Define an acid and base according to Arrhenius theory .

Explanation

### Step-by-Step Text Solution:

1. **Definition of Arrhenius Acid**:
- An Arrhenius acid is defined as a substance that, when dissolved in water, increases the concentration of hydrogen ions (H⁺) in the solution.
- For example, hydrochloric acid (HCl) dissociates in water to produce H⁺ ions and chloride ions (Cl⁻):
\[ \text{HCl} \rightarrow \text{H}^+ + \text{Cl}^- \]
...