One gram mole of graphite and diamond were burnt to form CO2 gas.Cgraphite+O2(g)⟶CO2(g);ΔHo=−399.5kJCdiamond+O2(g)⟶CO2(g);ΔHo=−395.4kJ
Assertion- C(graphite)+O2(g)→CO2(g),
ΔH=−393.5k.J
C(diamond)+O2(g)→CO2(g),
ΔH=−395.4k.J
Reason(R): graphite is more stable than diamond, so heat of combustion is less.
Cgraphite + O2(g) → CO2(g)
ΔH = −94.05kcal mol−1
Cdiamond + O2(g) → CO2(g); ΔH = −94.50 kcal mol−1 therefore