A potassium salt (F) gives a brown coloured gas with dil.HCl in presence of air and forms a dark brown colored ring (G) with ferrous sulfate and acetic acid at the junction of liquids. The salt (F) decolourises the acidified $KMn{O}_4$  solution. Choose the correct option(s) for the (F) and (G):

Addition of potassium iodide solution to the salt solution(F) followed by freshly prepared starch solution and acidification with acetic acid produces blue colour.

(G) is paramagnetic complex ${\left[\mathrm{Fe}{\left({\mathrm{H}}_2\mathrm{O}\right)}_5\left({\mathrm{NO}}_2\right)\right]}^{2+}$

addition of acidified $Co{\left(N{O}_3\right)}_2$ to the salt solution (F) produces a yellow coloured low spin complex.

Anion of F can be removed using thiourea and $N{H}_{2}S{O}_{3}H$ in acidic medium during detection of $N{O_3}^{-}$ ion using Brown ring test.