pBlock ElementsII 1 Question 3
3. The oxoacid of sulphur that does not contain bond between sulphur atoms is
(2019 Main 10 April I)
(a) $\mathrm{H} _{2} \mathrm{S} _{2} \mathrm{O} _{3}$
(b) $\mathrm{H} _{2} \mathrm{S} _{2} \mathrm{O} _{4}$
(c) $\mathrm{H} _{2} \mathrm{S} _{2} \mathrm{O} _{7}$
(d) $\mathrm{H} _{2} \mathrm{S} _{4} \mathrm{O} _{6}$
Show Answer
Answer:
Correct Answer: 3. (c)
Solution:
- $\mathrm{S}-\mathrm{S}$ bond is not present in $\mathrm{H} _{2} \mathrm{S} _{2} \mathrm{O} _{7}$ (pyrosulphuric acid or oleum).
While the other given oxoacids of sulphur, i.e. $\mathrm{H} _{2} \mathrm{S} _{2} \mathrm{O} _{3}$ (thiosulphuric acid), $\mathrm{H} _{2} \mathrm{S} _{2} \mathrm{O} _{4}$ (hyposulphurous or dithionous acid) and $\mathrm{H} _{2} \mathrm{S} _{4} \mathrm{O} _{6}$ (tetrathionic acid) contains $\mathrm{S}-\mathrm{S}$ bonds.