Question

2.

How many molecules are in 36 g of ammonium (NH4)?
a. 3.01 x 1023 molecules
b. 6.02 x 1023 molecules
C. 1.2 x 1024 molecules
d. 1.8 x 1024 molecules

Answer 1

b. 6.02 x 1023 molecules

Step-by-step explanation:

The formula mass of ammonia is 14 + 1 × 3 = 17.

The number of moles in 27.6g ammonia is 27.6 ÷ 17 = 1.62 mol.

A mole is 6.02 × 10²³, so the number of hydrogen atoms in a 1.62 moles of ammonia is 1.62 × 6.02 × 10²³ × 3 = 2.93 × 10² atoms.