Question

(a) Give the names of the elements present in the following compounds.

(i) Quick time

(ii) Hydrogen peroxide

(iii) Baking powder.

(iv) PotassiumSulphate.

Answer 1

1) Quicklime is the common name for Calcium Oxide (CaO). Therefore, it consists of the elements Calcium and Oxygen.

2) Hydrogen Peroxide is $H_{2} O_{2}$. Hence, it consists of Hydrogen and Oxygen.

3) I guess this one must be 'Baking Soda'. Its chemical composition is $NaHCO_{3}$ (sodium hydrogen carbonate). Hence, it consists of the elements Sodium, Hydrogen, Carbon and Oxygen.
(Baking powder consists of a carbonate/bicarbonate and a weak acid).

4) Potassium Sulphate is chemically $K_{2} SO_{4}$. Hence, it consists of the elements Potassium, Sulphur and Oxygen.

Answer 2

second one containsconsists of Hydrogen and Oxygen.