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## Homework Statement

Use the data:

**P/bar**

a: 0.1000

b: 0.5000

c: 1.000

d: 1.01325

e: 2.000

*vs.*

**density/(g/L)**

a: 0.1771

b: 0.8909

c: 1.796

d: 1.820

e: 3.652

...for an unknown gas at 300K to determine the molecular mass of the gas...

## Homework Equations

PV = nRT (b/c of very low pressure)

## The Attempt at a Solution

..so, first I plotted the data on a graph, and it seemed like a linear line....considering Pressure is very low, I assumed ideal gas law, as in PV = nRT where n = mass/(molecular mass):

PV = (mass/mm)RT --> mm = (mass/V)(RT/P) = (density)*RT/P...so, I chose one middle data point (c), where:

density = 1.796 g/L

P = 1bar= 0.9869 atm

in addition to given values:

R = 0.082058 L*atm/(mol*K)

T= 300K

and I got mm = 44.80g/mol, which is not the same as 44.10 on the back of the textbook....could someone hint where I made the mistake?