Question

1. A balloon is filled with He gas to a volume of 2.10 L at 35 °C. The balloon is placed in liquid nitrogen until its temperature reaches –196 °C. Assuming the pressure remains constant, what is the volume of the cooled balloon?

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     2.   Gaseous chlorine is held in two separate containers at identical temperature and pressure. The volume of container 1 is 1.30 L, and it contains 6.70 mol of the gas. The volume of container 2 is 2.33 L. How many moles of the gas are in container 2?

Show all work please.

Answer 1

1.

Using the Charle's Law you can do the calculations:

Charles Laws equation:  V1/T1 = V2/T2

First you have to conver the starting and ending temperature to Kelvin

T1= 35°C +273.15= 308 K
T2= -196°C + 273.15 = 77 K

V1=2.10 L
V2= x

Now you use this number into Charle's Law equation

2.10 L/ 308 K = x / 77 K

cross multiply

160 L*K = 308 K *x

divide 308 K over

x=0.52 L

The cooled balloon has a volume of 0.52 Liters

2.

At constant temperature and pressure, the amount of substance is proportional to the volume.
6.7 mol /1.3 L = x /2.2 L
from this you can claculate the x value:

x= 6.7*2.2/1.3 mol = 11.3 mol

In the container 2 are 11.3 moles of Chlorine