Question

A sample of a gas in a cylindrical chamber with a movable piston occupied a volume of 1.40 liters when the pressure was 768 torr and the temperature was 26.9 C. The volume of the system was readjusted to 2.16 liters by changing the temperature while the load on the piston was kept constant to keep the pressure in the system constant. What was the new? Assume ideality A gas sample containing 0.2820 moles of a compound is trapped in a vessel at 25.2 C and 642.0 torr. What is the volume of the vessel? Assume ideality. A sample of a gas occupies a volume of 1.820 liters at STP. What pressure would be the new pressure if the gas were transferred to a 1.425 liter vessel at 25.2 C? Assume ideality.

Answer 1

1)

Given:

Ti = 26.9 oC

= (26.9+273) K

= 299.9 K

Vi = 1.40 L

Vf = 2.16 L

use:

Vi/Ti = Vf/Tf

1.4 L / 299.9 K = 2.16 L / Tf

Tf = 463 K

Tf = (463 - 273) oC

Tf = 190 oC

Answer: 190 oC

2)

Given:

P = 642.0 torr

= (642.0/760) atm

= 0.8447 atm

n = 0.2820 mol

T = 25.2 oC

= (25.2+273) K

= 298.2 K

use:

P * V = n*R*T

0.8447 atm * V = 0.282 mol* 0.08206 atm.L/mol.K * 298.2 K

V = 8.169 L

Answer: 8.17 L

Only 1 question at a time please