Question

Which of the following statement is correct ?

• A. Allotropy of sulphur arises partly because of the great variety of molecular forms that can be achieved by -S-S catenation and partly because of the numerous ways in which the molecules so formed can be arranged within the crystal
• B. Both rhombic and monoclinic sulphur have $S_8$ molecules and therefore, possess same value of specific gravities
• C. Ozone on reaction with KI solution buffered with a borate buffer (pH 9.2) yields potassium iodate
• D. The ozone layer protects the earth's surface from an excessive concentration of mainly infrared (IR) radiations

Answer 1

The correct option is A Allotropy of sulphur arises partly because of the great variety of molecular forms that can be achieved by -S-S catenation and partly because of the numerous ways in which the molecules so formed can be arranged within the crystal

1) Sulphur is a non-metal which forms numerous allotropes. The allotropic forms of sulphur arises due S-S catenation. Hence due to thermal stability, allotropes of sulphur are inter-convertible.

2) Rhombic and monoclinic sulphur which has specific gravity 2.06 and 1.98 respectivily are interconvertible at 396K.

3) $2I^{-}\left(aq\right)+H_{2}O\left(\ell \right)+O_3\left(g\right)\to 2O{H}^{-}\left(aq\right)+I_2\left(s\right)+O_2\left(g\right)$

ozone do not give potassium iodate with KI.
4) Ozone layer protects the earth's surface form ultraviolet radiation.

Hence option A is correct.