Question

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Q 80 An aqueous solution of magnesium
chloride solution is prepared by
dissolving 9.52 g of solid MgCl, in
1000 ml of water. Calculate the
elevation boiling point of a solution
Ky of MgCl, = 0.512 cm​

Answer 1

Given:

Mass of MgCl2, w = 9.52 gm

Volume of water, V = 1000 ml = 1000 cm³

Boiling point elevation constant, Kb = 0.512

To Find:

Elevation in boiling point, i.e., ΔTb.

Calculation:

- Molecular weight of magnesium chloride, MgCl2 = 95.2 gm

- Weight of water = 1000 cm³ × 1 gm/cm³ = 1000 gm

- Elevation in boiling point = Kb × m

⇒ ΔTb = Kb × (w × 1000)/(M.wt × W)

⇒ ΔTb = 0.512 × (9.52 × 1000)/(95.2 × 1000)

⇒ ΔTb = 0.0512 K

- So, the elevation in boiling point is 0.0512 K.