H 2+1 / 2 O 2 arrow H 2 O ; Δ H ominus=-68 kcal K + H 2 O + aq arrow KOH ( aq )+1 / 2 H 2 ; Δ H ominus=-48 kcal KOH + aq arrow KOH ( aq ) ; Δ H ominus=-14 kcal From the above data, the standard heat of formation of KOH in kcal is

Question

H 2+1 / 2 O 2 arrow H 2 O ; Δ H ominus=-68 kcal K + H 2 O + aq arrow KOH ( aq )+1 / 2 H 2 ; Δ H ominus=-48 kcal KOH + aq arrow KOH ( aq ) ; Δ H ominus=-14 kcal From the above data, the standard heat of formation of KOH in kcal is (A) -68+48-14 (B) -68-48+14 (C) 68-48+14 (D) 68+48+14

Tardigrade Admin · Accepted Answer

Correct answer is (b) -68-48+14

Q. $H_{2} + 1/2 O_{2} \to H_{2} O; Δ H^{⊖} = - 68 k c a l$
$K + H_{2} O + a q \to K O H (a q) + 1/2 H_{2}; Δ H^{⊖} = - 48 k c a l$
$K O H + a q \to K O H (a q); Δ H^{⊖} = - 14 k c a l$
From the above data, the standard heat of formation of $K O H$ in kcal is

$- 68 + 48 - 14$

$- 68 - 48 + 14$

$68 - 48 + 14$

$68 + 48 + 14$

Correct answer is (b) $- 68 - 48 + 14$

Q. H2​+1/2O2​→H2​O;ΔH⊖=−68kcal K+H2​O+aq→KOH(aq)+1/2H2​;ΔH⊖=−48kcal KOH+aq→KOH(aq);ΔH⊖=−14kcal From the above data, the standard heat of formation of KOH in kcal is

−68+48−14

−68−48+14

68−48+14

68+48+14