1 gram of hydrated oxalic acid [( COOH )2 ⋅ 2 H 2 O ] undergoes combustion it produces 2.2 kcal of heat. What will be its enthalpy of combustion ( Δ Hc )?

Question

1 gram of hydrated oxalic acid [( COOH )2 ⋅ 2 H 2 O ] undergoes combustion it produces 2.2 kcal of heat. What will be its enthalpy of combustion ( Δ Hc )? (A) -2.2 kcal (B) -126 kcal (C) -277.2 kcal (D) -423 kcal

Tardigrade Admin · Accepted Answer

Combustion enthalpy is the amount of energy released during complete combustion of one mole of the reactant in the presence of the oxygen.

It is always negative as per the thermodynamic sign convention.

The molar mass of the hydrated oxalic acid is

= 126 g m o l^{- 1}

1 g \to - 2.2 k c a l

126 g \to - 2.2 \times 126 k c a l = - 277.2 k c a l

Q. $1$ gram of hydrated oxalic acid $[(COO H)_{2} \cdot 2 H_{2} O]$ undergoes combustion it produces $2.2 k c a l$ of heat. What will be its enthalpy of combustion ( $Δ H_{c}$ )?

$- 2.2 k c a l$

$- 126 k c a l$

$- 277.2 k c a l$

$- 423 k c a l$

Q. 1 gram of hydrated oxalic acid [(COOH)2​⋅2H2​O] undergoes combustion it produces 2.2kcal of heat. What will be its enthalpy of combustion ( ΔHc​ )?

−2.2kcal

−126kcal

−277.2kcal

−423kcal

Q. $1$ gram of hydrated oxalic acid $[(COO H)_{2} \cdot 2 H_{2} O]$ undergoes combustion it produces $2.2 k c a l$ of heat. What will be its enthalpy of combustion ( $Δ H_{c}$ )?

$- 2.2 k c a l$

$- 126 k c a l$

$- 277.2 k c a l$

$- 423 k c a l$