Why is plaster of Paris kept in a closed container away from moisture?
Answer and explanation
Correct answer: Moisture can convert it into hard gypsum
Plaster of Paris is calcium sulphate hemihydrate, CaSO4·1/2H2O. Its governing property is that it reacts with water and changes into gypsum, CaSO4·2H2O. This hydration causes the powder to set into a hard mass, so moisture during storage can spoil its usefulness. Therefore option A is correct; the other options describe chemically impossible effects.
Frequently asked questions
What is the correct answer to this question?
Moisture can convert it into hard gypsum
Why is this the correct answer?
Plaster of Paris is calcium sulphate hemihydrate, CaSO4·1/2H2O. Its governing property is that it reacts with water and changes into gypsum, CaSO4·2H2O. This hydration causes the powder to set into a hard mass, so moisture during storage can spoil its usefulness. Therefore option A is correct; the other options describe chemically impossible effects.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
