Question

Calculate the `DeltaH` in joules for
`C("graphite")toC("diamond")`
from the following data:
`C("graphite")+O_(2)(g)toCO_(2)(g):" "DeltaH^(@)=-393.5kJ`
`C("diamond")+O_(2)(g)toCO_(2)(g)," "DeltaH^(@)=-395.4kJ`
A. 1900
B. `-788.9xx10^(3)`
C. `190000`
D. `+788.9xx10^(3)`

Answer 1

Correct Answer - A
`C("graphite")+O_(2)(g)toCO_(2)(g),DeltaH^(@)=-393.5kJ`
`underline(CO_(2)(g)toC("diamond")+O_(2)(g)," "DeltaH^(@)=+395.4kJ)`
On adding, `underline(C"graphite")toC("diamond"),DeltaH^(@)=+1900J=+1.9kJ)`