To reverse a reaction in a Hess's law problem, you need to change the sign of the enthalpy change associated with that reaction. If the original reaction has an enthalpy of reaction ( \Delta H ), the final value for the enthalpy of the reversed reaction would be ( -\Delta H ). This allows you to correctly account for the energy change in the overall pathway when combining reactions.
The final value for the enthalpy of reaction for the combustion of ethylene (C2H4) in your given reaction is -1410 kJ. This indicates that the reaction is exothermic, releasing 1410 kJ of energy as products (2 CO2 and 2 H2O) are formed from the reactants (C2H4 and 3 O2). Therefore, the enthalpy change, ΔH, for the complete combustion of ethylene is -1410 kJ.
... Intermediate equations with known enthalpies are added together.
... Intermediate equations with known enthalpies are added together.
The enthalpy of a chemical reaction is the change of heat during this reaction.
If you need to multiply the reaction by 2, you must also multiply the enthalpy change by 2. The final value for the enthalpy of the reaction used for the intermediate reaction would be 2 times the original enthalpy value.
-572k
When you multiply a reaction by a factor, you also multiply the enthalpy change by the same factor. Therefore, if you multiply the reaction by 2, the final value for the enthalpy of reaction for the intermediate reaction will also be multiplied by 2.
Can you please provide me with the specific reaction or context for which you need the enthalpy value?
It is multiplied by 2 if the intermediate reaction is multiplied by 2
The final value for the enthalpy of the reverse reaction used in a Hess's law problem would simply be the negative of the original value of the enthalpy of the forward reaction. This is because reversing a reaction changes the sign of the enthalpy change.
286 kJ
The enthalpy of a reaction does not depend on the reactant path taken.
The enthalpy of a reaction is the sum of the enthalpies of intermediate reaction.
To reverse a reaction in a Hess's law problem, you need to change the sign of the enthalpy change associated with that reaction. If the original reaction has an enthalpy of reaction ( \Delta H ), the final value for the enthalpy of the reversed reaction would be ( -\Delta H ). This allows you to correctly account for the energy change in the overall pathway when combining reactions.
If you need to reverse a reaction and multiply it by 2 in Hess's law, the enthalpy change of the reaction will also change sign and double in magnitude. This is because reversing a reaction changes the sign of the enthalpy change. Multiplying the reaction by a factor also multiplies the enthalpy change by that factor. Therefore, the final value for the enthalpy of the reaction will be twice the original magnitude but with the opposite sign.
2820 kJ