Q: Which of the following is NOT a correct unit for energy?

$$\text{kg} \cdot \text{m} \cdot \text{s}^{-1}$$

Question 1

Which of the following best describes the First Law of Thermodynamics?

Accepted Answer

The total energy of the universe is constant; energy can be transferred or transformed but not created or destroyed.

Question 2

A curling stone slides across the ice and eventually comes to a stop. According to the law of conservation of energy, what happens to the stone's kinetic energy?

Accepted Answer

It is transformed into heat energy due to friction with the ice.

Question 3

Which of the following is the correct formula for calculating the work done by a force acting through a distance?

Accepted Answer

$$W = F 	imes d$$

Question 4

A chemical reaction in a hand warmer releases heat to your hands. Which of the following statements is true regarding the system and surroundings?

Accepted Answer

The system loses heat and $$q \u003c 0.$$

Question 5

Which of the following is NOT a correct unit for energy?

Accepted Answer

$$	ext{kg} \cdot 	ext{m} \cdot 	ext{s}^{-1}$$

Question 6

If 17.8 kcal of energy is required to heat a cup of coffee, what is this energy in joules? (Given: $$1 	ext{cal} = 4.184 	ext{J}$$, $$1 	ext{kcal} = 1000 	ext{cal})$$

Accepted Answer

$$74,500 	ext{J}$$

Question 7

Which of the following best describes a state function?

Accepted Answer

A property that depends only on the initial and final states, not the path taken.

Question 8

During the combustion of wood, which type of energy is primarily released?

Accepted Answer

Chemical potential energy is converted to heat and light.

Question 9

A reaction occurs in a sealed, rigid container and releases 500 J of heat to the surroundings. What is the sign and value of $$q$$ for the system?

Accepted Answer

$$q = -500 	ext{J}$$

Question 10

Which of the following scenarios best illustrates the conversion of potential energy to kinetic energy?

Accepted Answer

A ball held at a height and then dropped.

Question 11

Which equation correctly expresses the relationship between internal energy change ($$\Delta U$$), heat ($$q$$), and work ($$w$$)?

Accepted Answer

$$\Delta U = q + w$$

Question 12

A gas expands against a constant external pressure, doing 200 J of work on the surroundings and absorbing 150 J of heat. What is the change in internal energy ($$\Delta U) of $$the system?

Accepted Answer

$$\Delta U = -50 	ext{J}$$

Question 13

Which of the following best describes heat ($$q) in $$thermochemistry?

Accepted Answer

Energy transferred due to a difference in temperature.

Question 14

Which of the following is an example of work being done by a chemical system?

Accepted Answer

A reaction in a cylinder produces gas that pushes up a piston.

Question 15

Which of the following statements about energy diagrams is correct?

Accepted Answer

Reactants with higher internal energy than products release energy during the reaction.

Question 16

A 100 W light bulb is left on for 1 hour. How much energy does it consume in kilojoules? (Given: $$1 	ext{kWh} = 3.6 	imes 10^6$ 	ext{J})$$

Accepted Answer

$$360 	ext{kJ}$$

Question 17

Which of the following is NOT a form of kinetic energy?

Accepted Answer

Chemical potential energy

Question 18

In a chemical reaction, if the system absorbs heat from the surroundings, which of the following is true?

Accepted Answer

$$q \u003e 0$$ and the reaction is endothermic.

Question 19

Which of the following best describes the surroundings in a thermochemical experiment?

Accepted Answer

Everything in the universe except the system being studied.

Question 20

Which of the following is the correct conversion factor between calories and joules?

Accepted Answer

$$1 	ext{cal} = 4.184 	ext{J}$$

Chapter 6.1: Thermochemistry – The Nature of Energy and the First Law of Thermodynamics

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