Question

Hydrated calcium CaSo4.2H20
what is the name given to water molecules present in Salt
calculate the percentage of water molecules

Answer 1

Answer:

The compound shown in the figure is calcium sulphate dyhydrite.

The common name of above compound is Gypsum.

The Chemical is CaSO4. 2H2O.

Usually, gypsum has water associated in the molecular structure (CaSO4·2H2O) and is approximately 23.3 percent Ca and 18.5 percent S (plaster of paris).

Explanation:

Answer 2

The percentage of water (%) crystallization is 18.36 percent (%)

Explanation:

• The name given to water molecules present in salt is Water of crystallization or hydrated water.
• These molecules of water are present inside the crystals and are not bonded directly to the metal cation, present in the complex salt.

Calculation of the percentage of water molecules

The formula of copper sulfate =$CuSO_4.2H_2O$

Relative atomic masses = Cu= 64, S = 32, O = 16 and H = 1

Relative formula mass of crystals = 64 + 32 + (4 x 16) + {2x (1 + 1 + 16)} = 196

Relative mass of seven water molecules = 2 x 18 = 36

∴ Percentage of water(%) = $36\times \dfrac{100}{196}$ = 18.36 %

The percentage of water (%) of crystallization in the crystals is 18.36 percent (%).