The colour of an iodine solution is discharged by shaking it with an aqueous solution of:

The gaseous product of the reaction between $Sn$ and conc. $H_2SO_4$ is

Which of the following compounds does not produce a green-coloured product on thermal decomposition?

Identify the substance oxidised,reduced,oxidising agent,and reducing agent for each of the following reactions:
$(a)$ $2AgBr_{(s)} + C_6H_6O_{2(aq)} \to 2Ag_{(s)} + 2HBr_{(aq)} + C_6H_4O_{2(aq)}$
$(b)$ $HCHO_{(l)} + 2[Ag(NH_3)_2]^+_{(aq)} + 3OH^-_{(aq)} \to 2Ag_{(s)} + HCOO^-_{(aq)} + 2NH_{3(aq)} + 2H_2O_{(l)}$
$(c)$ $HCHO_{(l)} + 2Cu^{2+}_{(aq)} + 5OH^-_{(aq)} \to Cu_2O_{(s)} + HCOO^-_{(aq)} + 3H_2O_{(l)}$
$(d)$ $N_2H_{4(l)} + 2H_2O_{2(l)} \to N_{2(g)} + 4H_2O_{(l)}$
$(e)$ $Pb_{(s)} + PbO_{2(s)} + 2H_2SO_{4(aq)} \to 2PbSO_{4(s)} + 2H_2O_{(l)}$

$A$ solution of $KMnO_{4}$ on reduction yields either a colourless solution,a brown precipitate,or a green solution depending on the $pH$ of the solution. What different stages of the reduction do these represent and how are they carried out?

Which of the following can react with $K_{2}Cr_{2}O_{7}$?