5.00 L of a gas is collected at 100K and then allowed to expand to 20.0 L. What must the new temperature

be in order to maintain the same pressure?

A. 400 °C

B. 127 °C

C. 223 °C

D. 627°C

Answer: Option B) 127 °C

Explanation:

Initial volume of gas V1 = 5.00 L

Initial temperature of gas T1 = 100K

New volume of gas V2 = 20.0 L

new temperature of gas T2 = ?

Since volume and temperature are involved while pressure is constant, apply the formula for Charles law

V1/T1 = V2/T2

5.00 L/100K = 20.0 L/T2

cross multiply

5.00 x T2 = 100 x 20.0

5.00T2 = 2000

T2 = 2000/5.00

T2 = 400K

Convert temperature in Kelvin to Celsius

(400K - 273) = 127°C

Thus, the new temperature of the gas is 127°C