Q: A student records the temperature of boiling water as 100°C. What is this temperature in Fahrenheit?

$$F = (100 \times \frac{9}{5}) + 32 = 212^\circ F$$

Q: A sample of water is heated from 20°C to 80°C. If the mass of water is 50.0 g and the specific heat capacity is $$4.18\ \mathrm{J/g\cdot ^\circ C}$$, how much heat ($$q) is $$absorbed?

$$q = 50.0 \times 4.18 \times (80 - 20) = 12,540\ \mathrm{J}$$

Q: A student needs to convert 0.250 km to meters. What is the correct conversion?

$$0.250\ \mathrm{km} \times 1000\ \mathrm{m/km} = 250\ \mathrm{m}$$

Q: A metal sample with mass 25.0 g absorbs 200.0 J of heat, causing its temperature to rise from 20.0°C to 28.0°C. What is the specific heat capacity ($$c) of $$the metal?

$$c = \frac{q}{m \Delta T} = \frac{200.0}{25.0 \times (28.0 - 20.0)} = 1.00\ \mathrm{J/g\cdot ^\circ C}$$

Question 1

Which of the following best describes a heterogeneous mixture?

Accepted Answer

A mixture in which the composition is not uniform and different parts can be visually distinguished.

Question 2

A student measures the mass of a liquid as 12.30 g and its volume as 8.2 mL. What is the density of the liquid, reported with the correct number of significant digits?

Accepted Answer

$$\frac{12.30\ \mathrm{g}}{8.2\ \mathrm{mL}} = 1.5\ \mathrm{g/mL}$$

Question 3

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

Accepted Answer

Melting of ice into water.

Question 4

Which prefix represents $$10^{-3} in $$the metric system?

Accepted Answer

milli-

Question 5

A chemical reaction occurs in a closed container. The total mass of the reactants is 25.0 g. After the reaction, the total mass of the products is measured as 24.8 g. Which law does this scenario violate?

Accepted Answer

Law of Conservation of Mass

Question 6

Which of the following is a homogeneous mixture?

Accepted Answer

Air in a classroom.

Question 7

A student records the temperature of boiling water as 100°C. What is this temperature in Fahrenheit?

Accepted Answer

$$F = (100 	imes \frac{9}{5}) + 32 = 212^\circ F$$

Question 8

Which statement about the Law of Conservation of Energy is correct?

Accepted Answer

Energy can change forms but cannot be created or destroyed.

Question 9

How many significant digits are in the measurement 0.00450 kg?

Accepted Answer

3

Question 10

Which of the following best describes a compound?

Accepted Answer

A substance composed of two or more elements chemically combined in fixed proportions.

Question 11

A sample of water is heated from 20°C to 80°C. If the mass of water is 50.0 g and the specific heat capacity is $$4.18\ \mathrm{J/g\cdot ^\circ C}$$, how much heat ($$q) is $$absorbed?

Accepted Answer

$$q = 50.0 	imes 4.18 	imes (80 - 20) = 12,540\ \mathrm{J}$$

Question 12

Which of the following is NOT a characteristic of gases?

Accepted Answer

Definite shape

Question 13

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

Accepted Answer

Cooking an egg

Question 14

A student needs to convert 0.250 km to meters. What is the correct conversion?

Accepted Answer

$$0.250\ \mathrm{km} 	imes 1000\ \mathrm{m/km} = 250\ \mathrm{m}$$

Question 15

Which of the following best describes a chemical property?

Accepted Answer

Ability to react with oxygen

Question 16

A student adds 2.00 g of sodium chloride to 100.0 mL of water and stirs until dissolved. What type of mixture is formed?

Accepted Answer

Homogeneous mixture (solution)

Question 17

Which of the following measurements has the greatest uncertainty?

Accepted Answer

12 g

Question 18

Which of the following is the correct scientific notation for 0.00056?

Accepted Answer

$$5.6 	imes 10$$^{-4}$$

Question 19

A chemical equation shows: $$2\ \mathrm{H}_2 + \mathrm{O}_2 \rightarrow 2\ \mathrm{H}_2\mathrm{O}. If $$you start with 4.0 g of $$\mathrm{H}_2$$ and 32.0 g of $$\mathrm{O}_2$$, what is the total mass of water produced?

Accepted Answer

36.0 g

Question 20

A metal sample with mass 25.0 g absorbs 200.0 J of heat, causing its temperature to rise from 20.0°C to 28.0°C. What is the specific heat capacity ($$c) of $$the metal?

Accepted Answer

$$c = \frac{q}{m \Delta T} = \frac{200.0}{25.0 	imes (28.0 - 20.0)} = 1.00\ \mathrm{J/g\cdot ^\circ C}$$

Introduction to Chemistry: Measurement, Matter, and Energy Study Guide

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