1.

The heat of combustion of CH_(4(g)),C_(("graphite")) and H_(2(g)) are 20 kcal, -40kcal and -10 kcal respectively. The heat of formation of methane is

Answer»

`-4.0` kcal
`+40` kcal
`-80` kcal
`+80` kcal

Solution :Given,
(i)`CH_(4)+2O_(2)rarrCO_(2)+2H_(2)O, DeltaH=+20 kcal`
(ii)`C+O_(2)rarrCO_(2), DeltaH=-40 kcal`
`(III) H_(2)+(1)/(2)O_(2)rarrH_(2)O, DeltaH=-10 kcal`
AIM:`C+2H_(2)rarrCH_(4)`
`(ii) +2xx"(iii)-(i) gives"`
`DeltaH=-40+2(-10)-(+20)=-80 kcal`.


Discussion

No Comment Found

Related InterviewSolutions