The correct order of solubility in an aqueous medium is: 

1. CuS > ZnS > Na₂S

2. ZnS > Na₂S > CuS

3. Na₂S > CuS > ZnS

4. Na₂S > ZnS > CuS

XeF₂ is isostructural with : 

1. TeF₂

2. ICI₂^-

3. SbCl₃

4. BCl₃

Which one of the following molecules contain no $\mathrm{\pi }$ -bond?

1. CO₂

2. H₂O

3. SO₂

4. NO₂

A polar molecule among the following is -

1. BF₃

2. SF₄

3. SiF₄

4. XeF₄

Considering the state of hybridisation of carbon atoms, find out the molecule among the

following which is linear.

1. HC≡CH

2. CH₂ = CH—CH₂—C = CH

3. CH₃ — CH₂ — CH₂ — CH₃

4. CH₃—CH = CH—CH₃

The correct order of increasing bond length of 

C-H, C-O, C-C and C=C is

1. C-C<C=C<C-O<C-H

2. C-O<C-H<C-C<C=C

3. C-H<C-O<C-C<C=C

4. C-H<C=C<C-O<C-C

Which of the following compounds has the lowest melting point?

1. CaBr₂

2. CaI₂

3. CaF₂

4. CaCl₂

Which of the following has the minimum bond length?

1. ^{${\mathrm{O}}_2^{-}$}

2. ${\mathrm{O}}_2^{2-}$

3. O₂

4. ^{${\mathrm{O}}_2^{+}$}

The tendency of BF₃, BCl₃, and BBr₃ to behave as Lewis acid decreases in the sequence

1. BCl₃ > BF₃ > BBr₃

2. BBr₃ > BCI₃ > BF₃

3. BBr₃ > BF₃ > BCl₃

4. BF₃ > BCl₃ > BBr₃

Given the following hydrocarbon:

The state of hybridisation of carbons marked 2, 3, 5 and 6 in the following hydrocarbon are, respectively :

1. sp, sp³, sp² and sp³

2. sp³, sp², sp² and sp

3. sp, sp², sp² and sp³

4. sp, sp² sp³ and sp²