When oxalic acid is heated with glycerol we get :

Options

A. Formic acid
B. Acetic acid
C. Lactic acid
D. Tartaric acid

Explanation

To solve the question "When oxalic acid is heated with glycerol, we get:", we can follow these steps:

### Step 1: Identify the Reactants
- The reactants in this reaction are oxalic acid and glycerol.
- Oxalic acid is a dicarboxylic acid with the formula \( \text{C}_2\text{H}_2\text{O}_4 \) or \( \text{HOOC-COOH} \).
- Glycerol is a triol with the formula \( \text{C}_3\text{H}_8\text{O}_3 \).

**Hint:** Remember the chemical formulas of the reactants involved in the reaction.

### Step 2: Understand the Reaction Conditions
- The reaction occurs upon heating, typically at temperatures around 100 to 110 degrees Celsius.
- Heating can lead to dehydration or elimination reactions, where water or other small molecules are removed.

**Hint:** Consider what happens to molecules when they are heated, especially in organic reactions.

### Step 3: Analyze the Reaction Mechanism
- When oxalic acid is heated with glycerol, one of the carboxyl groups (\( \text{-COOH} \)) from oxalic acid is eliminated.
- This elimination results in the formation of a new compound from the remaining part of oxalic acid and glycerol.

**Hint:** Think about what functional groups are left after the elimination of a carboxyl group.

### Step 4: Identify the Product
- After the elimination of one \( \text{-COOH} \) group, the remaining structure resembles formic acid (\( \text{HCOOH} \)).
- Therefore, the product formed from the reaction of oxalic acid and glycerol upon heating is formic acid.

**Hint:** Recall the structure of formic acid and how it relates to the reactants.

### Step 5: Verify Other Options
- Check the other options provided:
- **Acetic acid** (\( \text{CH}_3\text{COOH} \)) is not formed.
- **Lactic acid** has a hydroxy group and does not match the expected product.
- **Tartaric acid** is also not formed in this reaction.

**Hint:** Eliminate options by comparing their structures with the expected product.

### Conclusion
- The correct answer to the question is **formic acid**.

**Final Answer:** Formic acid (Option A).