Question

The number of molecules in 4.25 gm ammonia is

(A) 1.0 x 10²³

(B) 1.5 x 10²³

(C) 2.0 x 10²³

(D) 2.5 x 10²³

Answer 1

Correct option is (B) 1.5 x 10²³

As 17 g of NH₃ has 1 mol.

Number of moles in 4.25g = \(\frac {4.25}{17}\)

Number of molecules = \(\frac{4.25}{17} \times 6.023 \times 10^{23}= 1.5 \times 10^{23}\)