Question

If the bond energies of H–H, Br – Br and H –Br are 433, 192 and 364 kJ mol–1 respectively the ∆Hº for the reaction H2(g) + Br2(g) $\rightarrow$2HBr(g)

• A. + 103 kJ
• B. 261kJ
• C. –103 kJ
• D. –261 kJ

Answer 1

Answer: (C)

–103 kJ

Answer 2

∆Hº for the reaction H2(g) + Br2(g)$\rightarrow$ 2HBr(g) is -177 kJ/mol.