Question

Calculate the molar mass of the following compounds. 

1. urea [CO(NH₂)₂] 

2. acetone [CH₃COCH₃] 

3. boric acid [H₃BO₃] 

4. sulphuric acid [H₂SO₄ ]

Answer 1

1. urea [CO(NH₂)₂] 

Atomic mass of C =12 

Atomic mass of O =16 

Atomic mass of 2(N) = 28 

Atomic mass of 4(H) = 4 

∴ Molar mass of Urea = 60

2. acetone [CH₃COCH₃] 

Atomic mass of 3(C) = 36 

Atomic mass of 1(0) = 16 

Atomic mass of 6(H) = 6 

∴ Molar mass of Acetone = 58

3. boric acid [H₃BO₃] 

Atomic mass of B = 10 

Atomic mass of 3(H) = 3 

Atomic mass of 3(O) = 48 

∴ Molar mass of Boric acid = 61

4. sulphuric acid [H₃SO₄ ]

Atomic mass of 2(H) = 2 

Atomic mass of 1(S) = 32 

Atomic mass of 4(O) = 64 

∴ Molar mass of Sulphuric acid = 98