4. Heat required for boiling water is known as: a) heat of formation. b) heat of vapourization. c) heat of fusion. d) heat of solution.

Option B

Explanation:

The best answer to this question is option B "heat of vaporization." When you add heat to a pot of water and the water starts to boil the water starts boiling/vaporizing into a gas called water vapor. The heat transformation is also known as the heat of evaporation where it's the amount of energy required to heat a pot of water to it's boiling point where it starts evaporating.

Hope this helps.

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.