Question

Pressure of 1 gm of an ideal gas A at 27°C is found to be 2 bar when 2 gms of another ideal gas B is introduced at same temperature the pressure becomes 3 bar find relationship between their molecular masses

Answer 1

Answer:

Pressure of 1 g of an ideal gas A at 27 °C is found to be 2 bar. When 2 g of another ideal gas B is introduced in the same flask at same temperature the pressure becomes 3 bar.

Answer 2

The relationship between their molecular masses is M' = 4M

Explanation:

Let the molar mass and pressure of gas A be M and P respectively

Let the molar mass and pressure of gas B be M' and P' respectively

From question, number of moles of A be 1/M

From question, number of moles of B be 1/M'

From question, P = 2 bar

From question, P + P' = 3 bar

∴ P' = 1 bar

Now, the idea gas equation from gas A is:

PV = nRT → (equation 1)

The idea gas equation from gas B is:

P'V = n'RT → (equation 2)

On dividing equation (1) by (2), we get,

P/P' = n/n' = (1 × M)/(2 × M') = M/2M'

M/M' = 2P/P'

On substituting the values, we get,

M/M' = (2 × 2)/1 = 4

∴ M = 4M'