KnowledgeBoat Logo
|

Chemistry

(a) Calculate the number of moles and the number of molecules present in 1.4 g of ethylene gas. What is the volume occupied by the same amount of ethylene?

(b) What is the vapour density of ethylene?

Mole Concept

20 Likes

Answer

Gram molecular mass of C2H4
= 2(12) + 4(1)
= 24 + 4 = 28 g

As,

28 g of C2H4 = 1 mole
∴ 1.4 g of C2H4 = 128\dfrac{1}{28} x 1.4 = 0.05 moles

1 mole = 6 × 1023 molecules
∴ 0.05 moles = 6 × 1023 x 0.05 = 3 x 1022 molecules

Hence, no. of moles is 0.05 and no. of molecules is 3 x 1022.

Vol. occupied by 1 mole = 22.4 lit
∴ Vol. occupied by 0.05 moles = 22.4 x 0.05 = 1.12 lit.

Hence, vol. occupied is 1.12 lit

(b)
Vapour density=Molecular weight2=282=14\text{Vapour density} = \dfrac{\text{Molecular weight}}{2} = \dfrac{28}{2} = 14

Hence, vapour density is 14

Answered By

3 Likes

Related Questions