0.45 g of a dibasic acid on combustion gave 0.44 g of `CO_2` and 0.09 g `H_2 O`. The molecular mass of the acid is 90. Calculate the molecular formula. Suggest a structure for the acid.

Explanation

To solve the problem, we need to determine the molecular formula of the dibasic acid based on the combustion data provided. Here's a step-by-step solution:

### Step 1: Calculate moles of CO₂ and H₂O produced
- **Given:**
- Mass of CO₂ = 0.44 g
- Mass of H₂O = 0.09 g
- **Molar Masses:**
- Molar mass of CO₂ = 44 g/mol
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