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

A) -1835 kJ mol-1 B) -1364 kJ mol-1 C) -1050 kJ mol-1 D) -1786 kJ mol-1 E) -2100 kJ mol-1 A) -1835 kJ mol-1 B) -1364 kJ mol-1 C) -1050 kJ mol-1 D) -1786 kJ mol-1 E) -2100 kJ mol-1

Use the information provided to determine ΔrH° for the following reaction: ΔfH°(kJ mol-1)CH4(g)+ 4 Cl2(g)→ CCl4(g)+ 4 HCl(g)ΔrH° = ? CH4(g) -75 CCl4(g) -96 HCl(g) -92

A) -389 kJ mol-1 B) -113 kJ mol-1 C) +113 kJ mol-1 D) -71 kJ mol-1 E) +79 kJ mol-1 A) -389 kJ mol-1 B) -113 kJ mol-1 C) +113 kJ mol-1 D) -71 kJ mol-1 E) +79 kJ mol-1

According to the following reaction, how much energy is evolved during the reaction of 2.50 L B2H6 and 5.65 L Cl2 (both gases are initially at STP)? The molar mass of B2H6 is 27.67 g mol-1. B2H6(g)+ 6Cl2(g)→ 2BCl3(g)+ 6HCl(g)ΔrH° = -1396 kJ

A) 57.8 kJ B) 156 kJ C) 215 kJ D) 352 kJ E) 508 kJ A) 57.8 kJ B) 156 kJ C) 215 kJ D) 352 kJ E) 508 kJ

Using the following thermochemical equation, determine the amount of heat produced per kg of CO2 formed during the combustion of benzene (C6H6). 2C6H6(l)+ 15O2(g)→ 12CO2(g)+ 6H2O(g)ΔrH° = -6278 kJ

A) 1.43 × 105 kJ (kg CO2)-1 B) 2.30 × 104 kJ (kg CO2)-1 C) 4.34 × 104 kJ (kg CO2)-1 D) 1.19 × 104 kJ (kg CO2)-1 E) 8.40 × 105 kJ (kg CO2)-1 A) 1.43 × 105 kJ (kg CO2)-1 B) 2.30 × 104 kJ (kg CO2)-1 C) 4.34 × 104 kJ (kg CO2)-1 D) 1.19 × 104 kJ (kg CO2)-1 E) 8.40 × 105 kJ (kg CO2)-1

How much energy is required to decompose 765 g of PCl3 according to the reaction below? The molar mass of PCl3 is 137.32 g mol-1 and may be useful. 4PCl3(g)→ P4(s)+ 6Cl2(g)ΔrH° = +1207 kJ

A) 2.31 × 103 kJ B) 4.33 × 103 kJ C) 6.72 × 103 kJ D) 1.68 × 103 kJ E) 5.95 × 103 kJ A) 2.31 × 103 kJ B) 4.33 × 103 kJ C) 6.72 × 103 kJ D) 1.68 × 103 kJ E) 5.95 × 103 kJ

In the presence of excess oxygen, methane gas burns in a constant-pressure system to yield carbon dioxide and water: CH4 (g)+ 2O2 (g)→ + CO2(g)+ 2H2O (l)ΔrH = -890.0 kJ Calculate the value of q (kJ)in this exothermic reaction when 1.90 g of methane is combusted at constant pressure.

A) -105.7 kJ mol-1 B) 0.0342 kJ mol-1 C) -0.0095 kJ mol-1 D) 29.3 kJ mol-1 E) -1.06 × 105 kJ mol-1 A) -105.7 kJ mol-1 B) 0.0342 kJ mol-1 C) -0.0095 kJ mol-1 D) 29.3 kJ mol-1 E) -1.06 × 105 kJ mol-1

Exam 6: Thermochemistry

Calculate the amount (mass)of acetic acid (C₂H₄O₂, molar mass = 60.052 g mol^-1)that causes a bomb calorimeter with a heat capacity of 8.43 kJ °C^-1 to have a temperature increase from 24.5 °C to 36.8 °C. The $\Delta$ _rU for the combustion of acetic acid is -874.2 kJ mol^-1.

(Multiple Choice)

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Question 121

Two solutions, initially at 24.60 °C, are mixed in a coffee cup calorimeter (C_cal = 15.5 J °C^-1). When a 100.0 mL volume of 0.100 mol L^-1 AgNO₃ solution is mixed with a 100.0 mL sample of 0.200 mol L^-1 NaCl solution, the temperature in the calorimeter rises to 25.30 °C. Determine the $\Delta$ _rH° for the reaction as written below. Assume that the density and specific heat capacity of the solutions is the same as that of water. NaCl(aq)+ AgNO₃(aq)? AgCl(s)+ NaNO₃(aq) $\Delta$ _rH° = ?

(Multiple Choice)

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Question 122

For U to always be -, what must be true?

(Multiple Choice)

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Question 123

Using the following equation for the combustion of octane, calculate the amount of grams of carbon dioxide formed from 100.0 g of octane. The molar mass of octane is 114.33 g mol^-1. The molar mass of carbon dioxide is 44.0095 g mol^-1. 2C₈H₁₈ + 25O₂ → 16CO₂ + 18H₂O Δ_rH°= -11018 kJ

(Multiple Choice)

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Question 124

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

(Multiple Choice)

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Question 125

A 12.8 g sample of ethanol (C₂H₅OH)is burned in a bomb calorimeter with a heat capacity of 5.65 kJ °C^-1. Using the information below, determine the final temperature of the calorimeter if the initial temperature is 25.0°C. The molar mass of ethanol is 46.07 g mol^-1. C₂H₅OH(l)+ 3O₂(g)→ 2CO₂(g)+ 3H₂O(g)Δ_rU= -1235 kJ mol^-1

(Multiple Choice)

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Question 126

Calculate the amount of heat (in kJ)required to raise the temperature of a 79.0 g sample of ethanol from 298.0 K to 385.0 K. The specific heat capacity of ethanol is 2.42 J g^-1 °C^-1.

(Multiple Choice)

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Question 127

Where does the energy absorbed during an endothermic reaction go?

(Essay)

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Question 128

Use the information provided to determine Δ_rH° for the following reaction: Δ_fH°(kJ mol^-1)CH₄(g)+ 4 Cl₂(g)→ CCl₄(g)+ 4 HCl(g)Δ_rH°= ? CH₄(g) -75 CCl₄(g) -96 HCl(g) -92

(Multiple Choice)

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Question 129

Match the following. --q

(Multiple Choice)

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Question 130

The specific heat capacity of liquid water is 4.184 J g^-1 K^-1. How many joules of heat are needed to raise the temperature of 6.00 g of water from 36.0 °C to 75.0 °C?

(Multiple Choice)

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Question 131

A piece of iron (C = 0.449 J g^-1 °C^-1 and a piece of gold (C = 0.128 J g^-1 °C^-1)have identical masses. If the iron has an initial temperature of 498 K and the gold has an initial temperature of 298 K, which of the following statements is TRUE of the outcome when the two metals are placed in contact with one another? Assume no heat is lost to the surroundings.

(Multiple Choice)

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Question 132

According to the following reaction, how much energy is evolved during the reaction of 2.50 L B₂H₆ and 5.65 L Cl₂(both gases are initially at STP)? The molar mass of B₂H₆is 27.67 g mol^-1. B₂H₆(g)+ 6Cl₂(g)→ 2BCl₃(g)+ 6HCl(g)Δ_rH°= -1396 kJ

(Multiple Choice)

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Question 133

An unknown metal alloy, specific heat capacity = 0.372 J g^-1 °C^-1, has a temperature change of +21.7 °C after a heat transfer of 216.4 J. Calculate the mass of the alloy in question.

(Multiple Choice)

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Question 134

Explain the difference between ΔH and ΔU.

(Essay)

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Question 135

Identify a substance that is NOT in its standard state.

(Multiple Choice)

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Question 136

Using the following thermochemical equation, determine the amount of heat produced per kg of CO₂ formed during the combustion of benzene (C₆H₆). 2C₆H₆(l)+ 15O₂(g)→ 12CO₂(g)+ 6H₂O(g)Δ_rH°= -6278 kJ

(Multiple Choice)

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Question 137

How much energy is required to decompose 765 g of PCl₃ according to the reaction below? The molar mass of PCl₃ is 137.32 g mol^-1 and may be useful. 4PCl₃(g)→ P₄(s)+ 6Cl₂(g)Δ_rH° = +1207 kJ

(Multiple Choice)

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Question 138

Determine the final temperature of a gold nugget (mass = 376 g)that starts at 398 K and loses 4.85 kJ of heat to a snowbank when it is lost. The specific heat capacity of gold is 0.128 J g^-1 °C^-1.

(Multiple Choice)

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Question 139

In the presence of excess oxygen, methane gas burns in a constant-pressure system to yield carbon dioxide and water: CH₄ (g)+ 2O₂ (g)→ + CO₂(g)+ 2H₂O (l)Δ_rH = -890.0 kJ Calculate the value of q (kJ)in this exothermic reaction when 1.90 g of methane is combusted at constant pressure.

(Multiple Choice)

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Question 140

Showing 121 - 140 of 156

Exam 6: Thermochemistry

Calculate the amount (mass)of acetic acid (C2H4O2, molar mass = 60.052 g mol-1)that causes a bomb calorimeter with a heat capacity of 8.43 kJ °C-1 to have a temperature increase from 24.5 °C to 36.8 °C. The Δ\DeltaΔ rU for the combustion of acetic acid is -874.2 kJ mol-1.

For U to always be -, what must be true?

Using the following equation for the combustion of octane, calculate the amount of grams of carbon dioxide formed from 100.0 g of octane. The molar mass of octane is 114.33 g mol-1. The molar mass of carbon dioxide is 44.0095 g mol-1. 2C8H18 + 25O2 → 16CO2 + 18H2O ΔrH° = -11018 kJ

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

Calculate the amount of heat (in kJ)required to raise the temperature of a 79.0 g sample of ethanol from 298.0 K to 385.0 K. The specific heat capacity of ethanol is 2.42 J g-1 °C-1.

Where does the energy absorbed during an endothermic reaction go?

Use the information provided to determine ΔrH° for the following reaction: ΔfH°(kJ mol-1)CH4(g)+ 4 Cl2(g)→ CCl4(g)+ 4 HCl(g)ΔrH° = ? CH4(g) -75 CCl4(g) -96 HCl(g) -92

Match the following. --q

The specific heat capacity of liquid water is 4.184 J g-1 K-1. How many joules of heat are needed to raise the temperature of 6.00 g of water from 36.0 °C to 75.0 °C?

According to the following reaction, how much energy is evolved during the reaction of 2.50 L B2H6 and 5.65 L Cl2 (both gases are initially at STP)? The molar mass of B2H6 is 27.67 g mol-1. B2H6(g)+ 6Cl2(g)→ 2BCl3(g)+ 6HCl(g)ΔrH° = -1396 kJ

An unknown metal alloy, specific heat capacity = 0.372 J g-1 °C-1, has a temperature change of +21.7 °C after a heat transfer of 216.4 J. Calculate the mass of the alloy in question.

Explain the difference between ΔH and ΔU.

Identify a substance that is NOT in its standard state.

Using the following thermochemical equation, determine the amount of heat produced per kg of CO2 formed during the combustion of benzene (C6H6). 2C6H6(l)+ 15O2(g)→ 12CO2(g)+ 6H2O(g)ΔrH° = -6278 kJ

How much energy is required to decompose 765 g of PCl3 according to the reaction below? The molar mass of PCl3 is 137.32 g mol-1 and may be useful. 4PCl3(g)→ P4(s)+ 6Cl2(g)ΔrH° = +1207 kJ

Determine the final temperature of a gold nugget (mass = 376 g)that starts at 398 K and loses 4.85 kJ of heat to a snowbank when it is lost. The specific heat capacity of gold is 0.128 J g-1 °C-1.

In the presence of excess oxygen, methane gas burns in a constant-pressure system to yield carbon dioxide and water: CH4 (g)+ 2O2 (g)→ + CO2(g)+ 2H2O (l)ΔrH = -890.0 kJ Calculate the value of q (kJ)in this exothermic reaction when 1.90 g of methane is combusted at constant pressure.

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Calculate the amount (mass)of acetic acid (C₂H₄O₂, molar mass = 60.052 g mol^-1)that causes a bomb calorimeter with a heat capacity of 8.43 kJ °C^-1 to have a temperature increase from 24.5 °C to 36.8 °C. The $\Delta$ _rU for the combustion of acetic acid is -874.2 kJ mol^-1.

Using the following equation for the combustion of octane, calculate the amount of grams of carbon dioxide formed from 100.0 g of octane. The molar mass of octane is 114.33 g mol^-1. The molar mass of carbon dioxide is 44.0095 g mol^-1. 2C₈H₁₈ + 25O₂ → 16CO₂ + 18H₂O Δ_rH°= -11018 kJ

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

Calculate the amount of heat (in kJ)required to raise the temperature of a 79.0 g sample of ethanol from 298.0 K to 385.0 K. The specific heat capacity of ethanol is 2.42 J g^-1 °C^-1.

Use the information provided to determine Δ_rH° for the following reaction: Δ_fH°(kJ mol^-1)CH₄(g)+ 4 Cl₂(g)→ CCl₄(g)+ 4 HCl(g)Δ_rH°= ? CH₄(g) -75 CCl₄(g) -96 HCl(g) -92

The specific heat capacity of liquid water is 4.184 J g^-1 K^-1. How many joules of heat are needed to raise the temperature of 6.00 g of water from 36.0 °C to 75.0 °C?

According to the following reaction, how much energy is evolved during the reaction of 2.50 L B₂H₆ and 5.65 L Cl₂(both gases are initially at STP)? The molar mass of B₂H₆is 27.67 g mol^-1. B₂H₆(g)+ 6Cl₂(g)→ 2BCl₃(g)+ 6HCl(g)Δ_rH°= -1396 kJ

An unknown metal alloy, specific heat capacity = 0.372 J g^-1 °C^-1, has a temperature change of +21.7 °C after a heat transfer of 216.4 J. Calculate the mass of the alloy in question.

Using the following thermochemical equation, determine the amount of heat produced per kg of CO₂ formed during the combustion of benzene (C₆H₆). 2C₆H₆(l)+ 15O₂(g)→ 12CO₂(g)+ 6H₂O(g)Δ_rH°= -6278 kJ

How much energy is required to decompose 765 g of PCl₃ according to the reaction below? The molar mass of PCl₃ is 137.32 g mol^-1 and may be useful. 4PCl₃(g)→ P₄(s)+ 6Cl₂(g)Δ_rH° = +1207 kJ

Determine the final temperature of a gold nugget (mass = 376 g)that starts at 398 K and loses 4.85 kJ of heat to a snowbank when it is lost. The specific heat capacity of gold is 0.128 J g^-1 °C^-1.

In the presence of excess oxygen, methane gas burns in a constant-pressure system to yield carbon dioxide and water: CH₄ (g)+ 2O₂ (g)→ + CO₂(g)+ 2H₂O (l)Δ_rH = -890.0 kJ Calculate the value of q (kJ)in this exothermic reaction when 1.90 g of methane is combusted at constant pressure.