To 850 ml of a potassium nitrate solution with a mass fraction of 10% salt was added 100 ml

To 850 ml of a potassium nitrate solution with a mass fraction of 10% salt was added 100 ml of water. What is the mass fraction of potassium nitrate in the resulting solution?

1. Determine the volume of pure potassium nitrate in solution:
To begin with, we write down an expression to determine the mass fraction of a substance in a solution:
w (in-va) = (m (in-va) / m (solution)) * 100% = (V (in-va) / V (solution)) * 100%
Let us express the volume of matter from this expression:
V (in-va) = (w (in-va) * V (solution)) / 100% = 10 * 850/100 = 85 ml.
2. When adding water, the volume of the resulting solution changed:
V1 (solution) = V (solution) + V (H2O) = 850 + 100 = 950 ml.
3. Determine the mass fraction of potassium nitrate in the resulting solution:
w1 (v-va) = (V (v-va) / V1 (r-ra)) * 100% = (85/950) * 100% = 8.94%.
Answer: the mass fraction became 8.94%.