Question

What is the molecular weight (g/mol) of a gas if 25.6g of the gas occupies 1.32L at standard pressure and 273K. Show the calculation.

Answer 1

433.9 g/mol

Step-by-step explanation:

The following data were obtained from the question:

Mass of gas = 25.6 g

Volume (V) = 1.32 L

Pressure (P) = stp = 1 atm

Temperature (T) = 273 K

Molecular weight =?

Next, we shall determine the number of mole of the gas. This is illustrated below:

Volume (V) = 1.32 L

Pressure (P) = stp = 1 atm

Temperature (T) = 273 K

Gas constant (R) = 0.0821 atm.L/Kmol

Number of mole (n) =.?

PV = nRT

1 × 1.32 = n × 0.0821 × 273

1.32 = n × 22.4133

Divide both side by 22.4133

n = 1.32 / 22.4133

n = 0.059 mole

Finally, we shall determine the molecular weight of the gas. This can be obtained as follow:

Mass of gas = 25.6 g

Number of mole of gas = n = 0.059 mole

Molecular weight of gas =.?

Molecular weight = mass /mole

Molecular weight of gas = 25.6 / 0.059

Molecular weight of gas = 433.9 g/mol