Question

What is the ratio between masses of Nitrogen and Hydrogen in $N{H_3}$ ?
[Atomic mass of $H = 1u,O = 16u,N = 14u$ ]

Answer 1

Hint : To answer this question we need to know the molar masses of the elements forming the given compound. For calculating the mass ratio of Nitrogen and Hydrogen in ammonia we will calculate the total mass each element is contributing to the total molar mass of ammonia.

Complete Step By Step Answer:
Ammonia consists of one atom of nitrogen and three atoms of hydrogen. It is also known as Hydrogen Nitride.
Calculating molar mass contributed by nitrogen and hydrogen to the molar mass of ammonia
$1 \times 14 = 14$ , ammonia contains one atom of nitrogen and molar mass of nitrogen is $14u$
$3 \times 1 = 3$ , ammonia contains three atoms of hydrogen, and the molar mass of hydrogen is $1u$
Now dividing the molar mass contributed by nitrogen and hydrogen
we get, $\dfrac{{14}}{3}$
we get the mass ratio, $14:3$
So, nitrogen and hydrogen are present in ratio $14:3$ by mass in ammonia.

Additional Information:
Atomic mass unit (u) is defined as the mass equal to one-twelfth the mass of a carbon twelve atom. Mass of any isotope of any element is expressed in terms of carbon twelve standards. Ammonia is a colorless gas with distinct characteristics of a pungent smell.

Note :
Carefully observe the chemical formula of the given compound to find out the number of atoms of each element in the compound because we have to calculate the total mass contributed by each element in the compound then only our mass ratio will be correct. If we divide only the molar mass of elements that may not be the answer if an element has multiple atoms in the compound.