Vidyalelo
Chemical Engineering · Q3

Stoichiometry

Engineering and GATE · Chemical Engineering · question 3

Q3

The total number of atoms in 8.5 gm of NH3 is __________ × 1023.

A.
9.03
B.
3.01
C.
12.04
Answer
D.
6.02

Answer: Option C

Solution

Answer: Option C
Solution:
The molecular weight of NH3 is 17 g/mol (Nitrogen = 14, Hydrogen = 1 × 3 = 3).

For 8.5 grams of NH3, the number of moles is calculated as:

Moles of NH3 = 8.5 / 17 = 0.5 moles.

The total number of molecules in 0.5 moles is:

0.5 × 6.02 × 1023 molecules.

Since each molecule of NH3 contains 4 atoms (1 nitrogen and 3 hydrogen), the total number of atoms is:

0.5 × 6.02 × 1023 × 4 = 12.04 × 1023 atoms.