A mixture of two white substances is soluble in water. This solution gives brown colour gas on passing chlorine gas. Another sample of solution gives white precipitate with ${\mathrm{BaCl}}_2$ which is insoluble in concentrated $\mathrm{HCl}$. The original solution of the mixture gives white precipitate with large excess of $\mathrm{NaOH}$ solution whose suspension is used as an antacid. After filtering off this precipitate, the filtrate was boiled with excess $\mathrm{NaOH}$. Solution gave a yellowish precipitate on adding ${\mathrm{NaClO}}_4$. One of the compound of the mixture forms alum. Identify the mixture.

A unknown inorganic compound $\left(\mathrm{X}\right)$ gave the following reaction:

(i) on heating $\text{'}\mathrm{X}\text{'}$ gave a residue, oxygen and oxide of nitrogen.

(ii) Addition of acetic acid and ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ to its aqueous solution give a yellow precipitate.

(iii) Addition of $\mathrm{NaOH}$ to its aqueous solution first forms a white precipitate. Dissolve in the excess of the reagent.

An unknown inorganic compound $\left(\mathrm{X}\right)$ loses its water of crystallisation. On heating its aqueous solution gives the following reaction:

(i) It gives a white turbidity with dilute $\mathrm{HCl}$ solution.

(ii) It decolourises a solution of iodine in $\mathrm{KI}$.

(iii) It gives a white precipitate with ${\mathrm{AgNO}}_3$ solution which turns black on standing.

Identify compound $\left(\mathrm{X}\right)$ and give chemical equations for the reactions at step (i), (ii) & (iii).

An inorganic compound $\left(\mathrm{X}\right)$ gives brick red flame on performing the flame test. This also give the following tests:

(i) Smell of chlorine when placed in moist air.

(ii) If $\mathrm{KI}$ & ${\mathrm{CH}}_3\mathrm{COOH}$ are added to its suspension in water, a brown colour is obtained. Identify $\left(\mathrm{X}\right)$ and write down equations for reactions at step (i) and (ii).

Two solid laboratory reagents $\left(\mathrm{A}\right)$ and $\left(\mathrm{B}\right)$ give following reactions:

Compound: $\left(\mathrm{A}\right)$

(i) On strongly heating it gives two oxides of sulphur.

(ii) On adding aqueous $\mathrm{NaOH}$ solution to its aqueous solution, a dirty green precipitate is obtained which starts turning brown on exposure to air.

Compound: $\left(\mathrm{B}\right)$

(iii) It imparts green colour to flame.

(iv) Its solution doesn't give precipitate on passing ${\mathrm{H}}_2\mathrm{S}$

(v) When it is heated with ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ & conc. ${\mathrm{H}}_2{\mathrm{SO}}_4$, a red gas is evolved. The gas when passed in aqueous $\mathrm{NaOH}$ solution turns it yellow.

Identify $\left(\mathrm{A}\right)$ to $\left(\mathrm{B}\right)$ and give chemical reactions.

An aqueous solution of an unknown compound $\left(\mathrm{X}\right)$ gives the following reactions.

(i) It gives brown precipitate with alkaline ${\mathrm{KMnO}}_4$ solution

(ii) It forms $\mathrm{HCl}$ & evolved ${\mathrm{O}}_2$ when reacts with ${\mathrm{Cl}}_2$ gas.

(iii) It liberates ${\mathrm{I}}_2$ from an acidified $\mathrm{KI}$ solution.

(iv) It gives orange yellow colour with acidified titanic sulphate solution.

Identify $\left(\mathrm{X}\right)$ and give the chemical equations for the reactions (i), (ii) & (iii).