Question

A 3.35 gram sample of an unknown gas is found to occupy a volume of 1.64 L at a pressure of 706 mmHg and a temperature of 59 °C. Assume ideal behavior. The molar mass of the unknown gas is ___________ g/mol.

Answer 1

Answer: The molar mass of the unknown gas is 59.8 g/mol

Step-by-step explanation:

According to the ideal gas equation:-

`PV=nRT`

P= Pressure of the gas = 706 mmHg = 0.93 atm (760mmHg=1atm)

V= Volume of the gas = 1.64 L

T= Temperature of the gas = 59°C=(59+273)K=332 K (0°C = 273 K)

R= Value of gas constant = 0.0821 Latm\K mol

`n=(PV)/(RT)=(0.93* 1.64L)/(0.0821 * 332)=0.056moles`

To calculate the moles, we use the equation:

`\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}`

`0.056=\frac{3.35g}{\text {Molar mass}}`

`{\text {Molar mass}}=59.8g`

Thus the molar mass of the unknown gas is 59.8 g/mol