Question

If 3 moles of a compound use 12 J of energy in a reaction, what is the Hreaction in kJ/mol

Answer 1

on ap ex the answer would be 0.004 kJ/mol

Answer 2

`\Delta _RH=4x10^(-3)(kJ)/(mol)`

Step-by-step explanation:

Hello,

In this case, the molar enthalpy of reaction is obtained by dividing the involved energy by the reacting moles:

`\Delta _RH=(12J)/(3mol) =4(J)/(mol)`

Thus, it is important to notice that the compound "uses" the energy, it means that it absorbs the energy, for that reason the sign is positive. Moreover, computing the result in kJ/mol we finally obtain:

`\Delta _RH=4(J)/(mol)*(1kJ)/(1000J) =4x10^(-3)(kJ)/(mol)`

Best regards.