Final answer:
For the chemical reaction AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq), a one-to-one molar ratio indicates that one molecule of NaCl is used for every molecule of AgNO3. Therefore, the correct answer is (A) 1 molecule of NaCl.
Step-by-step explanation:
The question pertains to the stoichiometry of a chemical reaction between silver nitrate (AgNO3) and sodium chloride (NaCl). From the balanced chemical equation given,
AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq),
it is seen that there is a one-to-one molar ratio between AgNO3 and NaCl. Therefore, for every molecule of AgNO3, one molecule of NaCl is used. Hence, the answer to the question 'How many molecules of NaCl are used in the reaction?' is (A) 1.