An Aqueous Solution Of A Gas Shows Following Reactions:   (i) It Turns Red Litmus Blue (ii) When Added In Excess To A Copper Sulphate Solution A Deep Blue Colour Is Obtained. (iii) On Addition To Ferric Chloride Solution A Brownish Precipitate Soluble In HNO3 is Obtained.        Identify The Gas.

NaNO₂ gives coloured fumes on treatment with dilute acids. The colour of fumes is

When NaNO₃ is heated with (NH₄)₂SO₄ a colourless gas & a residue is obtained. The colour of residue is

The strongest reducing agent amongst the following is

Which of the following is correct order of bond strength?

Of the following acids of sulphur which one has more than one oxidation state of sulphur atom?

Of the following which compound is most unstable?

Ammonium dichromate on heating gives

White silver surface turns black when O₃ is passed over it.   

This is due to the formation of

Reaction that involves atmospheric oxygen are never promoted by

The yellow colour often shown by nitric acid may be removed by