Question

A 515cm^3 flask contains 0.460 g of a gas at a pressure of 153 kPa and a temperature of 322K. What is the molecular mass of this gas

Answer 1

Molecular mass,
`M=28.89\ \text{g/mol}`

Step-by-step explanation:

Given that,

Mass of gas, m = 0.46 g

Volume of the container, V = 515 cm^3

Pressure, P = 153 kPa

Temperature, T = 322 K

We need to find the molecular mass of this gas. We know that,

PV =nRT

n = no of moles

`n=(PV)/(RT)\\\\n=\frac{153\ kPa* 0.515\ L}{8.31447\ LkPaK^(-1){mol^(-1)}* (322+273)\ K }\\\\n=0.01592\ \text{moles}`

No of moles = mass/molecular mass

Let molecular mass is M

`M=(m)/(n)\\\\M=(0.46)/(0.01592)\\\\M=28.89\ \text{g/mol}`

So, the molecular mass of this gas is
`28.89\ \text{g/mol}`