Which of the following is true about reactivity of group 15 elements?

1. Stability of their hydrides increases down the group.

2. Higher oxides are acidic in nature.

3. All elements form pentahalides.

4. They do not react with metals.

The element from group 15 that forms a strong bond with hydrogen is:

The condition that does not exist in the Haber process for the manufacturing of ammonia is:

1. Pressure (around 200 ×10⁵ Pa)
2. Temperature (700 K)
3. Catalyst such as iron oxide.
4. Presence of inert gases.

Number of moles of copper used when

(i) Copper reacts with dilute nitric acid

(ii) Copper reacts with concentrated nitric acid

are respectively:-

1. 1,1

2. 1,3

3. 3,1

4. 3,3

An element that does not have a d-orbital is:

The least basic compound is:

1. BiH₃

2. AsH₃

3. PH₃

4. NH₃

Incorrect statement about red phosphorus is:

1. It is hard and crystalline.

2. It is poisonous.

3. It is less reactive than white phosphorus.

4. It is insoluble in water.

Which element exhibits the highest catenation property?

1. Phosphorus

2. Nitrogen

3. Antimony

4. Bismuth

The gas released on heating H₃PO₃ is 

1. Oxygen

2. Phosphine

3. Hydrogen

4. Water vapours

PCl₅ acts as

1. Reducing agent

2. Oxidising agent

3. Dehydrating Agent

4. None of the above.