What will be the enthalpy of formation of toluene considering the data given? Bond energies of C — C = 79 kcal, C = C = 135 kcal, C — H = 102 kcal , heat of atomisation of C = 156.8 kcal and heat of atomisation of H = 49.5 kcal

Question

What will be the enthalpy of formation of toluene considering the data given? Bond energies of C — C = 79 kcal, C = C = 135 kcal, C — H = 102 kcal , heat of atomisation of C = 156.8 kcal and heat of atomisation of H = 49.5 kcal  (A)  -43.4 kcal  (B)  43.4 kcal  (C)  114.6 kcal  (D)  -114.6 kcal

Tardigrade Admin · Accepted Answer

7C(g)+4H2(g) arrow underset textTolueneC7H8(g) Δ H = Enthalpy of atomisation-Bond enthalpies =(7× 156.8+8× 49.5)-(8× 102+4× 79+3× 135) =1493.6-1537 =-43.4 kcal

Q. What will be the enthalpy of formation of toluene considering the data given? Bond energies of $C — C = 79 k c a l, C = C = 135 k c a l, C — H = 102 k c a l$ , heat of atomisation of $C = 156.8 k c a l$ and heat of atomisation of $H = 49.5 k c a l$

$- 43.4 k c a l$

$43.4 k c a l$

$114.6 k c a l$

$- 114.6 k c a l$

$7 C_{(g)} + 4 H_{2 (g)} \to Toluene C_{7} H_{8 (g)}$
$Δ H$ = Enthalpy of atomisation-Bond enthalpies
$= (7 \times 156.8 + 8 \times 49.5) - (8 \times 102 + 4 \times 79 + 3 \times 135)$
$= 1493.6 - 1537$
$= - 43.4$ kcal

Q. What will be the enthalpy of formation of toluene considering the data given? Bond energies of C—C=79kcal,C=C=135kcal,C—H=102kcal , heat of atomisation of C=156.8kcal and heat of atomisation of H=49.5kcal

−43.4kcal

43.4kcal

114.6kcal

−114.6kcal