A balloon is filled with 35L of helium in the morning when the temperature is 20C. By noon the temperature has risen to 45C. What is the new volume of the balloon?

Answer: 38L

Explanation:

Initial volume of helium V1 = 35 L

Initial temperature T1 = 20°C

Convert temperature in Celsius to Kelvin

(20°C + 273 = 293K)

New volume V2 = ?

New Temperature T2 = 45°C

(45°C + 273 = 318K)

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

(V1/T1) = (V2/T2)

35L/293K = V2/318K

0.119 = V2/318K

To get V2, cross multiply

V2 = 0.119 x 318

V2 = 38L

Thus, the new volume of the balloon is 38 liters