No S-S bonds are present in?

1. \(S_{2}O_{3}^{2-}\)                                           

2. \(S_{2}O_{4}^{2-}\)

3. \(S_{2}O_{5}^{2-}\)                                                

4. \(S_{2}O_{7}^{2-}\)

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?  

The oxidation states of the S atom in $S_4{O}_6^{2-}$  from left to right, respectively, are:

1. + 6, 0, 0, and +6                         

2. +5, +1, +1, and +5

3. +5, 0, 0, and +5                           

4. +3, +1, +1, and +3

Which of the following statements is false? 

The least acidic oxide among the following is:

1. P₄O₆ 

2. P₄O₁₀ 

3. As₄O₆ 

4. As₄O₁₀ 

The correct increasing order for the acid strength of nitrogen oxides is: 

1. ${\mathrm{N}}_2\mathrm{O }< \mathrm{NO }< {\mathrm{N}}_2{\mathrm{O}}_{\mathrm{4 }}< {\mathrm{N}}_2{\mathrm{O}}_{\mathrm{3 }}< {\mathrm{N}}_2{\mathrm{O}}_5$

2. ${\mathrm{N}}_2\mathrm{O}$ $< \mathrm{NO }< {\mathrm{N}}_2{\mathrm{O}}_{\mathrm{3 }}< {\mathrm{N}}_2{\mathrm{O}}_{\mathrm{4 }}< {\mathrm{N}}_2{\mathrm{O}}_5$

3. ${\mathrm{N}}_2\mathrm{O}$ $< {\mathrm{N}}_2{\mathrm{O}}_{\mathrm{3 }}< {\mathrm{N}}_2{\mathrm{O}}_{\mathrm{4 }}< {\mathrm{N}}_2{\mathrm{O}}_{\mathrm{5 }}< \mathrm{NO}$

4. $\mathrm{NO }< {\mathrm{N}}_2\mathrm{O}$ $< {\mathrm{N}}_2{\mathrm{O}}_{\mathrm{3 }}< {\mathrm{N}}_2{\mathrm{O}}_{\mathrm{4 }}< {\mathrm{N}}_2{\mathrm{O}}_5$

Why does fluorine not produce oxyacids?

1. It is most electronegative

2. It is the most powerful oxidising agent

3. It has vacant d- orbitals

4. None of the above

The correct statement regarding H₃PO₃ is:

1. Each hydrogen atom is attached to oxygen.

2. Two hydrogen atoms are attached to oxygen atoms.

3. One atom of H is attached to oxygen.

4. None of the above.

In the nitrogen family, the H-M-H bond angle in the hybrides MH₃ gradually becomes closer to 90^o if we move from N to Sb. This shows that gradually