What is the sign of the enthalpy change, $Δ H$ , for an exothermic reaction?

Practise more Thermochemistry.

Free questions with an explanation for every one, and full timed Leaving Cert Ireland mock tests.

All Thermochemistry questions Take a mock test

More Thermochemistry questions

Using the bond energies (kJ/mol) H–H 436, Cl–Cl 243, H–Cl 432, estimate the enthalpy change for H $_{2}$ + Cl $_{2}$ → 2HCl.
When 0.5 mol of methane is burned completely, 445 kJ of heat is released. What is the heat of combustion of methane?
Given C + O $_{2}$ $\to$ CO $_{2}$ , $Δ H = - 394$ kJ/mol, and CO + $\frac{1}{2}$ O $_{2}$ $\to$ CO $_{2}$ , $Δ H = - 283$ kJ/mol…