Question

The Molar mass(M.w) in g/mol of 6.3 grams of an ideal gas that placed in 5.0 L tank at ST

P( 273 K, 1 atm) is? The identity of the gas is ?
32 g/mol, O2
71 g/mol, C12
28 g/mol, N2
16 g/mol, CH4

Answer 1

28 g/mol, N2

Step-by-step explanation:

Given data:

Volume of gas = 5.0 L

Mass of gas = 6.3 g

Pressure = 1 atm

Temperature = 273 K

Molar mass of gas = ?

Solution:

We will calculate the density first.

d = mass/ volume

d = 6.3 g/ 5.0 L

d = 1.26 g/L

Molar mass:

d = PM/RT

M = dRT/P

M = 1.26 g/L× 0.0821 atm.L/mol.K × 273 K/ 1 atm

M = 28 g/mol

Molar mass of N₂ is 28 g/mol thus given gas is N₂.