Pentavalence in phosphorous is more stable when compared to that of nitrogen even through they belong to same group is due to

• reactivity of phosphorous

• inert nature of nitrogen

• dissimilar electronic configuration

• larger size of phosphorous atom

Ferric sulphate on heating gives

• SO₂ and SO₃

• SO₂ only

• SO₃ only

• S

When AgNO₃ is heated to red hot, what is formed?

• Ag

• Ag₂O₃

• Ag₂O

• AgO₂

424.

Match List-I with List-II and select the correct answer using the codes given below

List I (Oxyacid of sulphur)	List II (Oxidation state of sulphur)
A. H2SO3	1. +1
B. H2S2O6	2. +6
C. H2S2O2	3. +4
D. H2S2O8	4. +5

Codes

• A  B  C  D

  4  3  1   2

• A  B  C  D

  2  1   3  4

• A  B  C  D

  4  3   2  1

• A   B  C  D

  3  4   1   2

Consider the following statements.

1.The aqueous solution of FeCl₃ is acidic in nature.

2. Anhyd. FeCl₃ can be obtained by heating hydrated ferric chloride.

3. A solution of ferric chloride on standing gives a brown precipitate.

The correct statement (s) is/are

• 1 and 2

• 2 and 3

• 1 and 3

• All of these

Mercurous ion (Hg${}_2^{2+}$) gives white precipitate on reacting with

• Kl solution

• H₂S gas

• K₂Cr₂O₇ solution

• HCl solution

In case of ring rest of NO${}_3^{-}$ ion, the complex formed has formula [Fe (H₂O)₅ NO]SO₄. The oxidation state of iron in the complex is

• +1

• +2

• +3

• +6

Which one of the following is not an amphoteric substance?

• HNO₃

• HCO${}_3^{-}$

• H₂O

• NH₃

The structure of orthophosphoric acid is

In the manufacture of ammonia by Haber's process, N₂ (g) + 3H₂ $\rightleftharpoons$2NH₃(g) + 92.3 KJ which of the following conditions is unfavourable ?

• Increasing the temperature

• Increasing the pressure

• Reducing the temperature

• Removing ammonia as it is formed