Which of the following compounds does not give nitrogen on heating?

(1) $Na{N}_3$                                                     

(2) ${\left(N{H}_4\right)}_{2}S{O}_4$

(3) $N{H}_{4}N{O}_2$                                               

(4) $\left(N{H}_4\right)2C{r}_2{O}_7$

A brown-coloured mixture of two gases is obtained by reducing 6 N nitric acid with metallic copper. This mixture on cooling condenses to a blue liquid which on freezing (-30 ^oC) gives a blue solid. The correct statement for the blue liquid or solid is: 

Which of the following statements is false?  

For $H_{3}P{O}_3$ and $H_{3}P{O}_4$, the correct choice is:

1. $H_{3}P{O}_3$  is dibasic and a reducing agent.             

2. $H_{3}P{O}_3$  is dibasic and a non-reducing agent.

3. $H_{3}P{O}_4$  is tribasic and a reducing agent.

4. $H_{3}P{O}_4$  is dibasic and a non-reducing agent.

$N{H}_{4}Cl{O}_4+HN{O}_3\left(dilute\right)\to HCl{O}_4+\left[X\right]$

$\left[X\right]\stackrel{∆}{\to }Y\left(g\right)$

$\left[X\right]$ and $\left[Y\right]$ are respectively.

(a) $N{H}_{4}N{O}_3 and N_{2}O$       (c) $N{H}_{4}N{O}_2 and N_2$

(b) $HN{O}_4 and O_2$                (d) None

One of the products of the following reaction $KCNO+{\left(NH\right)}_{4}S{O}_4$ is :

(A) $N{H}_{4}N{O}_2$                              (B) $N{H}_{4}N{O}_3$

(C) $N{H}_2-CO-N{H}_2$                  (D) $N_2$ and $N{O}_2$ both

Which of the following is correct?

(1) $S_3{O}_9$  – contains no S - S linkage.

(2) $S_2{O}_6^{2-}$   – contains – O - O linkage.

(3) ${\left(HP{O}_3\right)}_3$  – contains P – P linkage.

(4) $S_2{O}_8^{2-}$ - contains S – S linkage.

One gas bleaches the coloured matter by reduction temporary while the other one by oxidation
permanently. The gases are respectively:

(1) $S{O}_2 and C{l}_2$                             

(2) $O_3 and C{l}_2$

(3) $H_{2}S and C{O}_2$                             

(4) $C{l}_2 and S{O}_2$

$H_{2}S{O}_4$  cannot be used to prepare HI from KI as:

(1) Its reaction with KI is very slow.                   

(2) It oxidizes HI to iodine.

(3) It disproportionates HI.                               

(4) It reduces HI.

Which of the following statements is false?