What must be true for any endothermic reaction?

The chemical bonds of the products have more energy than the chemical bonds of the reactants.

There are more products than there are reactants.

There must be a phase change from solid to liquid or from liquid to gas.

The reaction must take place in a sealed container held at constant volume.

Question

What must be true for any endothermic reaction?

 The chemical bonds of the products have more energy than the chemical bonds of the reactants.

 There are more products than there are reactants.

 There must be a phase change from solid to liquid or from liquid to gas.

 The reaction must take place in a sealed container held at constant volume.

festinger · Answer

The first option.

I cannot recall what endothermic reaction is, but i've always associated it with cooling, that is, it extracts energy from the surroundings.

This would only happen if the chemical bonds of the products have more energy than that of the reactants.

Think of the reactant bonds have 3 candy. But the product bonds have 5 candy. The reactant bonds need to get 2 more candy from somewhere, and thus they take it from the surroundings.