MyQuestionIcon

1

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Enthalpy

Heat of atomi...

Question

Heat of atomisation of $N H_{3}$ and $N_{2} H_{4}$ are $x k c a l m o l^{- 1}$ and $y k c a l m o l^{- 1}$ respectively. What will be average bond energy of $N - N$ ?

A

\frac{- 3 y - 4 x}{3} k c a l m o l^{- 1}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

B

\frac{3 y - 4 x}{3} k c a l m o l^{- 1}

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

C

\frac{3 y + 4 x}{3} k c a l m o l^{- 1}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

D

None of the above

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is B $\frac{3 y - 4 x}{3} k c a l m o l^{- 1}$
Given reactions are:
$N H_{3} \to N (g) + 3 H (g) Δ H_{a t o m} = x k c a l m o l^{- 1} = Δ H_{1} = 3 \times B E_{N - H} . . . . . .1$
$N_{2} H_{4} \to 2 N (g) + 4 H (g) Δ H_{a t o m} = y k c a l m o l^{- 1} = Δ H_{2} = 4 \times B E_{N - H} + B E_{N - N} . . . . . .2$
from equation 1 we have
$B E_{N - H} = \frac{x}{3}$
put $B E_{N - H}$ in equation 2 to get the value of $B E_{N - N}$
$Δ_{a t o m} H = y k c a l m o l^{- 1} = Δ H_{2} = 4 \times \frac{x}{3} + B E_{N - N}$
$B E_{N - N} = y - \frac{4 x}{3}$
$B E_{N - N} = \frac{3 y - 4 x}{3} k c a l m o l^{- 1}$
hence, the average bond energy of $N - N$ is $\frac{3 y - 4 x}{3} k c a l m o l^{- 1}$

Suggest Corrections

thumbs-up

3

Similar questions

Q. Heat of atomisation of

N H_{3}

N_{2} H_{4}

x k c a l m o l^{- 1}

y k c a l m o l^{- 1}

respectively. What will be average bond energy of

N - N

?

Q. Heat of atomisation of

N H_{3}

N_{2} H_{4}

x k c a l m o l^{- 1}

y k c a l m o l^{- 1}

respectively. What will be average bond energy of

N - N

?

Q. Heat of atomisation of

N H_{3}

N_{2} H_{4}

x k c a l m o l^{- 1}

y k c a l m o l^{- 1}

respectively. Average bond energy of

N - - N

Q. The standard heat of combustion of ethene gas is

- 330 K c a l m o l^{- 1}

C = C

bond energy (in kcal/mol) assuming that bond energy of

C - H

93.6 K c a l m o l^{- 1}

Δ H_{f}^{0}

C O_{2} (g)

H_{2} O (l)

- 94.2

- 61 K c a l m o l^{- 1}

respectively. Heat of atomisation of carbon and hydrogen are

150

51.5 K c a l m o l^{- 1}

Q. Heat of formation of

2

{N H}_{3} (g)

- 90 k J

; bond energies of

H - H

N - N

435 k J

390 k J

{m o l}^{- 1}

respectively. The value of the bond energy of

N \equiv N

View More

Join BYJU'S Learning Program

explore_more_icon

Explore more

Standard XI Chemistry

Join BYJU'S Learning Program

CrossIcon