Question

Calculate The Number Of Moles
Present In: (1) 3.011 x10^23 Number
Of Oxygen Atoms. (li) 60g Of
Calcium [Given The Atomic Mass Of
Ca = 40u O=16u]​

Answer 1

Answer: (1) 0.5 moles of Oxygen (O) and 0.25 moles of O2.

(2) 1.5 moles of Calcium (Ca)

Explanation:

(1) Oxygen exist as O2 in nature.

Moles of Oxygen (O) = Given number of atoms ÷ 6.022 × 10^23

Moles of Oxygen = (3.011 × 10^23)÷(6.022 × 10^23)

Moles of oxygen = 1÷2 = 0.5

Moles of Oxygen Gas (O2) = 0.5÷2 = 0.25

(2)

Moles of Calcium (Ca) = Given weight ÷ Molecular weight

Moles of Calcium = 60 ÷ 40 = 1.5