Which of the following is correct for the reaction?
`Cu + HCl to`

Options

A. React vigorously
B. No reaction
C. React moderately
D. React slowly

Explanation

To determine the correct statement regarding the reaction of copper (Cu) with hydrochloric acid (HCl), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**: The reactants in this reaction are copper (Cu) and hydrochloric acid (HCl).

2. **Understand the Reactivity Series**: The reactivity series is a list of metals arranged in order of decreasing reactivity. Metals that are higher in the series can displace those that are lower from their compounds.

3. **Locate Copper and Hydrogen in the Reactivity Series**: In the reactivity series, copper is positioned below hydrogen. This means that copper is less reactive than hydrogen.

4. **Analyze the Reaction**: When a metal reacts with an acid, it generally displaces hydrogen from the acid to form a salt and hydrogen gas. However, since copper is less reactive than hydrogen, it cannot displace hydrogen from hydrochloric acid.

5. **Conclusion**: Since copper cannot displace hydrogen from hydrochloric acid, the reaction does not occur. Therefore, the correct statement regarding the reaction of copper with hydrochloric acid is "no reaction."

### Final Answer:
The correct statement for the reaction of Cu + HCl is: **No reaction.**

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