Question

A solid is decomposed in HCl, producing a gas. The product gas took 2.31 times as long to effuse as the same amount of CO2 under the same conditions of temperature and pressure. What is the molar mass of the product gas?
Answer in units of g/mol.

Answer 1

Let's make up a rate for CO2.Let's call the rate 1 L/hr for CO2. That makes 2.31 x 1 = 2.31 L/hr for the unknown gas.
(rate CO2/rate for X) = sqrt (mm X/mm CO2) where mm stands for molar mass. Solve for X = molar mass gas X.
Post your work if you get stuck.