Q: Which equation is used to calculate the heat absorbed or released by a substance?

$$q = m \times c \times \Delta T$$

Q: How much heat (in joules) is required to raise the temperature of 50.0 g of water from 20.0°C to 30.0°C? (Specific heat of water = $$4.18 \ \text{J/g} \cdot \text{°C}). $$Round your answer to the correct number of significant figures.

$$2.09 \times 10^3$ \ \text{J}$$

Q: If a sample of metal requires 500 J of heat to raise its temperature by 10°C and has a mass of 25 g, what is its specific heat capacity? Round your answer to the correct number of significant figures.

$$2.0 \ \text{J/g} \cdot \text{°C}$$

Question 1

Which of the following best describes the difference between kinetic and potential energy in a chemical system?

Accepted Answer

Kinetic energy is the energy of motion of particles, while potential energy is stored in chemical bonds.

Question 2

Which of the following is NOT a common unit of energy?

Accepted Answer

Watt (W)

Question 3

Convert 250 calories to joules. (1 cal = 4.184 J). Round your answer to the correct number of significant figures.

Accepted Answer

$$1046 \ 	ext{J}$$

Question 4

Which of the following best defines an exothermic reaction?

Accepted Answer

A reaction that releases heat to the surroundings.

Question 5

Which of the following is an example of an endothermic process?

Accepted Answer

Melting of ice in a glass of water.

Question 6

Which statement correctly explains the difference between exothermic and endothermic reactions?

Accepted Answer

Exothermic reactions release energy, while endothermic reactions absorb energy.

Question 7

Which of the following lists the three common units of temperature?

Accepted Answer

Kelvin, Celsius, Fahrenheit

Question 8

How are temperature and the average kinetic energy of particles in a substance related?

Accepted Answer

Temperature is directly proportional to the average kinetic energy of the particles.

Question 9

Which of the following best describes how temperature relates to the motion of particles in matter?

Accepted Answer

As temperature increases, particle motion increases.

Question 10

Convert 37.0°C to Kelvin. (K = °C + 273.15). Round your answer to the correct number of significant figures.

Accepted Answer

$$310.2 \ 	ext{K}$$

Question 11

Which of the following best defines specific heat capacity?

Accepted Answer

The amount of heat required to raise the temperature of 1 gram of a substance by 1°C.

Question 12

Which equation is used to calculate the heat absorbed or released by a substance?

Accepted Answer

$$q = m 	imes c 	imes \Delta T$$

Question 13

How much heat (in joules) is required to raise the temperature of 50.0 g of water from 20.0°C to 30.0°C? (Specific heat of water = $$4.18 \ 	ext{J/g} \cdot 	ext{°C}). $$Round your answer to the correct number of significant figures.

Accepted Answer

$$2.09 	imes 10^3$ \ 	ext{J}$$

Question 14

A chemical reaction in a hand warmer releases heat. Which term best describes this reaction?

Accepted Answer

Exothermic

Question 15

Which of the following is a real-life example of an endothermic reaction?

Accepted Answer

Photosynthesis in plants.

Question 16

If a sample of metal requires 500 J of heat to raise its temperature by 10°C and has a mass of 25 g, what is its specific heat capacity? Round your answer to the correct number of significant figures.

Accepted Answer

$$2.0 \ 	ext{J/g} \cdot 	ext{°C}$$

Question 17

Which of the following statements about energy unit conversions is correct?

Accepted Answer

1 calorie is equal to 4.184 joules.

Question 18

A patient’s fever is measured at 102.2°F. What is this temperature in Celsius? (Use $$°C = (°F - 32) 	imes \frac{5}{9}). $$Round your answer to the correct number of significant figures.

Accepted Answer

$$39.0 \ ^\circ 	ext{C}$$

Question 19

Which of the following best explains why metals feel colder than wood at the same temperature?

Accepted Answer

Metals conduct heat away from your hand more quickly due to higher thermal conductivity.

Question 20

A 100.0 g sample of ethanol absorbs 8360 J of heat, causing its temperature to rise from 25.0°C to 45.0°C. What is the specific heat capacity of ethanol? Round your answer to the correct number of significant figures.

Accepted Answer

$$0.418 \ 	ext{J/g} \cdot 	ext{°C}$$

Chemistry Chapter 3 Part 3: Energy, Temperature, and Heat

Guida di studio - Domande di pratica

Study guide - Flashcard