ASSESSMENT

A nonmetal A which is the largest constituent of air, when heated with ${\mathrm{H}}_2$ in $1:3$ ratio in the presence of a catalyst (Fe) gives a gas B. On heating with  ${\mathrm{O}}_2$ it gives an oxide C. If the oxide is passed into the water in the presence of air it gives an acid D which acts as a strong oixidsing agent. Identify A, B, C, and D.

A non-metal A which is the largest constituent of air, when heated with ${\mathrm{H}}_2$ in $1:3$ ratio in the presence of a catalyst (Fe) gives a gas B. On heating with ${\mathrm{O}}_2$ it gives an oxide C. If this oxide is passed into the water in the presence of air, it gives an acid D. which acts as a strong oxidising agent. To which group of the periodic table does this non-metal belong?

Give the steps involved in the extraction of metals of low and medium reactivity from their respective sulphide ores.

What happens when a piece of calcium is dropped in water?

What happens when sodium is kept exposed to air?

What happens when an iron nail is dipped in copper sulphate solution?

What happens when potasium is dropped in cold water?

What happens when carbon dioxide is compressed in water at high pressure?