Question

Calculate the number of molecules in 51g of NH3​

Answer 1

Answer:

Step-by-step explanation:no. Of mole = mole ×avagado no.

=Given mass/molar mass ×avagado no.

= 51g/17g× 6.022×10^23

=18.066×10^23

=1.8066×10^24

Answer 2

Given:

51 grams of ammonia.

To find:

We have to find the number of molecules.

Solution:

The chemical formula of ammonia is $NH_3$.

The atomic weight of the N atom is 14 grams and the atomic weight of the H atom is 1 gram.

Thus, the molecular weight of ammonia is 14+1×3=17 grams.

Thus we can write-

17 grams of ammonia has $6.022×10^{23}$ number of molecules.

51 grams of ammonia has $6.022×10^{23}×51/17=18.066×10^{23}$ number of molecules.

51 grams of ammonia has $18.066×10^{23}$ number of molecules.