Mass fraction of salt in the solution obtained by merging 100 g of 5% solution with 300 g of 15% solution.

1) The mass of the solute in the first solution is: 100 * 5/100 = 5g.
2) The mass of the solute in the second solution is: 300 * 15/100 = 45g.
3) The mass of the solute after draining: 45 + 5 = 50g.
4) The mass of the solution after draining: 100 + 300 = 400g.
5) Find the mass fraction of salt in the solution after draining. To do this, divide the mass of the solute by the mass of the solution and multiply by one hundred percent: 50/400 * 100 = 12.5% – the answer.



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