(a). What is gypsum? What happens when gypsum is heated to `100^(@)C` (373K)?
(b) Name a sodium compound which is used for making borax and glass.
(c) Name the compound which is used in hospitals for setting fractured bones.
(d) Which is the real bleaching agent present in bleaching powder?

Name the compound of sodium which is used to make borax and glass.

What are antacids ? Name two compounds which are used as antacids ?

(a) What is a solar cell ? Draw the labelled diagram of a solar cell. (b) Name the semi-conductor material which is usually used for making solar cells. (c ) Write the uses of solar cells.

(a) Name a sodium compound used for softening hard water. (b) Which compound of calcium is used for disinfecting drinking water supply? (c) Name a metal compound which has detergent properties (cleansing properties). (d) Name one compound of calcium which is used for removing the colour of a coloured cloth. (e) State a peculiar (or remarkable) property of plaster of paris. (f) Name the substance obtained by the action of chlorine on solid (dry) slaked lime.

Identify the compound of calcium which is used for plastering of fractured bones. With the help of chemical equation show how is it prepared and what special precautions should be taken during the preparation of this compound.

(a) Name the chemical compound which is electrolysed in molten state to obtain aluminium metal. Which gas is evolved during this process? (b). Name the chemical compound which is electrolysed in molten state to obtain sodium metal. Which gas is produced in this process? (c) name the gas produced when calamine ore is calcined (d) Name the gas evolved when cinnabar ore is roasted.

A neutral compound (A) C_3H_6O_2 is formed by the reaction of an acid (B) which is present in ant's sting and an alcohol (C) which is used in the preparation of tincture of iodine. Identify the compounds B and C?