The value of ΔH° for the reaction below is -72 kJ. __________ kJ of heat are released when 4.0 mol of HBr is formed in this reaction. H₂ (g)+ Br₂ (g)→ 2HBr (g)

Question

Quizplus · Accepted Answer

The given ΔH° value (-72 kJ) is the heat released for the formation of 2 moles of HBr. Therefore, the heat released for the formation of 1 mole of HBr can be calculated by dividing -72 kJ by 2, which gives -36 kJ/mol. 
To find the heat released for the formation of 4 moles of HBr, we need to multiply -36 kJ/mol by 4, which gives -144 kJ. However, since we are looking for the absolute value of the heat released, we take the magnitude of -144 kJ, which is 144 kJ. 
Therefore, the correct answer is D) 144 kJ.

The Value of ΔH° for the Reaction Below Is -72