Home
Class 11
CHEMISTRY
delta(f) U^(Ө) "of formation of" CH(4)(g...

`delta_(f) U^(Ө) "of formation of" CH_(4)(g)` at a certain temperature is `-393Jmol^(-1).` The value of `delta H^(Ө)is:`

A

zero

B

`ltDelta_(f)U^(o.)`

C

`gtDelta_(f)U^(o.)`

D

equal to `Delta_(f)U^(o.)`

Text Solution

Verified by Experts

The correct Answer is:
B
`C_((S))+2H_(2(g))rarrCH_(4)(g)`
`Delta_(f)H=Delta_(f)U+Deltan_((g))RT=Delta_(f)U+{4-((15)/(2))}xxRT`
`=Delta_(f)U-(7)/(2)RT" "therefore Delta_(f)HltDelta_(f)U`
Promotional Banner

Similar Questions

Explore conceptually related problems

DeltaU^(@) of combustion of CH_(4(g)) at certain temperature is -"393 kJ mol"^(-1) . The value of DeltaH^(@) is

The value of Delta _(f) f^(Ө) for formation of Cr_(2) O_(3) is – 540 kJmol−1and that of Al_(2) O_(3) is – 827 kJmol^(−1) . Is the reduction of Cr_(2) O_(3) possible with Al ?

The standard enthalpy of formation (Delta_(f)H^(@)) at 298K for methane (CH_(4(g))) is -74.8kJ mol^(-1) . The additional information required to determine the average energy for C-H bond formation would be :