The number of compounds which are more acidic than benzoic acid amongst :o-nitrobenzoic acid, p-chlorobenzoic acid, p-methoxybenzoic acid, p-toluic acid, o-toluic acid, acetic acid, o-hydroxybenzoic acid are:

Explanation

To determine the number of compounds that are more acidic than benzoic acid among the given options, we need to analyze the effect of different substituents on the acidity of benzoic acid derivatives.

### Step-by-Step Solution:

1. **Identify the Acidity of Benzoic Acid**:
- Benzoic acid (C6H5COOH) has a certain acidity level, which we will use as a reference point.

2. **Understand the Effect of Substituents**:
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