500 " mL of " 1.0 M `H_2C_2O_4`, 100 " mL of " 2.0 M `H_2SO_4`, and `40 g` of `NaOH` are mixed together, 30 " mL of " the above mixture is titrated against a standard solution of sodium carbonate containing 14.3 g of `Na_2CO_3.10H_2O` per 100 " mL of " solution. Find the volume of carbonate solution used for complete neutralisation.

Explanation

To solve the problem step-by-step, we will calculate the milliequivalents of the acids and bases involved, and then determine the volume of sodium carbonate solution needed for complete neutralization.

### Step 1: Calculate the milliequivalents of `H2C2O4`
- **Given:** Volume = 500 mL, Molarity = 1.0 M
- **Formula:** Milliequivalents = Molarity × Volume (in L) × n (number of acidic protons)
- `H2C2O4` has 2 acidic protons (n = 2).

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