Charles's Law Examples: 45 Problems with Answers

Start with the recap, study the fully worked examples, then use the practice problems to check your understanding of Charles's Law.

This page combines explanation, solved examples, and follow-up practice so you can move from recognition to confident problem-solving in Chemistry.

Concept Recap

Charles's law states that for a fixed amount of gas at constant pressure, volume is directly proportional to absolute temperature.

Warmer gas spreads out more when it is free to expand.

Read the full concept explanation →

How to Use These Examples

Read the first worked example with the solution open so the structure is clear.
Try the practice problems before revealing each solution.
Use the related concepts and background knowledge badges if you feel stuck.

What to Focus On

Core idea: Charles's Law starts by listing pressure, volume, temperature, amount, and which are held constant.

Common stuck point: Students often know a formula related to charles's law but skip the recognition step: Am I comparing gas variables with units and temperature in kelvin, while holding the stated variables constant? That leads to a correct-looking substitution attached to the wrong chemical model.

Sense of Study hint: Ask: Am I comparing gas variables with units and temperature in kelvin, while holding the stated variables constant?

Worked Examples

Example 1

easy

A weather balloon holds

4.0\text{ L}

of helium at

200\text{ K}

. The balloon is warmed to

300\text{ K}

at constant pressure. What is its new volume?

Answer

V_{2} = 6.0 L

First step

List the knowns:

V_1 = 4.0\text{ L}

T_1 = 200\text{ K}

T_2 = 300\text{ K}

P

constant.

See the full worked solution + why-it-works coaching

SetupKey insightWhy it worksCommon pitfallConnection

Unlock answer keys One Family plan — every worked solution, all subjects

Example 2

medium

A piston of oxygen reads

480\text{ mL}

-23\,^{\circ}\text{C}

and constant pressure. To what kelvin temperature must it be warmed for the volume to reach

720\text{ mL}

Example 3

medium

Two readings on a hot-air balloon's gas bag at constant pressure: at

290\text{ K}

the bag holds

580\text{ L}

. To make it lift more, the air is heated to

348\text{ K}

. How much larger is the volume?

Example 4

medium

A car tire on a

7\,^{\circ}\text{C}

morning has an air column of

5.60\text{ L}

at near-atmospheric pressure. After driving, the air heats to

77\,^{\circ}\text{C}

(treat pressure as roughly constant). Estimate the new volume.

Example 5

hard

1.20\text{ L}

gas sample is at

-73\,^{\circ}\text{C}

. It is heated at constant pressure until both the kelvin temperature and the volume double. What is the final Celsius temperature, and what is the final volume?

Example 6

hard

At constant pressure, a gas's volume varies linearly with Celsius temperature. Given

V = 540\text{ mL}

27\,^{\circ}\text{C}

, derive a linear equation

V = m\,t + b

in Celsius.

Example 7

hard

A scientist plots gas volume against Celsius temperature at constant pressure and extends the line. The

x

-intercept is at

-273\,^{\circ}\text{C}

. Explain what this point represents physically.

Practice Problems

Try these problems on your own first, then open the solution to compare your method.

Example 1

easy

A gas occupies

200\text{ mL}

300\text{ K}

. What is its volume at

600\text{ K}

at constant pressure?

Example 2

easy

A balloon holds

1.0\text{ L}

250\text{ K}

. Heated to

500\text{ K}

at constant pressure, what is the new volume?

Example 3

easy

Convert

27\,^{\circ}\text{C}

to Kelvin for use in Charles's law.

Example 4

easy

A gas at

400\text{ K}

has volume

800\text{ mL}

. Cooled to

200\text{ K}

, what is its volume at constant pressure?

Example 5

easy

As a fixed gas sample is heated at constant pressure, does its volume increase or decrease?

Example 6

easy

500\text{ mL}

gas at

300\text{ K}

is warmed to

450\text{ K}

at constant pressure. New volume?

Example 7

easy

Which quantities must stay constant for Charles's law to apply?

Example 8

easy

A gas at

100\text{ K}

occupies

50\text{ mL}

. What volume at

300\text{ K}

, constant pressure?

Example 9

medium

A gas occupies

300\text{ mL}

27\,^{\circ}\text{C}

. What is its volume at

127\,^{\circ}\text{C}

at constant pressure?

Example 10

medium

A gas expands from

250\text{ mL}

1000\text{ mL}

at constant pressure starting at

200\text{ K}

. Final temperature?

Example 11

medium

A balloon at

300\text{ K}

has volume

2.4\text{ L}

. To shrink it to

1.6\text{ L}

at constant pressure, what temperature is needed?

Example 12

medium

A gas occupies

600\text{ mL}

400\text{ K}

. At what Celsius temperature is its volume

450\text{ mL}

at constant pressure?

Example 13

medium

Two volume-temperature data points for a gas at constant pressure are

(V_1,T_1)=(150\text{ mL},250\text{ K})

and

V_2=300\text{ mL}

. Find

T_2

Example 14

medium

1.5\text{ L}

gas at

250\text{ K}

is heated to

350\text{ K}

at constant pressure. By how many liters does it expand?

Example 15

medium

At constant pressure a gas is cooled until its volume falls from

900\text{ mL}

600\text{ mL}

. If it started at

360\text{ K}

, what is the final temperature in Celsius?

Example 16

medium

A gas thermometer reads volume

220\text{ mL}

at the known point

275\text{ K}

. Later it reads

264\text{ mL}

at constant pressure. What temperature does this indicate?

Example 17

medium

A gas at

320\text{ K}

fills

480\text{ mL}

. What temperature triples the original volume at constant pressure?

Example 18

challenge

A gas at

-23\,^{\circ}\text{C}

occupies

500\text{ mL}

. Find the Celsius temperature at which its volume is

750\text{ mL}

at constant pressure.

Example 19

challenge

Two gas samples at constant pressure: sample A goes

300\text{ mL}\to 400\text{ mL}

T

rises from

T

T+100

. Find

T

in Kelvin.

Example 20

challenge

A gas at

400\text{ K}

and

750\text{ mL}

is cooled at constant pressure. Extrapolating linearly, at what Celsius temperature would its volume reach

0

Example 21

easy

A nitrogen sample occupies

360\text{ mL}

240\text{ K}

. Find its volume at

480\text{ K}

, pressure held constant.

Example 22

easy

A gas sample of

120\text{ mL}

150\text{ K}

is heated to

450\text{ K}

at constant pressure. New volume?

Example 23

easy

A gas at

500\text{ K}

occupies

1000\text{ mL}

. Cool it to

250\text{ K}

at constant pressure. What is the new volume?

Example 24

easy

A gas occupies

250\text{ mL}

100\text{ K}

. Find its volume at

400\text{ K}

at constant pressure.

Example 25

medium

A neon sample occupies

620\text{ mL}

27\,^{\circ}\text{C}

. Find its volume at

327\,^{\circ}\text{C}

at constant pressure.

Example 26

medium

At constant pressure, a

750\text{ mL}

gas at

375\text{ K}

is cooled to

225\text{ K}

. By how many milliliters does it shrink?

Example 27

medium

A balloon holds

1.8\text{ L}

300\text{ K}

and constant pressure. What Celsius temperature halves the volume?

Example 28

medium

2.40\text{ L}

argon sample at

300\text{ K}

is heated at constant pressure until it reaches

3.60\text{ L}

. Find the new kelvin temperature.

Example 29

medium

A gas at

T_1 = 250\text{ K}

has volume

V_1

. After warming at constant pressure to

T_2

, the volume is

1.20\,V_1

. Find

T_2

in Celsius.

Example 30

medium

A gas occupies

720\text{ mL}

360\text{ K}

. Find its volume when cooled to

-33\,^{\circ}\text{C}

at constant pressure.

Example 31

medium

A gas at

200\text{ K}

and

0.60\text{ L}

is warmed at constant pressure until it reaches

0.90\text{ L}

. Find the new temperature in Celsius.

Example 32

medium

At constant pressure, a gas's volume goes from

0.40\text{ L}

0.50\text{ L}

. If the initial temperature was

320\text{ K}

, what is the final temperature?

Example 33

hard

A balloon at

17\,^{\circ}\text{C}

holds

2.90\text{ L}

at constant pressure. What Celsius temperature gives a volume of

5.00\text{ L}

Example 34

hard

A student claims a gas at

20\,^{\circ}\text{C}

heated to

40\,^{\circ}\text{C}

at constant pressure doubles in volume. Find the actual volume ratio

V_2/V_1

Example 35

hard

Two trials of a gas at constant pressure give

(V, t)

pairs

(220\text{ mL}, -23\,^{\circ}\text{C})

and

(V_2, 127\,^{\circ}\text{C})

. Find

V_2

Example 36

hard

A gas at

250\text{ K}

occupies

800\text{ mL}

. It is cooled at constant pressure until its volume is reduced by

25\%

. Find the new temperature in kelvin.

Example 37

hard

A sealed flexible bag of gas is at

310\text{ K}

with volume

620\text{ mL}

1\text{ atm}

. The pressure is increased so the bag's pressure rises 25% while temperature also rises to

372\text{ K}

. Is Charles's law sufficient to predict the new volume?

Example 38

challenge

A research balloon of ideal gas at

295\text{ K}

and constant pressure is to deliver

9.00\text{ L}

of payload-space at

354\text{ K}

. What initial volume must the balloon hold at

295\text{ K}

so that no excess gas is needed?

← Back to Charles's Law Formula Explained Practice Mode

Related Concepts

Gas Laws Avogadro's Law

Background Knowledge

These ideas may be useful before you work through the harder examples.

gas laws