The entropy change in the fusion of one mole of a solid melting at 27ºC (Latent heat of fusion, 2930 J mol^-1) is :

9.77 J K^-1 mol^-1
10.73 J K^-1 mol^-1
2930 J K^-1 mol^-1
108.5 J K^-1 mol^-1

Solution

a
b
c
d

Solution

Which one of the following pairs of species have the same bond order?

CN^- and NO⁺
CN^- and CN⁺
\(O_{2}^{-}\) and CN^-
NO⁺ and CN⁺

Solution

Arrange the following ions in the order of decreasing X – O bond length, where X is the central atom in

\(CIO_{4}^{-}\), \(SO_{4}^{2-}\),\(PO_{4}^{3-}\),\(SiO_{4}^{-}\)
\(SiO_{4}^{4-}\), \(PO_{4}^{3-}\),\(SO_{4}^{2-}\),\(CIO_{4}^{-}\)
\(SiO_{4}^{4-}\), \(PO_{4}^{3-}\),\(CIO_{4}^{-}\),\(SO_{4}^{2-}\)
\(SiO_{4}^{4-}\), \(SO_{4}^{2-}\),\(PO_{4}^{3-}\),\(CIO_{4}^{-}\)

Solution

More will be the electronegativity of X lesser will be the bond length of X-O bond.

In pyrophosphoric acid, H₂P₂O₇, number of ? and d? – p? bonds are respectively

8 and 2
6 and 2
12 and zero
12 and 2

Solution

a
b
c
d

The calculated bond order in \(O_{2}^{-}\) ion is

1
1.5
2
2.5

Solution

How many ? and ? bonds are present in toluene?

3? + 8?
3? + 10?
3? + 15?
6? + 3?

Solution

Which of the following has p? – d? bonding ?

\(NO_{3}^{-}\)
\(SO_{3}^{2-}\)
\(BO_{3}^{3-}\)
\(CO_{3}^{2-}\)

Solution

a
b
c
d

Solution

Only d of Sand p of O can be involved in ? bonding.

The bond order in N₂⁺ is

1.5
3.0
2.5
2.0

Solution

Which of the following statements is not correct for sigma and pi-bonds formed between two carbon atoms?

Sigma-bond determines the direction between carbon atoms but a pi-bond has no primary effect in this regard
Sigma-bond is stronger than a pi-bond
Bond energies of sigma- and pi-bonds are of the order of 264 kJ/mol and 347 kJ/mol, respectively
Free rotation of atoms about a sigma-bond is allowed but not in case of a pi-bond

Solution

As sigma bond is stronger than the ? (pi) bond, so it must be having higher bond energy than ?(pi) bond.

In which of the following species is the underlined carbon having sp³– hybridisation ?

CH₃– COOH
CH₃ CH₂ OH
CH₃COCH₃
CH₂ = CH - CH₃

Solution

In CH₃CH₂OH underlined C is forming 4 ? bonds, hence sp^{3/sup> hybridisation. In others it is sp² hybridised (due to 3 ? bonds).}

Attempted

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