The heat of formations for CO2(g), H2O (l) and CH4(g) are -400 kJ mol-1 , -280 KJ mol-1 and -70 KJ mol-1 respectively. The heat of combustion of CH4 in kJ mol-1 is

Question

The heat of formations for CO2(g), H2O (l) and CH4(g) are -400 kJ mol-1 , -280 KJ mol-1 and -70 KJ mol-1 respectively. The heat of combustion of CH4 in kJ mol-1 is (A)  890  (B)  -160  (C)  -890  (D)  -90

Tardigrade Admin · Accepted Answer

Δ Hreaction =∑Δ Hf product -∑Δ Hf reactant Δ Hf of a single element like O2, H2, Cl2 is considered equal to zero CH4+2O2 → CO2+2H2O Δ HReaction =Δ Hf (CO2)+2Δ Hf ⋅ (H2O) -Δ Hf (CH4)-2Δ Hf (O)2 =-400+2(-280)-(-70)-0 =-890 KJ mol-1

Q. The heat of formations for $C O_{2} (g), H_{2} O (l)$ and $C H_{4} (g)$ are $- 400 k J m o l^{- 1}$ , $- 280 K J m o l^{- 1}$ and $- 70 K J m o l^{- 1}$ respectively. The heat of combustion of $C H_{4}$ in $k J m o l^{- 1}$ is

$890$

$- 160$

$- 890$

$- 90$

Q. The heat of formations for CO2​(g),H2​O(l) and CH4​(g) are −400kJmol−1 , −280KJmol−1 and −70KJmol−1 respectively. The heat of combustion of CH4​ in kJmol−1 is

890

−160

−890

−90

Q. The heat of formations for $C O_{2} (g), H_{2} O (l)$ and $C H_{4} (g)$ are $- 400 k J m o l^{- 1}$ , $- 280 K J m o l^{- 1}$ and $- 70 K J m o l^{- 1}$ respectively. The heat of combustion of $C H_{4}$ in $k J m o l^{- 1}$ is

$890$

$- 160$

$- 890$

$- 90$