Q: Calculate the kinetic energy of an electron ($$m = 9.11 \times 10$$^{-31}$$ \text{ kg}) $$moving at $$1.58 \times 10^6$ \text{ m/s}.$$

$$1.14 \times 10$$^{-18}$$ \text{ J}$$

Q: A calorimeter absorbs 87.0 J as its temperature goes from 33 $$^\circC to 38.1$$ $$^\circC. $$What is its standard heat capacity?

$$17.1 \text{ J}/^\circ\text{C}$$

Q: A reaction absorbs 684.5 J of heat and raises the temperature of 15.7 g of water by 17.2 $$^\circC. $$What is the molar heat capacity?

$$2.61 \text{ J/g} \cdot ^\circ\text{C}$$

Question 1

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

Accepted Answer

Energy can be transformed between system and surroundings, but the total energy remains constant.

Question 2

A 2.0 kg object is lifted to a height of 5.0 m above the ground. What is its potential energy? (Use $$g = 9.8 	ext{ m/s}^2)$$

Accepted Answer

$$98 	ext{ J}$$

Question 3

Which process is an example of an endothermic reaction?

Accepted Answer

Ice melting

Question 4

If the temperature of a water bath goes from 25 $$^\circC to 50$$ $$^\circC$$, what can be said about the amount of heat absorbed?

Accepted Answer

It will double

Question 5

Calculate the kinetic energy of an electron ($$m = 9.11 	imes 10$$^{-31}$$ 	ext{ kg}) $$moving at $$1.58 	imes 10^6$ 	ext{ m/s}.$$

Accepted Answer

$$1.14 	imes 10$$^{-18}$$ 	ext{ J}$$

Question 6

Which of the following substances will show the greatest temperature change upon absorbing 25.0 J of heat?

Accepted Answer

250.0 g of Cu

Question 7

A sample of copper absorbs 13.5 J of heat, which increases its temperature by 25 $$^\circC. $$What is the mass (in g) of the copper sample if the specific heat capacity of copper is $$0.385 	ext{ J/g} \cdot ^\circ	ext{C}$$?

Accepted Answer

$$1.40 	ext{ g}$$

Question 8

Which of the following processes represents an exothermic reaction?

Accepted Answer

Combustion of gasoline

Question 9

What is the formula for calculating the change in internal energy ($$\Delta E) of a $$system?

Accepted Answer

$$\Delta E = q + w$$

Question 10

A reaction is carried out in a bomb calorimeter and releases 2222 kJ of energy. What type of reaction is this?

Accepted Answer

Exothermic

Question 11

Which of the following elements is found in its standard state at room temperature?

Accepted Answer

$$O_2 (g$$)$$

Question 12

What is the specific heat capacity formula for calculating the amount of heat absorbed or released?

Accepted Answer

$$q = mc\Delta T$$

Question 13

A calorimeter absorbs 87.0 J as its temperature goes from 33 $$^\circC to 38.1$$ $$^\circC. $$What is its standard heat capacity?

Accepted Answer

$$17.1 	ext{ J}/^\circ	ext{C}$$

Question 14

Which of the following statements about thermal equilibrium is correct?

Accepted Answer

At thermal equilibrium, two substances in contact have the same temperature.

Question 15

Given the reaction $$2 	ext{Mg} (s) + 	ext{O}_2 (g) ightarrow 2 	ext{MgO} (s)$$ with $$\Delta H = -1204 	ext{ kJ}$$, what is $$\Delta H$$ for $$	ext{Mg} (s) + \frac{1}{2} 	ext{O}_2 (g) ightarrow 	ext{MgO} (s)$$?

Accepted Answer

$$-602 	ext{ kJ}$$

Question 16

Which of the following is a correct application of Hess's Law?

Accepted Answer

The enthalpy change of a reaction is the sum of the enthalpy changes of the steps leading to the reaction.

Question 17

A reaction absorbs 684.5 J of heat and raises the temperature of 15.7 g of water by 17.2 $$^\circC. $$What is the molar heat capacity?

Accepted Answer

$$2.61 	ext{ J/g} \cdot ^\circ	ext{C}$$

Question 18

Which of the following statements is true about exothermic reactions?

Accepted Answer

They release heat to the surroundings.

Thermochemical Aspects of Chemical Reactions – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards