Non-metals form two types of oxides. Choose these two types from the following oxides:
$SO_2, NO_2, CO, H_2O, N_2O$

Describe ionic compounds on the basis of the following properties:
$(i)$ Strong force of attraction between positive and negative ions:
$(ii)$ Solubility of compounds in water.
$(iii)$ Electrical conductivity.

Which of the following metals is obtained in free state in nature?

What happens when copper oxide is heated in the presence of dihydrogen gas?

Write the balanced chemical equation for each of the following cases:
$(a)$ Magnesium is treated with very dilute $HNO_3$.
$(b)$ Aluminium powder is added to $Fe_2O_3$.
$(c)$ Zinc sulphide is roasted.

What is the percentage of $H_{2}SO_{4}$ in concentrated $H_{2}SO_{4}$ (in $\%$)?