Calculate the standard enthalpy change for reaction, aligned & C ₂ H ₅ OH _ ( ) +3 O _ 2( ~g ) 2 CO _ 2( ~g ) +3 H ₂ O _ ( ) & If, & aligned _ f H ^ ( C ₂ H ₅ OH ) & =-280 ~kJ ~mol ⁻¹ _ f H ^ ( CO ₂ ) & =-390 ~kJ ~mol ⁻¹ _ f H ^ ( H ₂ O ) & =-285 ~kJ ~mol ⁻¹ aligned aligned

Step-by-step solution

The standard enthalpy change for the reaction C ₂ H ₅ OH _ ( ) + 3 O _ 2( g ) 2 CO _ 2( g ) + 3 H ₂ O _ ( ) is calculated using the formula H^ _ rxn = n H^ _ f ( products ) - m H^ _ f ( reactants ) Using the given enthalpies of formation: _ f H^ ( C ₂ H ₅ OH ) = -280 , kJ ,mol⁻¹ _ f H^ ( CO ₂) = -390 , kJ ,mol⁻¹ _ f H^ ( H ₂ O ) = -285 , kJ ,mol⁻¹ and noting that _ f H^ ( O ₂) = 0 , kJ ,mol⁻¹ for the elemental form. The sum for products is 2 (-390 , kJ ) + 3 (-285 , kJ ) = -780 - 855 = -1635 , kJ The sum for reacta