Question

Calculate the percentage of water of crystallisation in the sample of potash alum, k2so4.al2(so4)3.24h2o

Answer 1

Given:

The sample of potash alum K2SO4.Al2(SO4)3.24H2O.

To Find:

The percentage of water of crystallization in the given sample of potash alum.

Calculation:

- From the formula, the mass of potash alum, i.e., K2SO4.Al2(SO4)3.24H2O = (39 × 2) + 32 + (16 × 4) + (27 × 2) + (96 × 3) + (18 × 24)

⇒ W = 78 + 32 + 64 + 54 + 288 + 432

⇒ W = 948 gm

- The mass of water of crystallization in potash alum = (18 × 24)

w = 432 gm

- Percentage of water of crystallization = (w/W) × 100

⇒ % of water of crystallization = (432/948) × 100

⇒ % of water of crystallization = 45.57 %

- So, the percentage of water of crystallization in the sample of potash alum is 45.57 %.