What can happen to setting if too much water is used while making a plaster of Paris statue?
Answer and explanation
Correct answer: Setting may become weak and slow
Plaster of Paris is calcium sulfate hemihydrate, CaSO₄·½H₂O. On adding water, it rehydrates and sets into gypsum, CaSO₄·2H₂O. A correct amount of water permits this reaction and gives a workable paste. Excess water makes the mixture too dilute; after setting, the extra water leaves pores and reduces strength, while the diluted paste may set less effectively. Therefore option A is correct.
Frequently asked questions
What is the correct answer to this question?
Setting may become weak and slow
Why is this the correct answer?
Plaster of Paris is calcium sulfate hemihydrate, CaSO₄·½H₂O. On adding water, it rehydrates and sets into gypsum, CaSO₄·2H₂O. A correct amount of water permits this reaction and gives a workable paste. Excess water makes the mixture too dilute; after setting, the extra water leaves pores and reduces strength, while the diluted paste may set less effectively. Therefore option A is correct.
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.
