Question

Give reasons for the following.
i.Oxygen is a gas but sulphur is solid.
ii.${O_3}$acts as a powerful oxidising agent.
iii.$Bi{H_3}$is the strongest reducing agent amongst all the hydrides of group 15 elements.

Answer 1

Hint : We must know the role of oxidising agent and reducing agent. Also we must know the character of oxygen and ozone. Ozone is an allotropic form of oxygen and it is a powerful oxidizing agent. We have to consider each case one by one

Complete step by step solution :
In oxygen molecule, the intermolecular forces are weaker van der Waals forces which makes it existence as gas, whereas in sulphur, strong $S = S$bond isn't formed so its exist in puckered structure and held together by attraction and exists as a polymeric molecule.
${O_3}$(Ozone) acts as a sturdy oxidant because it produces oxygen which is nascent, meaning the oxygen that has been made in an exceedingly chemical change. There’s a belief that it's a monatomic oxygen radical, which is way more reactive. Nascent oxygen is believed to be very reactive and can react with differing kinds of biomolecules. It's considered to be very toxic for the aerobic life forms because oxygen is converted into nascent oxygen.
On moving from the best to bottom in hydrides of group 15, bond length increases, atomic size increases with decrease within the steadiness of the hydrides. The likelihood of hydrogen removal also increases so the number also increases and $Bi{H_3}$ is the strongest reductant amongst all the hydrides of group 15. Because the steadiness of group 15 elements decreases, from $N{H_3}$to $Bi{H_3}$ the reducing character of hydrides from $N{H_3}$ to $Bi{H_3}$ increases.

Note : We must know that oxygen molecules have weaker van der waal’s force and ${O_3}$forms nascent oxygen which produce toxicity in the water bodies and destroy aquatic flora making it unsuitable for living and $Bi{H_3}$ removes hydrogen which makes it strongest reductant among group 15.