Question 1

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.)

Accepted Answer

The answer of When an automobile engine starts, the metal...

Question 2

The work done on the surroundings by the expansion of a gas is w = -P$\Delta$V.

Accepted Answer

This is the correct formula for calculating the work done on the surroundings by the expansion of a gas.

Question 3

A feverish student weighing 75 kilograms was immersed in 400.kg of water at 4.0°C to try to reduce the fever.The student's body temperature dropped from 40.0°C to 37.0°C.Assuming the specific heat of the student to be 3.77 J/g·°C, what was the final temperature of the water?

Accepted Answer

The answer of A feverish student weighing 75 kilograms was...

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]

Accepted Answer

The answer of Find $\Delta$H°_rxn for the reaction 2Ag₂S(s)+ 2H₂O(l)$\rarr$4Ag(s)+ 2H₂S(g)+...

Question 5

What would be the standard enthalpy change for the reaction of 1.00 mole of H₂(g)with 1.00 mole of Cl₂(g)to produce 2.00 moles of HCl(g)at standard state conditions? $\Delta$H°_f (HCl(g))= -92.3 kJ/mol]

Accepted Answer

The answer of What would be the standard enthalpy change...

Question 6

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)?

Accepted Answer

The answer of The value of $\Delta$H°_rxn for the following...

Question 7

If 2Mg(s)+ O₂(g)$\rarr$2MgO(s), $\Delta$H° = -1203.6 kJ/mol. For Mg(s)+ (1/2)O₂(g)$\rarr$MgO(s), the enthalpy change is $\Delta$H = -601.8 kJ/mol.

Accepted Answer

The given reaction is half of the original reaction, so the enthalpy change is also halved.

Question 8

Calculate the heat released (kJ)in the reaction of 3.50 g of acetylene (C₂H₂)and excess hydrogen gas to form ethane gas: C₂H₂(g)+ 2H₂(g)$\rarr$C₂H₆(g) Given: 2C₂H₂(g)+ 5O₂(g)$\rarr$4CO₂(g)+ 2H₂O(g),$\Delta$H = -2320 kJ/mol 2C₂H₆(g)+ 7O₂(g)$\rarr$4CO₂(g)+ 6H₂O(g),$\Delta$H = -3040 kJ/mol 2H₂(g)+ O₂(g)$\rarr$2H₂O(g),$\Delta$H = -572 kJ/mol

Accepted Answer

The answer of Calculate the heat released (kJ)in the reaction...

Question 9

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]

Accepted Answer

The answer of Find $\Delta$H°_rxn for the reaction 2Na(s)+ 2H₂O(l) $\rarr$...

Question 10

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]

Accepted Answer

The answer of Find $\Delta$H°_rxn for the reaction CH₄(g)+ 2O₂(g)$\rarr$CO₂(g)+ 2H₂O(l). [$\Delta$H°_f...

Question 11

Calculate the heat released (kJ)in the reaction of 2.20 g of sulfur dioxide gas and excess oxygen gas to form sulfur trioxide gas: 2SO₂(g)+ O₂(g)$\rarr$2SO₃(g) Given: S(s)+ O₂(g)$\rarr$ SO₂(g),$\Delta$H = -299 kJ/mol S(s)+ 3/2O₂(g)$\rarr$ SO₃(g),$\Delta$H = -395 kJ/mol

Accepted Answer

The answer of Calculate the heat released (kJ)in the reaction...

Question 12

The specific heats of water and iron are 4.184 and 0.444 J/g°C, respectively.When equal masses of water and iron both absorb the same amount of heat, the temperature increase of the water will be 5.42 times greater than that of the iron.

Accepted Answer

Let's assume that the equal masses of water and iron are m, and the amount of heat absorbed by both is Q.

Therefore, according to the formula for the heat absorbed by a specific substance:

Q = m × c × ΔT

where Q is the amount of heat absorbed, m is the mass of the substance, c is its specific heat capacity, and ΔT is the temperature change.

Since both water and iron absorb the same amount of heat (Q), we can set up an equation:

m × 4.184 × ΔT_w = m × 0.444 × ΔT_i

where ΔT_w and ΔT_i are the temperature changes of water and iron, respectively.

Dividing both sides by m and simplifying:

ΔT_w = 0.106 × ΔT_i

This means that the temperature increase of water will be 0.106 times that of iron.

However, the question says that the temperature increase of water is 5.42 times greater than that of iron.

Therefore, the statement is false, and the answer is B.

Question 13

The heat capacity of 20.0 g of water is 83.7 J/°C.

Accepted Answer

This is the correct heat capacity of 20.0 g of water at 25°C.

Question 14

Chemical reactions in a bomb calorimeter occur at constant pressure.

Accepted Answer

The answer of Chemical reactions in a bomb calorimeter occur...

Question 15

The combustion of one mole of benzene, C₆H₆, in oxygen liberates 3268 kJ of heat.The products of the reaction are carbon dioxide and water.How much heat is given off when 183 g of oxygen are reacted with excess benzene?

Accepted Answer

The answer of The combustion of one mole of benzene,...

Question 16

The heat absorbed by a system at constant pressure is equal to $\Delta$E + P$\Delta$V.

Accepted Answer

This is the statement of the first law of thermodynamics for a system at constant pressure. The heat absorbed (Q) is equal to the change in internal energy (ΔU) plus the work done (PΔV) on the surroundings. The formula given in the question is just a different way of writing this equation, where F1F1F1S1 represents the final state of the system and F1F1F1S0 represents the initial state.

Question 17

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?

Accepted Answer

The answer of At body temperature 2,404 joules of energy...

Question 18

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?

Accepted Answer

The answer of The specific heat of silver is 0.235...

Quiz 6: Thermochemistry

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 work done on the surroundings by the expansion of a gas is w = -P $\Delta$ V.

A feverish student weighing 75 kilograms was immersed in 400.kg of water at 4.0°C to try to reduce the fever.The student's body temperature dropped from 40.0°C to 37.0°C.Assuming the specific heat of the student to be 3.77 J/g·°C, what was the final temperature of the water?

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 would be the standard enthalpy change for the reaction of 1.00 mole of H₂(g)with 1.00 mole of Cl₂(g)to produce 2.00 moles of HCl(g)at standard state conditions? $\Delta$ H°_f (HCl(g))= -92.3 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)?

If 2Mg(s)+ O₂(g) $\rarr$ 2MgO(s), $\Delta$ H° = -1203.6 kJ/mol. For Mg(s)+ (1/2)O₂(g) $\rarr$ MgO(s), the enthalpy change is $\Delta$ H = -601.8 kJ/mol.

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]

Calculate the heat released (kJ)in the reaction of 2.20 g of sulfur dioxide gas and excess oxygen gas to form sulfur trioxide gas: 2SO₂(g)+ O₂(g) $\rarr$ 2SO₃(g) Given: S(s)+ O₂(g) $\rarr$ SO₂(g), $\Delta$ H = -299 kJ/mol S(s)+ 3/2O₂(g) $\rarr$ SO₃(g), $\Delta$ H = -395 kJ/mol

The specific heats of water and iron are 4.184 and 0.444 J/g°C, respectively.When equal masses of water and iron both absorb the same amount of heat, the temperature increase of the water will be 5.42 times greater than that of the iron.

The heat capacity of 20.0 g of water is 83.7 J/°C.

Chemical reactions in a bomb calorimeter occur at constant pressure.

The combustion of one mole of benzene, C₆H₆, in oxygen liberates 3268 kJ of heat.The products of the reaction are carbon dioxide and water.How much heat is given off when 183 g of oxygen are reacted with excess benzene?

The heat absorbed by a system at constant pressure is equal to $\Delta$ E + P $\Delta$ V.

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?

Quiz 6: Thermochemistry

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 work done on the surroundings by the expansion of a gas is w = -P Δ\DeltaΔ V.

A feverish student weighing 75 kilograms was immersed in 400.kg of water at 4.0°C to try to reduce the fever.The student's body temperature dropped from 40.0°C to 37.0°C.Assuming the specific heat of the student to be 3.77 J/g·°C, what was the final temperature of the water?

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 would be the standard enthalpy change for the reaction of 1.00 mole of H2(g)with 1.00 mole of Cl2(g)to produce 2.00 moles of HCl(g)at standard state conditions? Δ\DeltaΔ H°f (HCl(g))= -92.3 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)?

If 2Mg(s)+ O2(g) →\rarr→ 2MgO(s), Δ\DeltaΔ H° = -1203.6 kJ/mol. For Mg(s)+ (1/2)O2(g) →\rarr→ MgO(s), the enthalpy change is Δ\DeltaΔ H = -601.8 kJ/mol.

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]

Calculate the heat released (kJ)in the reaction of 2.20 g of sulfur dioxide gas and excess oxygen gas to form sulfur trioxide gas: 2SO2(g)+ O2(g) →\rarr→ 2SO3(g) Given: S(s)+ O2(g) →\rarr→ SO2(g), Δ\DeltaΔ H = -299 kJ/mol S(s)+ 3/2O2(g) →\rarr→ SO3(g), Δ\DeltaΔ H = -395 kJ/mol

The specific heats of water and iron are 4.184 and 0.444 J/g°C, respectively.When equal masses of water and iron both absorb the same amount of heat, the temperature increase of the water will be 5.42 times greater than that of the iron.

The heat capacity of 20.0 g of water is 83.7 J/°C.

Chemical reactions in a bomb calorimeter occur at constant pressure.

The combustion of one mole of benzene, C6H6, in oxygen liberates 3268 kJ of heat.The products of the reaction are carbon dioxide and water.How much heat is given off when 183 g of oxygen are reacted with excess benzene?

The heat absorbed by a system at constant pressure is equal to Δ\DeltaΔ E + P Δ\DeltaΔ V.

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?

The work done on the surroundings by the expansion of a gas is w = -P $\Delta$ V.

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 would be the standard enthalpy change for the reaction of 1.00 mole of H₂(g)with 1.00 mole of Cl₂(g)to produce 2.00 moles of HCl(g)at standard state conditions? $\Delta$ H°_f (HCl(g))= -92.3 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)?

If 2Mg(s)+ O₂(g) $\rarr$ 2MgO(s), $\Delta$ H° = -1203.6 kJ/mol. For Mg(s)+ (1/2)O₂(g) $\rarr$ MgO(s), the enthalpy change is $\Delta$ H = -601.8 kJ/mol.

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]

Calculate the heat released (kJ)in the reaction of 2.20 g of sulfur dioxide gas and excess oxygen gas to form sulfur trioxide gas: 2SO₂(g)+ O₂(g) $\rarr$ 2SO₃(g) Given: S(s)+ O₂(g) $\rarr$ SO₂(g), $\Delta$ H = -299 kJ/mol S(s)+ 3/2O₂(g) $\rarr$ SO₃(g), $\Delta$ H = -395 kJ/mol

The combustion of one mole of benzene, C₆H₆, in oxygen liberates 3268 kJ of heat.The products of the reaction are carbon dioxide and water.How much heat is given off when 183 g of oxygen are reacted with excess benzene?

The heat absorbed by a system at constant pressure is equal to $\Delta$ E + P $\Delta$ V.