Question 1

Which of the following is NOT a standard state?

Accepted Answer

A)  for a solid, it is 25°F 
B)  for a gas, it is 25°C 
C)  for a gas, it is 760 torr 
D)  for a solution, it is 1 M 
E)  for a liquid, it is 760 torr 
A)  for a solid, it is 25°F 
B)  for a gas, it is 25°C 
C)  for a gas, it is 760 torr 
D)  for a solution, it is 1 M 
E)  for a liquid, it is 760 torr

Question 2

According to the following reaction,how much energy is evolved during the reaction of 32.5 g B2H6 and 72.5 g Cl2? The molar mass of B2H6 is 27.67 g/mol. B2H6(g)+ 6 Cl2(g)→ 2 BCl3(g)+ 6 HCl(g)ΔH°rxn = -1396 kJ

Accepted Answer

A)  1640 kJ 
B)  238 kJ 
C)  1430 kJ 
D)  3070 kJ 
E)  429 kJ 
A)  1640 kJ 
B)  238 kJ 
C)  1430 kJ 
D)  3070 kJ 
E)  429 kJ

Question 3

Two solutions,initially at 24.69°C,are mixed in a coffee cup calorimeter.When a 200.0 mL volume of 0.100 M AgNO3 solution is mixed with a 100.0 mL sample of 0.100 M NaCl solution,the temperature in the calorimeter rises to 25.16°C.Determine the DH°rxn,in units of kJ/mol AgCl.Assume that the density and heat capacity of the solutions is the same as that of water.Hint: Write a balanced reaction for the process.

Accepted Answer

A)  -32 kJ/mol AgCl 
B)  -78 kJ/mol AgCl 
C)  -59 kJ/mol AgCl 
D)  -25 kJ/mol AgCl 
E)  -62 kJ/mol AgCl 
A)  -32 kJ/mol AgCl 
B)  -78 kJ/mol AgCl 
C)  -59 kJ/mol AgCl 
D)  -25 kJ/mol AgCl 
E)  -62 kJ/mol AgCl

Question 4

Identify a greenhouse gas.

Accepted Answer

A)  CO2 
B)  O2 
C)  Ne 
D)  NO 
E)  Cl2 
A)  CO2 
B)  O2 
C)  Ne 
D)  NO 
E)  Cl2

Question 5

Which of the following substances (with specific heat capacity provided)would show the greatest temperature change upon absorbing 100.0 J of heat?

Accepted Answer

A)  10.0 g Ag, CAg = 0.235 J/g°C 
B)  10.0 g Pb,   = 0.160 J/g°C 
C)  10.0 g water, Cwater = 4.18 J/g°C 
D)  10.0 g Fe, CFe = 0.449 J/g°C 
E)  10.0 g Ca, CCa= 0.650 J/g°C 
A)  10.0 g Ag, CAg = 0.235 J/g°C 
B)  10.0 g Pb,   = 0.160 J/g°C 
C)  10.0 g water, Cwater = 4.18 J/g°C 
D)  10.0 g Fe, CFe = 0.449 J/g°C 
E)  10.0 g Ca, CCa= 0.650 J/g°C

Question 6

Give the units of specific heat capacity.

Accepted Answer

A)  Jg/°F 
B) ( J/g °
C)  
C)  J/mole °C 
D)  g/°C 
E)  gmole °F 
A)  Jg/°F 
B) ( J/g °
C)  
C)  J/mole °C 
D)  g/°C 
E)  gmole °F

Question 7

In the presence of excess oxygen,methane gas burns in a constant-pressure system to yield carbon dioxide and water: CH4(g)+ 2 O2(g)→ CO2(g)+ 2 H2O(l)ΔH = -890.0 kJ
Calculate the value of q (kJ)in this exothermic reaction when 1.10 g of methane is combusted at constant pressure.

Accepted Answer

A)  -61.2 kJ 
B)  0.0198 kJ 
C)  -0.0163 kJ 
D)  50.6 kJ 
E)  -6.12 × 104 kJ 
A)  -61.2 kJ 
B)  0.0198 kJ 
C)  -0.0163 kJ 
D)  50.6 kJ 
E)  -6.12 × 104 kJ

Question 8

A 50.0-g sample of liquid water at 25.0°C is mixed with 23.0 g of water at 61.0°C.The final temperature of the water is ________°C.

Accepted Answer

A)  106 
B)  27.4 
C)  43.0 
D)  178 
E)  36.3 
A)  106 
B)  27.4 
C)  43.0 
D)  178 
E)  36.3

Question 9

Calculate the kinetic energy of a 150 g baseball moving at a speed of 37.m/s (83 mph).

Accepted Answer

A)  5.4 J 
B)  1.0 × 102 J 
C)  5.7 × 103 J 
D)  1.0 × 105 J 
E)  2.1 × 102 J 
A)  5.4 J 
B)  1.0 × 102 J 
C)  5.7 × 103 J 
D)  1.0 × 105 J 
E)  2.1 × 102 J

Question 10

A 4.50-g sample of copper metal at 25.0°C is heated by the addition of 145 J of energy.The final temperature of the copper is ________°C.The specific heat capacity of copper is

Accepted Answer

A)  37.2 
B)  25.0 
C)  59.8 
D)  110 
E)  84.8 
A)  37.2 
B)  25.0 
C)  59.8 
D)  110 
E)  84.8

Question 11

Why are the standard heats of formation for elements in their most stable form assigned a value of "0"?

Accepted Answer

We can't measure absolute enthalpy,but w

Question 12

Use the information provided to determine ΔH°rxn for the following reaction: ΔH°f (kJ/mol)CH4(g)+ 4 Cl2(g)→ CCl4(g)+ 4 HCl(g)ΔH°rxn = ?
CH4(g)-75
CCl4(g)-96
HCl(g)-92

Accepted Answer

A)  -389 kJ 
B)  -113 kJ 
C)  +113 kJ 
D)  -71 kJ 
E)  +79 kJ 
A)  -389 kJ 
B)  -113 kJ 
C)  +113 kJ 
D)  -71 kJ 
E)  +79 kJ

Question 13

The combustion of titanium with oxygen produces titanium dioxide: Ti(s)+   (g)→   (s)
When 1.720 g of titanium is combusted in a bomb calorimeter,the temperature of the calorimeter increases from 25.00°C to 80.10°C.In a separate experiment,the heat capacity of the calorimeter is measured to be 9.84 kJ/K.The heat of reaction for the combustion of a mole of Ti in this calorimeter is ________ kJ/mol.

Accepted Answer

A)  9.76 
B)  14.2 
C)  -311 
D)  -0.154 
E)  -1.51 ×   
A)  9.76 
B)  14.2 
C)  -311 
D)  -0.154 
E)  -1.51 ×

Question 14

Use the information provided to determine ΔH°rxn for the following reaction: ΔH°f (kJ/mol)3 Fe2O3(s)+ CO(g)→ 2 Fe3O4(s)+ CO2(g)ΔH°rxn = ?
Fe2O3(s)-824
Fe3O4(s)-1118
CO(g)-111
CO2(g)-394

Accepted Answer

A)  +277 kJ 
B)  -577 kJ 
C)  -47 kJ 
D)  +144 kJ 
E)  -111 kJ 
A)  +277 kJ 
B)  -577 kJ 
C)  -47 kJ 
D)  +144 kJ 
E)  -111 kJ

Question 15

Sodium metal reacts with water to produce hydrogen gas and sodium hydroxide according to the chemical equation shown below.When 0.030 mol of Na is added to 100.00 g of water,the temperature of the resulting solution rises from 25.00°C to 37.90°C.If the specific heat of the solution is 4.18 J/(g ∙ °C),calculate ΔH for the reaction,as written. 2 Na(s)+ 2 H2O(l)→ 2 NaOH(aq)+ H2(g)ΔH = ?

Accepted Answer

A)  -5.41 kJ 
B)  -90.0 kJ 
C)  -180 kJ 
D)  -360 kJ 
A)  -5.41 kJ 
B)  -90.0 kJ 
C)  -180 kJ 
D)  -360 kJ

Question 16

Use the standard reaction enthalpies given below to determine ΔH°rxn for the following reaction: P4(g)+ 10 Cl2(g)→ 4 PCl5(s)ΔH°rxn = ?
Given:
PCl5(s)→ PCl3(g)+ Cl2(g)ΔH°rxn = +157 kJ
P4(g)+ 6 Cl2(g)→ 4 PCl3(g)ΔH°rxn = -1207 kJ

Accepted Answer

A)  -1835 kJ 
B)  -1364 kJ 
C)  -1050. kJ 
D)  -1786 kJ 
E)  -2100. kJ 
A)  -1835 kJ 
B)  -1364 kJ 
C)  -1050. kJ 
D)  -1786 kJ 
E)  -2100. kJ

Question 17

Use the ?H°S1U1B1fS1U1B0 information provided to calculate ?H°S1U1B1rxnS1U1B0 for the following: ?H°S1U1B1fS1U1B0 (kJ/mol) SOS1U1B12S1U1B0ClS1U1B12S1U1B0(g)+ 2 HS1U1B12S1U1B0O(l)? 2 HCl(g)+ HS1U1B12S1U1B0SO4(l)

?H°S1U1B1rxnS1U1B0 = ?

SOS1U1B12S1U1B0ClS1U1B12S1U1B0(g)-364
HS1U1B12S1U1B0O(l)-286
HCl(g)-92
HS1U1B12S1U1B0SOS1U1B14S1U1B0(l)-814

Accepted Answer

A)  -256 kJ 
B)  +161 kJ 
C)  -62 kJ 
D)  +800. kJ 
E)  -422 kJ 
A)  -256 kJ 
B)  +161 kJ 
C)  -62 kJ 
D)  +800. kJ 
E)  -422 kJ

Question 18

Given w = 0,an endothermic reaction has the following.

Accepted Answer

A)  +ΔH and -ΔE 
B)  -ΔH and +ΔE 
C)  +ΔH and +ΔE 
D)  -ΔH and -ΔE 
A)  +ΔH and -ΔE 
B)  -ΔH and +ΔE 
C)  +ΔH and +ΔE 
D)  -ΔH and -ΔE

Question 19

Calculate the amount of heat (in kJ)required to raise the temperature of a 88.0 g sample of ethanol from 298.0 K to 405.0 K.The specific heat capacity of ethanol is 2.42 J/g°C.

Accepted Answer

A)  57.0 kJ 
B)  22.8 kJ 
C)  73.6 kJ 
D)  30.4 kJ 
E)  11.9 kJ 
A)  57.0 kJ 
B)  22.8 kJ 
C)  73.6 kJ 
D)  30.4 kJ 
E)  11.9 kJ

Question 20

What volume of benzene (C6H6,d= 0.88 g/mL,molar mass = 78.11 g/mol)is required to produce   of heat according to the following reaction? 2 C6H6(l)+ 15 O2(g)→ 12 CO2(g)+ 6 H2O(g)ΔH°rxn = -6278 kJ

Accepted Answer

A)  75 mL 
B)  37 mL 
C)  21 mL 
D)  19 mL 
E)  42 mL 
A)  75 mL 
B)  37 mL 
C)  21 mL 
D)  19 mL 
E)  42 mL

Exam 6: Thermochemistry

Which of the following is NOT a standard state?

According to the following reaction,how much energy is evolved during the reaction of 32.5 g B2H6 and 72.5 g Cl2? The molar mass of B2H6 is 27.67 g/mol. B2H6(g)+ 6 Cl2(g)→ 2 BCl3(g)+ 6 HCl(g)ΔH°rxn = -1396 kJ

Identify a greenhouse gas.

Which of the following substances (with specific heat capacity provided)would show the greatest temperature change upon absorbing 100.0 J of heat?

Give the units of specific heat capacity.

In the presence of excess oxygen,methane gas burns in a constant-pressure system to yield carbon dioxide and water: CH4(g)+ 2 O2(g)→ CO2(g)+ 2 H2O(l)ΔH = -890.0 kJ Calculate the value of q (kJ)in this exothermic reaction when 1.10 g of methane is combusted at constant pressure.

A 50.0-g sample of liquid water at 25.0°C is mixed with 23.0 g of water at 61.0°C.The final temperature of the water is ________°C.

Calculate the kinetic energy of a 150 g baseball moving at a speed of 37.m/s (83 mph).

A 4.50-g sample of copper metal at 25.0°C is heated by the addition of 145 J of energy.The final temperature of the copper is ________°C.The specific heat capacity of copper is

Why are the standard heats of formation for elements in their most stable form assigned a value of "0"?

Use the information provided to determine ΔH°rxn for the following reaction: ΔH°f (kJ/mol)CH4(g)+ 4 Cl2(g)→ CCl4(g)+ 4 HCl(g)ΔH°rxn = ? CH4(g)-75 CCl4(g)-96 HCl(g)-92

Use the information provided to determine ΔH°rxn for the following reaction: ΔH°f (kJ/mol)3 Fe2O3(s)+ CO(g)→ 2 Fe3O4(s)+ CO2(g)ΔH°rxn = ? Fe2O3(s)-824 Fe3O4(s)-1118 CO(g)-111 CO2(g)-394

Use the standard reaction enthalpies given below to determine ΔH°rxn for the following reaction: P4(g)+ 10 Cl2(g)→ 4 PCl5(s)ΔH°rxn = ? Given: PCl5(s)→ PCl3(g)+ Cl2(g)ΔH°rxn = +157 kJ P4(g)+ 6 Cl2(g)→ 4 PCl3(g)ΔH°rxn = -1207 kJ

Use the ?H°f information provided to calculate ?H°rxn for the following: ?H°f (kJ/mol) SO2Cl2(g)+ 2 H2O(l)? 2 HCl(g)+ H2SO4(l) ?H°rxn = ? SO2Cl2(g)-364 H2O(l)-286 HCl(g)-92 H2SO4(l)-814

Given w = 0,an endothermic reaction has the following.

Calculate the amount of heat (in kJ)required to raise the temperature of a 88.0 g sample of ethanol from 298.0 K to 405.0 K.The specific heat capacity of ethanol is 2.42 J/g°C.

What volume of benzene (C6H6,d= 0.88 g/mL,molar mass = 78.11 g/mol)is required to produce of heat according to the following reaction? 2 C6H6(l)+ 15 O2(g)→ 12 CO2(g)+ 6 H2O(g)ΔH°rxn = -6278 kJ

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According to the following reaction,how much energy is evolved during the reaction of 32.5 g B₂H₆ and 72.5 g Cl₂? The molar mass of B₂H₆is 27.67 g/mol. B₂H₆(g)+ 6 Cl₂(g)→ 2 BCl₃(g)+ 6 HCl(g)ΔH°_rxn= -1396 kJ

In the presence of excess oxygen,methane gas burns in a constant-pressure system to yield carbon dioxide and water: CH₄(g)+ 2 O₂(g)→ CO₂(g)+ 2 H₂O(l)ΔH = -890.0 kJ Calculate the value of q (kJ)in this exothermic reaction when 1.10 g of methane is combusted at constant pressure.

Use the information provided to determine ΔH°_rxn for the following reaction: ΔH°_f (kJ/mol)CH₄(g)+ 4 Cl₂(g)→ CCl₄(g)+ 4 HCl(g)ΔH°_rxn= ? CH₄(g)-75 CCl₄(g)-96 HCl(g)-92

Use the information provided to determine ΔH°_rxn for the following reaction: ΔH°_f (kJ/mol)3 Fe₂O₃(s)+ CO(g)→ 2 Fe₃O₄(s)+ CO₂(g)ΔH°_rxn= ? Fe₂O₃(s)-824 Fe₃O₄(s)-1118 CO(g)-111 CO₂(g)-394

Use the standard reaction enthalpies given below to determine ΔH°_rxn for the following reaction: P₄(g)+ 10 Cl₂(g)→ 4 PCl₅(s)ΔH°_rxn= ? Given: PCl₅(s)→ PCl₃(g)+ Cl₂(g)ΔH°_rxn= +157 kJ P₄(g)+ 6 Cl₂(g)→ 4 PCl₃(g)ΔH°_rxn = -1207 kJ

Use the ?H°_f information provided to calculate ?H°_rxn for the following: ?H°_f (kJ/mol) SO₂Cl₂(g)+ 2 H₂O(l)? 2 HCl(g)+ H₂SO4(l) ?H°_rxn = ? SO₂Cl₂(g)-364 H₂O(l)-286 HCl(g)-92 H₂SO₄(l)-814

What volume of benzene (C₆H₆,d= 0.88 g/mL,molar mass = 78.11 g/mol)is required to produce of heat according to the following reaction? 2 C₆H₆(l)+ 15 O₂(g)→ 12 CO₂(g)+ 6 H₂O(g)ΔH°_rxn= -6278 kJ