If the value of ΔH is positive for a reaction; it means that the reaction is?

A. exothermic
B. endothermic
C. spontaneous
D. slow

Correct Answer:

Option B – endothermic

Explanation

– Endothermic reactions are chemical reactions in which the reactants absorb heat energy from the surroundings to form products.

– A system of reactants that absorbs heat from the surroundings in an endothermic reaction has a positive ΔH.

– examples of endothermic processes:

Melting ice cubes.
Melting solid salts.
Sublimation of dry ice into carbon dioxide gas.
Evaporating liquid water.