Question

The minimum heat energy required to cause
complete dissociation of n moles of H2, gas at
constant temperature T is
ar
(1) nRT
(2) =nRT
2
(3) of
ol
nRT
(4)
nRT
2​

Answer 1

We know that, the bond dissociation energy of hydrogen gas is enormous, i.e. 436$kJ/mol$.

∴ The energy required for N moles of $H_2$ = N × 436 kJ = 436 N kJ.

However, if the condition required for the reaction is constant temperature, then this not possible. In order to calculate the minimum heat energy to cause the complete dissociation of N moles in $H_2$, the following criteria is deemed necessary;

$W = nRT$ L$n$ $(\frac{V_2}{V_1} )$

in which,

$W$ = Energy /work done

$n$ = no. Of moles

$T$ = temperature

$V_1$ = initial volume

$V_2$ = final volume

Since the options have not been provided in a proper manner, I ope this helps.

Answer 2

Answer:

1/2 nRT

Explanation:

Question wants heat energy expelled after DISSOCIATION so in the process what's actually happening is

H2------>H

so for n moles of H2 2n moles H are formed, and so using formula U(internal energy) = nfRT/2

we get

(2n.3RT)/2 - (n.5RT)/2 (Final -Initial)

which gives us 0.5RT