The bond dissociation energies of X2,Y2 and XY are in the ratio of 1:0.5:1.Δ H for the formation of XY is -100 kJ mol- 1. . The bond dissociation energy of X2 will be kJ mol- 1.

Question

The bond dissociation energies of X2,Y2 and XY are in the ratio of 1:0.5:1.Δ H for the formation of XY is -100 kJ mol- 1. . The bond dissociation energy of X2 will be kJ mol- 1. (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

The ratio of bond dissociation energies of

X_{2}, Y_{2}

and

X Y

is

1 : 0.5 : 1

∴

Bond dissociation energies of

X_{2}, Y_{2}

and

X Y

are:

Δ H (X - X) = x

Δ H (Y - Y) = 0.5 x

Δ H (X - Y) = x

The chemical equation for formation of

X Y

is :

\frac{1}{2} X_{2} + \frac{1}{2} Y_{2} \to X Y

Δ H = \sum m Δ H (reactant bonds)

- Σ n Δ H (product bonds)

∴ - 100 = [\frac{1}{2} Δ H (X - X) + \frac{1}{2} Δ H (Y - Y)] - Δ H (X - Y)

- 100 = [\frac{1}{2} x + \frac{1}{2} \times 0.5 x] - x

- 100 = [\frac{x}{2} + \frac{x}{4}] - x

- 100 = \frac{6 x}{8} - x

- 100 = \frac{6 x - 8 x}{8}

- 100 = \frac{- 2 x}{8}

∴ x = \frac{100 \times 8}{2} = 400

∴

Bond dissociation energy of

X_{2} = 400 k J m o l^{- 1} .

Q. The bond dissociation energies of X2​,Y2​ and XY are in the ratio of 1:0.5:1.ΔH for the formation of XY is −100kJmol−1. . The bond dissociation energy of X2​ will be_____ kJmol−1.

Q. The bond dissociation energies of $X_{2}, Y_{2}$ and $X Y$ are in the ratio of $1 : 0.5 : 1.Δ H$ for the formation of $X Y$ is $- 100 k J m o l^{- 1} .$ . The bond dissociation energy of $X_{2}$ will be_____ $k J m o l^{- 1} .$