What is the molar mass of 81.50 g of gas exerting a pressure of 1.75 ATM on the walls of a pressure or 1.27 ATM on the walls of 4.92 L container of 307 k?

Here, we may apply the equation of state for an ideal gas, which is:

PV = nRT

We may substitute the number of moles, n, with:

moles = mass / molecular mass

PV = mRT/Mr

Mr = (mRT) / PV

Substituting the values:

Mr = (81.5 * 0.082 * 307) / (1.75 * 4.92)

Mr = 238.3

The molar mass of the gas is 238.3 grams per mole.