To 200 g of a 20% KOH solution, 50 g of KOH was added. Calculate the mass fraction (in%)

To 200 g of a 20% KOH solution, 50 g of KOH was added. Calculate the mass fraction (in%) of potassium hydroxide in the resulting solution.

1. Let’s find the mass of KOH in solution:

m (KOH) = ω * m (solution) / 100% = 20 * 200/100% = 40g.

2. Let’s find a new mass of KOH:

m = 40 + 50 = 90g.

3. Find the new mass of the solution:

m = 200g + 50g = 250g.

4. Let’s find the mass fraction of potassium hydroxide:

ω (KOH) = 90/250 * 100% = 36%.

Answer: ω (KOH) = 36%.



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