Question

A 0.49 g sample of an ideal gas in a 200 ml container at 26 °C exerts a pressure of 0.98 atm. What is the molar mass of this gas (in g/mol)? NOTE: The molar mass you calculate may not correspond to a real-life gas (don't try to identify the gas). You have 5 attempts at this question. Answer: Check

Answer 1

PV = nRT

where, P = pressure = 0.98 atm

V = 200 mL = 0.200 L

n = number of moles

R = Gas constant

T = temperature = 26 + 273 = 299 K

0.98 * 0.200 = n * 0.0821 * 299

0.196 = n * 24.5

n = 0.196 / 24.5 = 0.00800 mole

number of moles = mass / molar mass

0.008 mole = 0.49 g / molar mass

molar mass = 0.49 g / 0.008 mole = 61.3 g/mol

Therefore, molar mass of gas = 61.3 g/mol