Question

A}. In ammounia , nitrogen and hydrogen are always present in the ratio 14:3 by mass. State the law which explains the above statement.

B}. Durin the formation of ammounia , What mass of hydrogen gas would be required to react completly with 42g of nitrogen gas ?

c}. Define atomicity . What is the atomicity of a molecule of nitrogen ?

Answer 1

a) ​According to law of definite composition, all the sample of any chemical compound has the same composition of elements by mass.

b) Formation of ammonia: N₂ + 3H₂ $\to$2NH3

1 mole of nitrogen that is 28grams of nitrogen requires 3moles of hydrogen that is 6grams of hydrogen for producing 2moles of ammonia.
hence for 1 mole of ammonia half the mass would be required. That is, 14 grams of nitrogen will require 3grams of hydrogen.
Now 42grams of nitrogen will require = (3/14)$\times$42= 9grams of hydrogen

c) Atomicity: Total number of atoms present in a molecule of an element or a substance.
Atomicity of nitrogen molecule: It is a diatomic molecule. Atomicity = 2