Question

what is molar mass of a gas if 0.0494g of the gas occupies a vol of 0.153 L at temperature of 26C and a pressure of 0.998 atm?

Answer 1

`\large \boxed{\text{7.94 g/mol}}`

Step-by-step explanation:

We can use the Ideal Gas Law to solve this problem

pV = nRT

Data:

p = 0.998 atm

V = 0.153 L

T = 26 °C

m = 0.0494 g

1. Convert temperature to kelvins

T = (26 + 273.15) K = 299.15 K

2. Calculate the number of moles

`\text{0.998 atm} *\text{0.153 L} = n * \text{0.082 06 L}\cdot\text{atm}\cdot\text{K}^(-1)\text{mol}^(-1)* \text{299.15 K}\\\\0.1527 = n * \text{24.55 mol}^(-1)\\\\n = \frac{0.1527}{\text{24.55 mol}^(-1)} = 6.220 * 10^(-3) \text{ mol}`

3. Calculate the molar mass

`\text{Molar mass} = \frac{\text{mass}}{\text{moles}}\\\\M = (m)/(n)\\\\M = \frac{\text{0.0494 g}}{6.220 * 10^(-3) \text{ mol}}\\\\M = \textbf{7.94 g/mol}\\\text{The molar mass of the gas is } \large \boxed{\textbf{7.94 g/mol}}`