Determine the per cent concentration of a solution obtained by mixing `300g` of a `25%` and `400g` of a `40%` solution.

Answer

To determine the percent concentration of a solution obtained by mixing 300 g of a 25% solution and 400 g of a 40% solution, we can follow these steps:

### Step 1: Calculate the mass of solute in each solution.

1. **For the 25% solution:**
- Mass of the solution = 300 g
- Concentration = 25%
- Mass of solute = (Concentration/100) × Mass of solution
- Mass of solute = (25/100) × 300 g = 75 g

2. **For the 40% solution:**
- Mass of the solution = 400 g
- Concentration = 40%
- Mass of solute = (Concentration/100) × Mass of solution
- Mass of solute = (40/100) × 400 g = 160 g

### Step 2: Calculate the total mass of solute.

- Total mass of solute = Mass of solute from 25% solution + Mass of solute from 40% solution
- Total mass of solute = 75 g + 160 g = 235 g

### Step 3: Calculate the total mass of the mixed solution.

- Total mass of the mixed solution = Mass of 25% solution + Mass of 40% solution
- Total mass of the mixed solution = 300 g + 400 g = 700 g

### Step 4: Calculate the percent concentration of the mixed solution.

- Percent concentration = (Total mass of solute / Total mass of mixed solution) × 100
- Percent concentration = (235 g / 700 g) × 100 ≈ 33.57%

### Final Answer:
The percent concentration of the mixed solution is approximately **33.57%**.

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