Question

Use bond enthalpy values to calculate the enthalpy change for the following reaction. Then, label if the reaction is endothermic or exothermic. 1) CH4 (g) + Br2 (g) --> CH3Br (g) + HBr (g)​

Answer 1

Based on the bond energies given, the enthalpy change for the reaction of is -33 kJ and the reaction is exothermic.

What is the change in bond energy of a reaction?

The change in bond energy of a reaction is calculated using the formula below:

• change in bond energy = sum of energies of bonds broken - sum of energies of bonds formed

A reaction is exothermic if the change in bond energy is negative.

A reaction is endothermic if the change in bond energy is positive.

Given the bond enery values above:

sum of energies of bonds broken = 4 × C-H + Br-Br

sum of energies of bonds broken = 4 × 413 + 193 = 1845 kJ

sum of energies of bonds formed = 3 × C-H + C-Br + H-Br

sum of energies of bonds formed = 3 × 413 + 276 + 363 = 1878 kJ

Thus;

change in bond energy = 1845 - 1878 = -33 kJ

• The reaction is exothermic because the change in bond energy is negative.

Therefore, the enthalpy change for the reaction of is -33 kJ and the reaction is exothermic.

Learn more about enthalpy change at: brainly.com/question/11628413