Question

Barium sulphate is:
A. Yellow coloured
B. white coloured
C. Black coloured
D. none of these

Answer 1

The molecular formula of barium sulphate is $\text{BaS}{{\text{O}}_{4}}$. The colour of the crystals of barium sulphate is similar to the colour of the sodium chloride. The appearance of this crystalline solid is opaque.

Complete step by step answer:
- In the given question we have to identify the correct option which has the correct colour of barium sulphate.
- As we know that the main source of barium sulphate is baryte which is also white or colourless in appearance.
- The colour of sodium chloride is also white in appearance that’s why it is similar to the colour of the barium sulphate.
- Barium sulphate has no odour so it is odourless and also it is not soluble in water, alcohol and hot sulphuric acid.
- As it is an inorganic compound and crystalline solid so the structure of the solid is orthorhombic.
- The production of barium sulphate can be done by the help of barium sulphide or baryte which reacts with sulphuric acid and yields barium sulphate and hydrogen sulphide.
$\text{BaS + }{{\text{H}}_{2}}\text{S}{{\text{O}}_{4}}\text{ }\to \text{ BaS}{{\text{O}}_{4}}\text{ + HS}$

- The barium sulphate is also used as a pigment component of paint due to its white colour.
- It is also used as a filler for plastics to increase the density of the polymer.
So, the correct answer is “Option B”.

Note: In barium sulphate, the valency of barium and sulphate ion is +2 and -2 respectively. So, while forming a molecule, we combine one molecule of both barium and sulphate. Barium sulphate is harmless for humans because it is not toxic and can be used medically.