Chapter 6 Practice Test

Question 1

What is the SI unit for energy?

Answer 1

joule

Question 2

What is the kinetic energy of a basketball having a mass of 0.65 kg that is falling at 3.5 m / s?

Answer 2

4.0 J

Question 3

Which of the following objects has non-zero potential energy, but zero kinetic energy?

Answer 3

An encyclopedia on the top shelf of a bookcase

Question 4

What are the products of metabolizing food?

Answer 4

carbon dioxide and water

Question 5

How many Calories are in 3 servings of the food described in the following label?

Answer 5

424.5 Cal

Question 6

How is excess energy stored in the body?

Answer 6

as fat

Question 7

What is the First Law of Thermodynamics?

Answer 7

The total energy in the universe is constant.

Question 8

In the equation E = q + w, what does the q represent

Answer 8

heat

Question 9

Which of the following is not a state function?

Answer 9

work

Question 10

What is the work in joules when a gas expands from 3.10 L to 6.40 L against a constant external pressure of 2.00 atm?
Use 1 L-atm = 101.325 J.

Answer 10

−669 J

Question 11

When w is positive, which of the following is true?

Answer 11

Work was done by the surroundings on the system.

Question 12

When q is negative, which of the following is true?

Answer 12

Heat flowed from the system to the surroundings.

Question 13

What is the correct definition of heat?

Answer 13

Heat is the energy that flows because of difference in temperature between the system and its surroundings.

Question 14

How much heat (in kJ) is absorbed by a 500. g sample of water when it is heated from 44.0°C to 67.0°C?
The specific heat capacity of water is 4.184 J / g°C.

Answer 14

48.1 kJ

Question 15

The first law of thermodynamics is written as, ΔE = q + w. What would ΔE be equal to when imposing a constant volume restriction to a system?

Answer 15

ΔE = qV

Question 16

Which of the following describes an endothermic reaction?

Answer 16

A reaction that moves heat from the surroundings into the system

Question 17

Change in enthalpy is equal to heat measured under what condition?

Answer 17

constant pressure

Question 18

A friend wants you to calculate the molar heat capacity of a given metal. He gives you the initial and final temperatures of the water in the calorimeter, the initial temperature of the metal, and the mass of the metal. You know that the molar heat capacity of water is 75.4 J / mol. What other information do you need before you can calculate the molar heat capacity of the metal?

Answer 18

The amount of water

Question 19

A calorimeter contains 75.0 g of water at an initial temperature of 25.2 °C. 151.28 g of copper metal at a temperature of 95.5 °C was placed in the calorimeter. The equilibrium temperature was 36.2 °C. The molar heat capacity of water is 75.4 J / mol °C. Determine the molar heat capacity of the copper.

Answer 19

24.5 J / mol °C

Question 20

What does the C in the equation qsurr = CΔT represent?

Answer 20

The heat capacity of the calorimeter and its surroundings

Question 21

A reaction is carried out in a bomb calorimeter. Which of the following is TRUE if the heat of the reaction is found to be a negative value?

Answer 21

The heat of the surroundings increased

Question 22

The combustion of methane is given by the following equation:
CH4(g) + 2 O2(g) → CO2(g) + H2O(g) ΔH = −890 kJ
What is the enthalpy change for 5 moles of methane?

Answer 22

−4450 kJ

Question 23

When one mole of ice melts, the change in enthalpy is +6.0 kJ. What is the enthalpy change for the freezing of one mole of water?

Answer 23

−6.0 kJ

Question 24

Which of the following is not a standard enthalpy of formation reaction?

Answer 24

2H2(g) + O2(g) → 2H2O(l)

Question 25

Which of the following statements is not true about allotropes?

Answer 25

Allotropes have different forms at room temperature, but the same enthalpy.