Consider the following statements regarding chemical reactions and choose the correct option. Statement I: Every reaction in which two or more reactants combine to form a single product is classified as a combination reaction regardless of heat change. Statement II: The reaction CaO(s) + H O(l) → Ca(OH) (aq) + heat is both a combination 2 2 reaction and an exothermic reaction.
Both statements are correct
Evaluating both statements:
Statement I: “Every reaction where two or more reactants combine to form a single product is classified as a combination reaction regardless of heat change.”
✓ Correct. A combination (synthesis) reaction is defined purely by its form: A + B → AB. Heat change (endo or exo) does not affect this classification.
Statement II: “CaO(s) + H2O(l) → Ca(OH)2(aq) + heat is both a combination reaction and an exothermic reaction.”
✓ Correct. Quicklime (CaO) reacting with water is a combination reaction (two reactants → one product) that releases substantial heat (exothermic — slaking of lime).
Both statements are correct → Option 1.
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