion of 16.0 g of C₆H₆(l)?

What would be the standard enthalpy change for the reaction of one mole of H₂(g)with one mole of Cl₂(g)to produce two moles of HCl(g)at standard state conditions? [ $\Delta$ H°_f (HCl(g))= -92.3 kJ/mol]