A compound "X", upon reaction with H₂O, produces a colourless gas "Y" with a rotten fish smell.  Gas 'Y' is absorbed in a solution of CuSO₄ to give Cu₃P₂ as one of the products. The compound 'X' will be:

1. Ca₃P₂

2. ${\mathrm{NH}}_4\mathrm{Cl}$

3. ${\mathrm{As}}_2{\mathrm{O}}_3$

4. Ca₃(PO₄)₂

Which of the following oxoacids of phosphorus shows the strongest reducing property?
1. H₄P₂O₇
2. H₃PO₃
3. H₃PO₂
4. H₃PO₄

Which element from $p\mathrm{\pi }-\mathrm{p\pi }$ multiple bonds with itself and with carbon and oxygen?

1.  P, As

2.  N, As

3.  N, P

4.  N

Which hydride has the lowest boiling point?

1. ${\mathrm{H}}_2\mathrm{O}$

2. ${\mathrm{H}}_2\mathrm{S}$

3. ${\mathrm{H}}_2\mathrm{Se}$

4. ${\text{H}}_2\mathrm{Te}$

${\mathrm{SO}}_2+{\mathrm{H}}_2\mathrm{S}\to \mathrm{product}$. The final product will be:

1. ${\mathrm{H}}_2\mathrm{O}+\mathrm{S}$

2. ${\mathrm{H}}_2{\mathrm{SO}}_4$

3. ${\mathrm{H}}_2{\mathrm{SO}}_3$

4. ${\mathrm{H}}_2{\mathrm{S}}_2{\mathrm{O}}_3$

On passing $H_{2}S$ through the acidified $FeC{l}_3$ solution, $FeC{l}_3$ is converted into:

(1) $FeC{l}_2$

(2) $F{e}_2{(SO}_{}$₄)3

(3) FeS

(4) $FeS{O}_4$

Which does not give ammonia with water?

1. $M{g}_3{N}_2$

2. AlN

3. $CaC{N}_2$

4. $Ca{\left(CN\right)}_2$

Which of the following Group 15 hydrides has the greatest tendency to form coordination complexes?

Non-combustible hydride is:

(1) $P{H}_3$

(2) $As{H}_3$

(3) $Sb{H}_3$

(4) $N{H}_3$