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

$$q = 100 \times 4.184 \times (50-20) = 12,552 \ \mathrm{J}$$

$$c = \frac{500}{50 \times (45-25)} = 0.5 \ \mathrm{J/g^\circ C}$$

Question 1

Which of the following best describes the process shown in the image of molten metal being poured in a foundry?

Accepted Answer

A physical change, because the metal changes from solid to liquid without altering its composition.

Question 2

Which of the following is a chemical property?

Accepted Answer

Ability to react with oxygen

Question 3

Which equation correctly represents the relationship between heat, mass, specific heat, and temperature change?

Accepted Answer

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

Question 4

A student heats 100 g of water from 20°C to 50°C. How much heat is absorbed? (Specific heat of water = $$4.184 \ \mathrm{J/g^\circ C})$$

Accepted Answer

$$q = 100 	imes 4.184 	imes (50-20) = 12,552 \ \mathrm{J}$$

Question 5

Which of the following is NOT a physical property?

Accepted Answer

Ability to decompose in acid

Question 6

Which of the following is an example of a chemical change?

Accepted Answer

Burning wood

Question 7

A 50 g sample of an unknown metal absorbs 500 J of heat, raising its temperature from 25°C to 45°C. What is the specific heat of the metal?

Accepted Answer

$$c = \frac{500}{50 	imes (45-25)} = 0.5 \ \mathrm{J/g^\circ C}$$

Question 8

Which statement best describes the Law of Conservation of Energy?

Accepted Answer

Energy can be neither created nor destroyed, only converted from one form to another.

Question 9

Which of the following is a source of energy that is NOT derived from the sun?

Accepted Answer

Nuclear

Question 10

Which of the following best describes kinetic energy?

Accepted Answer

Energy due to motion

Question 11

Which of the following processes is a physical change?

Accepted Answer

Evaporation of alcohol

Question 12

A chemical equation is used to represent:

Accepted Answer

A chemical change only

Question 13

Which of the following best explains why water has a high specific heat?

Accepted Answer

Water molecules form strong hydrogen bonds.

Question 14

Which of the following is true about the energy required to heat two beakers of water, one with twice the mass of the other, by the same temperature?

Accepted Answer

The beaker with twice the mass requires twice the heat.

Question 15

Which of the following is a correct unit for specific heat?

Accepted Answer

$$\mathrm{J/g^\circ C}$$

Question 16

Which of the following is a real-world example of energy conversion from potential to kinetic energy?

Accepted Answer

A diver jumping off a diving board

Question 17

Which of the following is the main component of natural gas?

Accepted Answer

Methane ($$\mathrm{CH_4$})$$

Question 18

Which of the following best describes a physical property?

Accepted Answer

The boiling point of ethanol

Question 19

Which of the following is an example of energy being absorbed during a chemical change?

Accepted Answer

Photosynthesis in plants

Question 20

Which of the following is a renewable energy source?

Accepted Answer

Wind

Chapter 4: Properties of Matter – Study Notes for Introduction to Chemistry

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