Question

5) Find the molecular mass of the following. Compounds.
MgCl2, NaOH, NaHCO,​

Answer 1

Answer:-

We have to find the molecular masses of :

• MgCl₂ (Magnesium chloride)

• NaOH (Sodium hydroxide)

• NaHCO₃ (Sodium Bicarbonate)

Molecular mass is defined as the sum of the atomic masses of all the atoms of the elements in a given compound.

1) MgCl₂

• Atomic weight of 1 atom of Mg = 24 a.m.u

• Atomic weight of 1 atom of Cl = 35.5 a.m.u

So,

Molecular mass of MgCl₂ is:

⟶ (1) 24 + 2(35.5)

⟶ 24 + 71

⟶ 95 a.m.u

2) NaOH

• Atomic weight of 1 atom of Na = 23 a.m.u

• Atomic weight of 1 atom of O = 16 a.m.u

• Atomic weight of 1 atom of H = 1 a.m.u

So,

Molecular mass of NaOH is :

⟶ (1) 23 + (1) 16 + (1) 1

⟶ 23 + 16 + 1

⟶ 40 a.m.u

3) NaHCO₃

• Atomic weight of 1 atom of Na = 23 a.m.u

• Atomic weight of 1 atom of H = 1 a.m.u

• Atomic weight of 1 atom of C = 12 a.m.u

• Atomic weight of 1 atom of O = 16 a.m.u

So,

Molecular mass of NaHCO₃ is :

⟶ (1) 23 + (1) 1 + 1 (12) + 3(16)

⟶ 23 + 1 + 12 + 48

⟶ 84 a.m.u