Chemistry Questions

Plaster of Paris ______.

I. changes into gypsum on mixing with water

II. is CaSO4.2H2O

III. is used for decoration

Fill in the blank with the most appropriate option.

Ethanol is denatured to ___.

Which of the following statements is/are true or false?

Statements :

A) H2S burns in air to give H2O and SO2

B) The decomposition of Ferrous Sulphate into Fe2O3, SO2 and SO3 occurs in the presence of heat.

The most abundant of the rare gases i ?

Washing soda is used ______.

I. for removing permanent hardness of water

II. for disinfecting drinking water

III. as a cleaning agent for domestic purpose

Which of the following statements are CORRECT?

I. Esters are sweet smelling substance.
II Esters are used in making perfumes.
III. Functional group of ester is R-O-RꞋ.

Out of all known elements, the minimum number is of ______.

Which  of  the  following  substances  cause temporary hardness in water?

1. Mg(HCO3)2

2. Ca(HCO3)2

3. CaCl2

4. MgSO4