Question

In an endothermic reaction, the value of change in enthalpy $(\Delta H)$ is

• A. positive
• B. zero
• C. negative
• D. either (b) or (c)

Answer 1

Answer: (A)

positive

Answer 2

In endothermic reaction , the enthalpy of reactants is less than the enthalpy of products, since heat is absorbed in endothermic reaction. Therefore, in endothermic reaction change in enthalpy is always positive. ${A + B <=> C + D \, \, \Delta H = + ve }$ $H_R \, H_P$ $\Delta H = H_P - H_R = + ve \, (\because \, H_P > H_R)$