Simple Gas Laws & Partial Pressure

1. A dramatic classroom demonstration involves cooling a balloon from room temperature (300 K) to liquid nitrogen temperature (77 K).

A. If the initial volume of the balloon is 2.7 L, what will its volume be after it cools? (Assume constant pressure.)

V2=____________L

2. A gas mixture contains 83% nitrogen and 17% oxygen.
If the total pressure is 1.20 atm what are the partial pressures of each component?
(Express your answers using two significant figures. Enter your answers numerically separated by a comma.)

A. PN2, PO2=________________atm

V1(P1)=V2(P2)
V1(P1)/P2=V2
2.7L(300K)/77K=V2
1.05L=V2

Pi=Xi(P) Xi=ni/n
PN2=1.02atm
PO2=0.18atm