For a reaction, the sum of the standard formation enthalpies of the products is $-820$ kJ/mol and that of the reactants is $-560$ kJ/mol. Compute the standard reaction enthalpy in kJ/mol.

Hints

Reaction enthalpy is products minus reactants.
Compute -820 - (-560).

Show the answer

-260 (answers within ±1 count)

Why

$\Delta H^\circ_{rxn} = -820 - (-560) = -260$ kJ/mol. Subtracting a negative is where sign errors creep in, and it is exothermic because the products sit lower than the reactants.

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For a reaction, the sum of the standard formation enthalpies of the products is −820-820−820 kJ/mol and that of the reactants is −560-560−560 kJ/mol. Compute the standard reaction enthalpy in kJ/mol.

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More questions on Enthalpy and Thermochemistry

For a reaction, the sum of the standard formation enthalpies of the products is $-820$ kJ/mol and that of the reactants is $-560$ kJ/mol. Compute the standard reaction enthalpy in kJ/mol.