At its boiling point (280°c) and at atmospheric pressure, phosphorus gas has a density of 2.7 g l–1 . under the same conditions, nitrogen gas has a density of 0.62 g l–1 . how many atoms of phosphorus are there in one phosphorus molecule under these conditions?

4 atoms of phosphorus are there in one phosphorus molecule.

Explanation:

Density of phosphorus gas,d = 2.7 g/L

Temperature of the gas = T = 280°C = 553.15 K

Molar mass of phosphorus gas = M

Pressure of the gas ,P= 1 atm

...(1)

Density of nitrogen gas,d' = 0.62 g/L

Temperature of the gas = T'= 280°C = 553.15 K

Molar mass of nitrogen gas = M' = 28 g/mol

Pressure of the gas ,P' = 1 atm

...(2)

Dividing (1) and (2):

M = 121.93 g/mol

Atomic mass of 1 phosphorus atom = 31 g/mol

Number of phosphorus atom in phosphorus gas:

4 atoms of phosphorus are there in one phosphorus molecule.

the product of the pressure and volume is also constant