# Two solutions of nitric acid were mixed: 140 g of 10% and 160 g of 25%. Find the mass fraction of acid in the resulting solution. Given: m1 (solution) = 140 g,: ω1 (acid) = 10%, or 0.1, m2 (solution) = 160 g, ω2 (acid) = 25%, or 0.25.
Find: ω (acid) -?
Decision.
1. Calculate the mass of the solute (acid) in the first solution:
m1 (acid) = m1 (solution) • ω1 (acid) = 140 g • 0.1 = 14 g.
2. Calculate the mass of the solute (acid) in the second solution:
m2 (acid) = m2 (solution) • ω2 (acid) = 160 g • 0.25 = 40 g.
3. Calculate the mass of the solute (acid) in the resulting solution:
m (acids) = m1 (acids) + m2 (acids) = 14 g + 40 g = 54 g.
3. Calculate the mass of the resulting solution:
m (solution) = m1 (solution) + m2 (solution) = 140 g + 160 g = 300 g.
4. Calculate the mass fraction of the solute (acid) in the resulting solution:
ω (acid) = m (acid) / m (solution) = 54 g: 300 g = 0.18, or,
multiplying this value by 100%, we get 18%. Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.