A sample of magnisium metal containing some `MgO` as impurity was dissolved in 125 " mL of " 0.1 N `H_2SO_4`. The volume of `H_2` evolved at `27.3^@C` and 1 atm was 120.1 mL. The resulting solution was found to be 0.02 N with respect to `H_2SO_4`. Calculate (i) the weight of sample dissolved and (ii) the percentage by weight of Mg in the sample. Neglect any change in the volume of the solution (atomic weight of `Mg=24.3`).

Explanation

To solve the problem step by step, we will follow the outlined procedure based on the information provided in the question.

### Step 1: Calculate the volume of H2 at STP
We are given the volume of hydrogen gas evolved at certain conditions. We need to convert this volume to standard temperature and pressure (STP) conditions.

Given:
- Volume of H2 at 27.3°C and 1 atm = 120.1 mL
- Temperature at STP = 0°C = 273 K
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