Question

how to know a reaction is endothermic? class11-thermodynamics

Answer 1

Answer:

So if the sum of the enthalpies of the reactants is greater than the products, the reaction will be exothermic. If the products side has a larger enthalpy, the reaction is endothermic. You may wonder why endothermic reactions, which soak up energy or enthalpy from the environment, even happen.

Answer 2

Answer:

An endothermic process is any process which requires or absorbs thermal energy from its surroundings, usually in the form of heat.

So if the sum of the enthalpies of the reactants is greater than the products, the reaction will be exothermic. If the products side has a larger enthalpy, the reaction is endothermic.