wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

If at 298 K the bond energies of CH,CC,C=C and HH bonds are respectively 414,347,615 and 435 kJ mol1, the value of enthalpy change for the reaction,

H2C=CH2(g)+H2(g)H3CCH3(g) at 298 K will be:

A
125 kJ
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
+125 kJ
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
250 kJ
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
+250 kJ
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is A 125 kJ
H2C=CH2(g)+H2(g)H3CCH3(g)

According to Hess law,

ΔH=ΣEReactantsBondsBrokenΣEProductsBondsFormed

=[(C=C)+(HH)][(CC)+2(CH)]

=(615+435)[347+2(414)]

125KJ

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Thermochemistry
CHEMISTRY
Watch in App
Join BYJU'S Learning Program
CrossIcon