How many atoms are there in 4.25 g of NH3 ?

Question

How many atoms are there in 4.25 g of NH3 ? (A)  6 × 1023 (B)  1.5 × 1023 (C) 3.4 × 1023 (D)  1 × 1023

Tardigrade Admin · Accepted Answer

The no. of molecules =( text Given mass / text Molar mass ) × NA =(4 ⋅ 25/17) × 6 ⋅ 022 × 1023 =1.5055 × 1023 One molecules of NH 3 has 4 atom. Hence no. of atoms =1 ⋅ 5055 × 1023 × 4 =6 ⋅ 022 × 1023

Q. How many atoms are there in $4.25 g$ of $N H_{3}$ ?

$6 \times 1 0^{23}$

$1.5 \times 1 0^{23}$

$3.4 \times 1 0^{23}$

$1 \times 1 0^{23}$

The no. of molecules
$= \frac{Given mass}{Molar mass} \times N A = \frac{4 \cdot 25}{17} \times 6 \cdot 022 \times 1 0^{23}$
$= 1.5055 \times 1 0^{23}$
One molecules of $N H_{3}$ has 4 atom.
Hence no. of atoms $= 1 \cdot 5055 \times 1 0^{23} \times 4$
$= 6 \cdot 022 \times 1 0^{23}$

Q. How many atoms are there in 4.25g of NH3​ ?

6×1023

1.5×1023

3.4×1023

1×1023