Question

Which of the following pairs is not correctly matched?
A) allotropic form of sulphur which is more stable at room temperature – rhombic
B) the hydride of group 16 which is a liquid at room temperature – water
C) the gas formed in the upper layers of atmosphere due to UV radiations of sun – Nitrogen
D) the catalyst used in the manufacture of ${{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}$ by contact process – vanadium pentoxide

Answer 1

The ozone layer is one layer of the stratosphere, the second layer of the Earth’s atmosphere. The stratosphere is the mass of protective gases clinging to our planet.

Complete step by step solution:
A) The allotrope of sulphur that is more stable at room temperature is rhombic sulphur. Hence , this option is correctly matched
B) The hydride of group 16 which is a liquid at room temperature is water. This option is correctly matched .the other hydrides are gases at room temperature
C) The stratosphere gets its name because it is stratified, or layered: as elevation increases, the stratosphere gets warmer. The stratosphere increases in warmth with elevation because ozone gases in the upper layers absorb intense ultraviolet radiation from the sun. In this layer ozone gas is present. ozone molecules in the upper atmosphere and stratosphere absorb ultraviolet light from the Sun, providing a shield that prevents this radiation from passing to the Earth’s surface
D) The catalyst used in the manufacture of ${{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}$ by contact process – vanadium pentoxide
The catalyst used in the contact process is vanadium pentoxide. The action of the catalyst is not to yield more product but to make the reaction faster by forcing the reaction to reach equilibrium quickly.

**The correct option is C

Note:** Ozone is a molecule made up of three atoms of oxygen. It works a lot like sunscreen, blocking out harmful ultraviolet (UV) rays from the sun. In recent years, the amount of ozone in the atmosphere has decreased. So will the Earth, and all of the life on it, get sunburned? That’s the concern, and it’s one of the reasons why ozone is being looked at a lot by scientists who study climate and changes in Earth systems.