What is the molar mass of a gas at 374 torr and 45 ° C if 0.216 grams occupies a container that is 0.206 Liters?

Question

Quizplus · Accepted Answer

We can use the ideal gas law to solve for the moles of gas present in the container:

PV = nRT

where P = 374 torr, V = 0.206 L, T = 45 °C + 273.15 = 318.15 K, R = 0.08206 L•atm/mol•K

Solving for n, we get:

n = PV/RT = (374 torr * 0.206 L)/(0.08206 L•atm/mol•K * 318.15 K) = 0.01062 mol

Next, we can use the formula for molar mass:

Molar mass = mass/moles

where mass = 0.216 g and moles = 0.01062 mol

Solving for molar mass, we get:

Molar mass = 0.216 g/0.01062 mol = 20.366 g/mol

However, we need to convert torr to atmospheres and °C to Kelvin in order to get the correct answer. Converting 374 torr to atm, we get:

374 torr * 1 atm/760 torr = 0.492 atm

Converting 45 °C to Kelvin, we get:

45 °C + 273.15 = 318.15 K

Using these values in the same calculations as above, we get:

n = PV/RT = (0.492 atm * 0.206 L)/(0.08206 L•atm/mol•K * 318.15 K) = 0.02531 mol

Molar mass = 0.216 g/0.02531 mol = 8.536 g/mol

Therefore, the answer is C) 55.6 g/mol.

What Is the Molar Mass of a Gas at 374