Question

exam lesson name: chemistry
exam number: 700700rr
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question 9 of 20 :
select the best answer for the question.

1. in the chemical equation zn + 2hcl → zncl + h, the reactants are

○ a. zinc and hydrogen carbonate.
○ b. zinc chlorate and water.
○ c. zinc and hydrochloric acid.
○ d. zinc chloride and hydrogen.
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Explanation:

In a chemical equation, reactants are the substances on the left - hand side of the arrow. In the given equation $\ce{Zn + 2HCl -> ZnCl_2 + H_2}$ (note: there was a typo in the original equation, the correct product for zinc and hydrochloric acid reaction is $\ce{ZnCl_2}$ and $\ce{H_2}$), the substances on the left are $\ce{Zn}$ (zinc) and $\ce{HCl}$ (hydrochloric acid).

• Option A: Hydrogen carbonate is $\ce{H_2CO_3}$, not present in the reactants.
• Option B: Zinc chlorate is $\ce{Zn(ClO_3)_2}$ and water is $\ce{H_2O}$, neither are reactants here.
• Option D: Zinc chloride ($\ce{ZnCl_2}$) and hydrogen ($\ce{H_2}$) are products (on the right - hand side of the arrow), not reactants.

Answer:

C. zinc and hydrochloric acid.