Question

exam lesson name: chemistry
exam number: 700700rr
exam guidelines
exam instructions
question 16 of 20 :
select the best answer for the question.

1. a chemical reaction in which compounds break up into simpler constituents is a ______ reaction.

a. decomposition
b. double replacement
c. substitution
d. combination
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Explanation:

To solve this, we analyze each option:

• Option A: Decomposition reactions involve a compound breaking down into simpler substances (e.g., \( \ce{2H_2O_2 -> 2H_2O + O_2} \)). This matches the description.
• Option B: Double replacement reactions involve the exchange of ions between two compounds (e.g., \( \ce{AgNO_3 + NaCl -> AgCl + NaNO_3} \)), not breaking into simpler constituents.
• Option C: Substitution (or single - replacement) reactions involve one element replacing another in a compound (e.g., \( \ce{Zn + 2HCl -> ZnCl_2 + H_2} \)), not compound breakdown.
• Option D: Combination reactions involve substances combining to form a more complex compound (e.g., \( \ce{H_2 + O_2 -> H_2O} \)), the opposite of breakdown.

Answer:

A. decomposition