Energy and Chemical Change Quiz

For a chemical reaction, where the internal energy is given the symbol E,

• Efinal signifies the internal energy of the reactants.

• Einitial signifies the internal energy of the products.

• dE = Eproducts - Ereactants

• dE is positive if energy is released to the surroundings.

• dE is positive if energy is released by the chemical reaction.

Which statement is true?

• A state function is one whose value for a system depends on the method of preparation of the reactants and products.

• A state function is one whose value for a system is determined by the difference in temperature of the system, and not on the pressure of the system.

• A state function is one whose value for the system is determined by only the pressure of the system, and not on the temperature of the system.

• A state function is one whose value for a system is determined by the temperature of the system, and not on the composition of the system.

• A state function is one whose value for a system is determined by the composition of the system, the volume, the temperature, and the pressure.

A freshly baked pie is placed near an open window to cool. Which of the following statements best describes this situation?

• The pie is the system and loses heat to the surroundings.

• The pie is the system and gains heat from the surroundings.

• The pie is the surroundings and gains heat from the system.

• The pie is the surroundings and loses heat to the system.

• The pie is the surroundings and neither gains nor loses heat.

A certain oil used in industrial transformers has a density of 1.086 g mL-1 and a specific heat of 1.826 J g-1 °C-1. Calculate the heat capacity of one gallon of this oil. (1 gallon = 3.785 liters)

• 0.4442 kJ °C-1

• 0.5239 kJ °C-1

• 2.251 kJ °C-1

• 6.364 kJ °C-1

• 7.506 kJ °C-1

A 350.0 gram sample of copper is initially at 25.0 °C, and it absorbs 12.50 kJ of heat from its surroundings. What is its final temperature? (specific heat = 0.387 J g-1 °C-1 for copper)

• 38.8 °C

• 67.2 °C

• 92.2 °C

• 117.3 °C

• 156.7 °C

A bomb calorimeter consists of metal parts with a heat capacity of 850.0 J °C-1 and 1.100 × 103 grams of oil with a specific heat of 2.184 J g-1 °C-1. What is the heat capacity, in joules per degree, of the entire calorimeter?

• 1354 J °C-1

• 1952 J °C-1

• 2956 J °C-1

• 3252 J °C-1

• 4259 J °C-1

A bomb calorimeter consists of metal parts with a heat capacity of 925.0 J °C-1 and 1.100 ( 103 grams of oil with a specific heat of 2.814 J g-1 °C-1. What is the heat capacity, in joules per degree, of the entire calorimeter?

• 1321 J °C-1

• 2028 J °C-1

• 3703 J °C-1

• 4020 J °C-1

• 5698 J °C-1

A bomb calorimeter consists of metal parts with a heat capacity of 950.0 J °C-1 and 8.50 ( 102 grams of oil with a specific heat of 2.418 J g-1 °C-1. Calculate the amount of heat energy required, in kJ, to raise the temperature of the calorimeter from 25.00 °C to 31.60 °C.

• 4.91 kJ

• 11.9 kJ

• 19.8 kJ

• 20.8 kJ

• 28.7 kJ

A 113.25 gram sample of gold is initially at 100.0 °C. It loses 20.00 J of heat to its surroundings. What is its final temperature? (specific heat of gold = 0.129 J g-1 °C-1)

• 98.6 °C

• -98.6 °C

• 94.6 °C

• -94.6 °C

• 96.6 °C

A sample of chromium weighing 254 g was initially at a temperature of 25.88 °C. It required 843 joules of heat energy to increase the temperature to 32.75 °C. What is the molar heat capacity of the chromium? ______ (25.1 J mol-1 °C-1)

• 21.6 J mol-1 °C-1

• 25.1 J mol-1 °C-1

• 33.2 J mol-1 °C-1

• 37.3 J mol-1 °C-1

• 17.4 J mol-1 °C-1