MULTIPLE CHOICE

Question

The volume of a dry gas is 4.00 L at 15°C and 745 torr. What volume will the gas occupy at 40°C and 700 torr?

a. 3.46 L

b. 3.92 L

c. 4.08 L

d. 4.63 L

Answer 1

Change temperatures to Kelvin, and use P1V1/T1 = P2V2/T2

(745)(4.00)/288) = (700)(V2)/(313)

V2 = 4.63 L

Answer 2

P1 V1 / T1 = P2 V2 / T2

P1 = 745 torr

P2 = 700 torr

V1 = 4.00 L

V2 = ?

T1 = 15 °C + 273 = 288 K

T2 = 40 °C + 273 = 313 K

Solve for V2

V2 = (P1 V1 T2) / (P2 T1)

= (745 torr x 4.00 L x 313 K) / (700 torr x 288 K)

= 4.63 L (answer choice D)