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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