Calculate the internal energy change, ΔrU, for the combustion of 29.3 g of vitamin C (C6H8O6, molar mass = 176.124 g mol-1) if the combustion inside a bomb calorimeter, Ccal = 8.31 kJ °C-1, causes a temperature change from 21.5 °C to 68.3 °C.

A) -1.78 × 103 kJ mol-1 B) -2.34 × 103 kJ mol-1 C) -6.03 × 103 kJ mol-1 D) -9.19 × 102 kJ mol-1 E) -1.67 × 102 kJ mol-1 A) -1.78 × 103 kJ mol-1 B) -2.34 × 103 kJ mol-1 C) -6.03 × 103 kJ mol-1 D) -9.19 × 102 kJ mol-1 E) -1.67 × 102 kJ mol-1

How much heat is absorbed/released when 40.00 g of NH3(g) reacts in the presence of excess (g) to produce NO(g) and H2O(l) according to the following chemical equation? 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(l) H° = 1168 kJ

A) 685.8 kJ of heat are absorbed. B) 685.8 kJ of heat are released. C) 2743 kJ of heat are absorbed. D) 2743 kJ of heat are released. A) 685.8 kJ of heat are absorbed. B) 685.8 kJ of heat are released. C) 2743 kJ of heat are absorbed. D) 2743 kJ of heat are released.

Use the H° and H° information provided to calculate H° for SO3(g): H° (kJ ) 2SO2(g) + O2(g) → 2SO3(g) H° = -198 kJ SO2(g) -297

A) -792 kJ mol-1 B) -248 kJ mol-1 C) -495 kJ mol-1 D) -578 kJ mol-1 E) -396 kJ mol-1 A) -792 kJ mol-1 B) -248 kJ mol-1 C) -495 kJ mol-1 D) -578 kJ mol-1 E) -396 kJ mol-1

Use the standard reaction enthalpies given below to determine H° for the following reaction: 2NO(g) + O2(g) → 2NO2(g) H° = ? Given: N2(g) + O2(g) → 2NO(g) H° = +183 kJ 1/2 N2(g) + O2(g) → NO2(g) H° = +33 kJ

A) -150. kJ mol-1 B) -117 kJ mol-1 C) -333 kJ mol-1 D) +115 kJ mol-1 E) +238 kJ mol-1 A) -150. kJ mol-1 B) -117 kJ mol-1 C) -333 kJ mol-1 D) +115 kJ mol-1 E) +238 kJ mol-1

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

Exam 6: Thermochemistry

Two aqueous solutions are both at room temperature and are then mixed in a coffee cup calorimeter. The reaction causes the temperature of the resulting solution to fall below room temperature. Which of the following statements is TRUE?

(Multiple Choice)

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Question 61

Calculate the internal energy change, Δ_rU, for the combustion of 29.3 g of vitamin C (C₆H₈O₆, molar mass = 176.124 g mol^-1) if the combustion inside a bomb calorimeter, C_cal = 8.31 kJ °C^-1, causes a temperature change from 21.5 °C to 68.3 °C.

(Multiple Choice)

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Question 62

How much heat is absorbed/released when 40.00 g of NH₃(g) reacts in the presence of excess (g) to produce NO(g) and H₂O(l) according to the following chemical equation? 4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(l) H° = 1168 kJ

(Multiple Choice)

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Question 63

Using the following thermochemical equation, determine the amount of heat produced from the combustion of 24.3 g benzene (C₆H₆). The molar mass of benzene is 78.11 g . 2C₆H₆(l) + 15O₂(g) → 12CO₂(g) + 6H₂O(g) H°= -6278 kJ

(Multiple Choice)

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Question 64

Use the H° and H°information provided to calculate H° for SO₃(g): H°(kJ ) 2SO₂(g) + O₂(g) → 2SO₃(g) H°= -198 kJ SO₂(g) -297

(Multiple Choice)

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Question 65

Calculate the change in internal energy (ΔU) for a system that is giving off 45.0 kJ of heat and is performing 855 J of work on the surroundings.

(Multiple Choice)

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Question 66

Calculate the amount of heat (in kJ) necessary to raise the temperature of 47.8 g benzene by 57.0 K. The specific heat capacity of benzene is 1.05 J g^-1 °C^-1.

(Multiple Choice)

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Question 67

Which of the following signs on q and w represent a system that is doing work on the surroundings as well as gaining heat from the surroundings?

(Multiple Choice)

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Question 68

Calculate the amount (mass) of acetaldehyde (C₂H₄O, molar mass = 44.0526 g mol^-¹) that causes a bomb calorimeter with a heat capacity of 12.91 kJ °C^-1 to have a temperature increase from 27.8 °C to 41.7 °C. The Δ_rU for the combustion of acetaldehyde is -1166.9 kJ mol^-1.

(Multiple Choice)

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Question 69

9.26 g of an unknown solid is dissolved in a coffee cup calorimeter that contains 62.0 mL of water. The measured temperature increased from 23.4 °C to 24.7 °C. The specific heat of water is 4.184 J g^-1 °C^-1, and assume the density of the solution is 1.00 g mL^-1. Calculate the molecular weight of the unknown solid if the H was determined to be -2.51 kJ mol^-1 via another experiment.

(Multiple Choice)

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Question 70

The standard state of carbon is ________.

(Short Answer)

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Question 71

A piece of gold with a mass of 21.0 g was heated to 100.0 °C and placed inside a coffee cup calorimeter. The temperature of the water inside the calorimeter increased from 23.8 °C to 25.5 °C. The specific heat capacity of water is 4.184 J g^-1 °C^-1 and the specific heat capacity of gold is 0.129 J g^-1 °C^-1. Calculate the mass of water contained inside the calorimeter.

(Multiple Choice)

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Question 72

Calculate the mass of sodium cyanate (NaOCN, molar mass = 65.0066 g mol^-1) required to lower the temperature from 24.1 °C to 23.0 °C in a coffee cup calorimeter containing 98 mL of water. The enthalpy of solution for NaOCN is 19.20 kJ mol^-1. The specific heat of water is 4.184 J g^-1 °C^-1 and assume the density of the solution is 1.00 g mL^-1.

(Multiple Choice)

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Question 73

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

(Multiple Choice)

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Question 74

Identify the unit of heat capacity.

(Multiple Choice)

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Question 75

Match the following. -energy associated with the position of an object

(Multiple Choice)

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Question 76

Use the standard reaction enthalpies given below to determine H° for the following reaction: 2NO(g) + O₂(g) → 2NO₂(g) H°= ? Given: N₂(g) + O₂(g) → 2NO(g) H°= +183 kJ 1/2 N₂(g) + O₂(g) → NO₂(g) H°= +33 kJ

(Multiple Choice)

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Question 77

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

(Multiple Choice)

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Question 78

Define molar heat capacity.

(Multiple Choice)

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Question 79

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 80

Showing 61 - 80 of 161

Exam 6: Thermochemistry

Two aqueous solutions are both at room temperature and are then mixed in a coffee cup calorimeter. The reaction causes the temperature of the resulting solution to fall below room temperature. Which of the following statements is TRUE?

Calculate the internal energy change, ΔrU, for the combustion of 29.3 g of vitamin C (C6H8O6, molar mass = 176.124 g mol-1) if the combustion inside a bomb calorimeter, Ccal = 8.31 kJ °C-1, causes a temperature change from 21.5 °C to 68.3 °C.

How much heat is absorbed/released when 40.00 g of NH3(g) reacts in the presence of excess (g) to produce NO(g) and H2O(l) according to the following chemical equation? 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(l) H° = 1168 kJ

Using the following thermochemical equation, determine the amount of heat produced from the combustion of 24.3 g benzene (C6H6). The molar mass of benzene is 78.11 g . 2C6H6(l) + 15O2(g) → 12CO2(g) + 6H2O(g) H° = -6278 kJ

Use the H° and H° information provided to calculate H° for SO3(g): H° (kJ ) 2SO2(g) + O2(g) → 2SO3(g) H° = -198 kJ SO2(g) -297

Calculate the change in internal energy (ΔU) for a system that is giving off 45.0 kJ of heat and is performing 855 J of work on the surroundings.

Calculate the amount of heat (in kJ) necessary to raise the temperature of 47.8 g benzene by 57.0 K. The specific heat capacity of benzene is 1.05 J g-1 °C-1.

Which of the following signs on q and w represent a system that is doing work on the surroundings as well as gaining heat from the surroundings?

Calculate the amount (mass) of acetaldehyde (C2H4O, molar mass = 44.0526 g mol-1) that causes a bomb calorimeter with a heat capacity of 12.91 kJ °C-1 to have a temperature increase from 27.8 °C to 41.7 °C. The ΔrU for the combustion of acetaldehyde is -1166.9 kJ mol-1.

The standard state of carbon is ________.

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

Identify the unit of heat capacity.

Match the following. -energy associated with the position of an object

Use the standard reaction enthalpies given below to determine H° for the following reaction: 2NO(g) + O2(g) → 2NO2(g) H° = ? Given: N2(g) + O2(g) → 2NO(g) H° = +183 kJ 1/2 N2(g) + O2(g) → NO2(g) H° = +33 kJ

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

Define molar heat capacity.

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.

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Calculate the internal energy change, Δ_rU, for the combustion of 29.3 g of vitamin C (C₆H₈O₆, molar mass = 176.124 g mol^-1) if the combustion inside a bomb calorimeter, C_cal = 8.31 kJ °C^-1, causes a temperature change from 21.5 °C to 68.3 °C.

How much heat is absorbed/released when 40.00 g of NH₃(g) reacts in the presence of excess (g) to produce NO(g) and H₂O(l) according to the following chemical equation? 4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(l) H° = 1168 kJ

Using the following thermochemical equation, determine the amount of heat produced from the combustion of 24.3 g benzene (C₆H₆). The molar mass of benzene is 78.11 g . 2C₆H₆(l) + 15O₂(g) → 12CO₂(g) + 6H₂O(g) H°= -6278 kJ

Use the H° and H°information provided to calculate H° for SO₃(g): H°(kJ ) 2SO₂(g) + O₂(g) → 2SO₃(g) H°= -198 kJ SO₂(g) -297

Calculate the amount of heat (in kJ) necessary to raise the temperature of 47.8 g benzene by 57.0 K. The specific heat capacity of benzene is 1.05 J g^-1 °C^-1.

Calculate the amount (mass) of acetaldehyde (C₂H₄O, molar mass = 44.0526 g mol^-¹) that causes a bomb calorimeter with a heat capacity of 12.91 kJ °C^-1 to have a temperature increase from 27.8 °C to 41.7 °C. The Δ_rU for the combustion of acetaldehyde is -1166.9 kJ mol^-1.

Use the standard reaction enthalpies given below to determine H° for the following reaction: 2NO(g) + O₂(g) → 2NO₂(g) H°= ? Given: N₂(g) + O₂(g) → 2NO(g) H°= +183 kJ 1/2 N₂(g) + O₂(g) → NO₂(g) H°= +33 kJ

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