Question

How much heat ( in kcal ) will be required at constant pressure to form 1.28 kg of `CaC_(2)` from CaO(s) & C(s) ?
Given: `Delta_(f)H^(@)(CaO,s)=-152 kcal/mol. `
`DeltaH_(f)(CaC_(2),s)=-14 kcal/mol`
`DeltaH_(f)(CO,g)=-26 kcal/mol`

Answer 1

[2240]
`CaO(s)+3C(s) to CaC_(2)(s)+CO_(g)`
`Delta_(f)H^(@)=(-14-26)-(-152)=+112 kcal//mol`
Total heat required `=((1280)/(64))xx112implies 2240 kcal`