Give balanced equations to show the preparation of hydrogen by the following:
alkali

Explanation

To prepare hydrogen gas using an alkali, we can take sodium (Na) as an example of an alkali metal. The reaction occurs when sodium reacts with water. Here’s the step-by-step solution to write the balanced equation for this reaction:

### Step 1: Identify the Reactants
The reactants in this reaction are sodium (Na) and water (H₂O).

### Step 2: Write the Unbalanced Equation
The unbalanced equation for the reaction is:
\[ \text{Na} + \text{H}_2\text{O} \rightarrow \text{NaOH} + \text{H}_2 \]
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