`H_(2)S` acts only as reducing agent while `SO_(2)` can act both as a reducing agent and as an oxidising agent. How will you account for it ?

Explain why HNO_(3) acts only as oxidising agent while HNO_(2) can act both as a reducing agent and an oxiding agent?

Explain the following : (a) An acidified K_2 Cr_2 O_7 paper turns green when exposed to SO_2 . (b) H_2 S acts only as reducing agent while SO_2 can act both as a reducing agent and an oxidising agent. (c) SO_2 acts as a bleaching agent. (d) Sugar turns black on addition of conc. H_2 SO_4 . (e) Ozone destroys mercury meniscus. (f) SF_6 is known, but SH_6 is not known.

Which acts as reducing agent as well as oxidising agent ?

H_2O_2 is acting as a reducing agent as well as oxidising agent

H_2S acts only as reducing agent while SO_2 acts as an oxidising as well as reducing agent. Why?

Give reasons for the following: (1) HNO_3 acts only as an oxidising agent while HNO_2 can act both as a reducing agent and an oxidising agent (2) Chlorine liberates iodine from Kl solution.