Question

Which of the following relations are correct if $\Delta H$ represents only magniude ?

• A. Exithermic reactions : $E_{a\left(f\right)}+\Delta H=E_{a\left(b\right)}$
• B. Endothermic reactions : $E_{a\left(f\right)}=E_{a\left(b\right)}+\Delta H$
• C. Exothermic reactions : $\Delta H>E_a$
• D. Endothermic reactions : $\Delta H<E_a$

Answer 1

Answer: (A), (B), (D)

Exithermic reactions : $E_{a\left(f\right)}+\Delta H=E_{a\left(b\right)}$
Endothermic reactions : $E_{a\left(f\right)}=E_{a\left(b\right)}+\Delta H$
Endothermic reactions : $\Delta H<E_a$

As we know,
For any reaction, $\Delta H=E_{a\left(f\right)}-E_{a\left(b\right)}$