Q: A person weighing 75.0 kg runs at a speed of 1.78 m/s. What is their kinetic energy?

$$E_k = \frac{1}{2} \times 75.0 \times (1.78)^2$ = 119 \text{ J}$$

Q: Which equation is used to estimate the enthalpy change of a reaction using bond energies?

$$\Delta H = \text{sum of bond enthalpies of bonds broken} - \text{sum of bond enthalpies of bonds formed}$$

Question 1

Which of the following best describes the first law of thermodynamics?

Accepted Answer

Energy cannot be created or destroyed, only converted from one form to another.

Question 2

A chemical reaction occurs in a sealed container at constant volume. Which equation correctly relates the change in internal energy to the heat exchanged?

Accepted Answer

$$\Delta U = q_v$$

Question 3

Which of the following is an example of an extensive state function?

Accepted Answer

Enthalpy

Question 4

A person weighing 75.0 kg runs at a speed of 1.78 m/s. What is their kinetic energy?

Accepted Answer

$$E_k = \frac{1}{2} 	imes 75.0 	imes (1.78)^2$ = 119 	ext{ J}$$

Question 5

Which process is exothermic?

Accepted Answer

Burning firewood

Question 6

What is the correct expression for enthalpy change at constant pressure?

Accepted Answer

$$\Delta H = \Delta U + P\Delta V$$

Question 7

Which of the following statements about entropy is TRUE?

Accepted Answer

Entropy is a measure of energy dispersal in a system.

Question 8

Which equation correctly relates Gibbs free energy to enthalpy and entropy?

Accepted Answer

$$G = H - TS$$

Question 9

If a reaction has $$\Delta H  0$$, what can be said about its spontaneity at all temperatures?

Accepted Answer

It is spontaneous at all temperatures.

Question 10

Which of the following best describes a system in thermodynamics?

Accepted Answer

The part of the universe we are interested in studying.

Question 11

Which calorimetry method is used to measure heat at constant volume?

Accepted Answer

Bomb calorimetry

Question 12

What is the SI unit for energy?

Accepted Answer

Joule

Question 13

Which of the following is a correct statement about phase transitions?

Accepted Answer

Energy must be added or removed for a phase transition to occur.

Question 14

Which of the following reactions would result in an increase in entropy?

Accepted Answer

$$N_2O_4(g) \rightarrow 2NO_2(g)$$

Question 15

Which equation is used to estimate the enthalpy change of a reaction using bond energies?

Accepted Answer

$$\Delta H = 	ext{sum of bond enthalpies of bonds broken} - 	ext{sum of bond enthalpies of bonds formed}$$

Question 16

Which of the following is TRUE about the equilibrium constant $$K$$ for a reaction?

Accepted Answer

It relates the concentrations or partial pressures of reactants and products at equilibrium.

Question 17

What is the correct relationship between the standard Gibbs free energy change and the equilibrium constant?

Accepted Answer

$$\Delta G^\circ = -RT \ln K$$

Question 18

Which of the following is a correct statement about ionic bonds?

Accepted Answer

Ionic bonds are formed by the electrostatic attraction between positive and negative ions.

Question 19

Which of the following is NOT a source of uncertainty in thermodynamic measurements?

Accepted Answer

Absolute certainty of measurement

Question 20

Which of the following statements about the third law of thermodynamics is correct?

Accepted Answer

The entropy of a perfectly crystalline substance at 0 K is zero.

Introduction to Thermodynamics and Kinetics in General Chemistry

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