In the presence of hydrogen ions , a zinc ion ________ reduced .

Explanation

To solve the question, "In the presence of hydrogen ions, a zinc ion ________ reduced," we need to analyze the chemical behavior of zinc ions in the presence of hydrogen ions.

### Step-by-step Solution:

1. **Understanding the Reaction**:
When zinc (Zn) reacts with hydrochloric acid (HCl), it produces zinc chloride (ZnCl2) and hydrogen gas (H2). The reaction can be represented as:
\[
Zn + 2HCl \rightarrow ZnCl2 + H2
...