Calculate the mass fraction of potassium hydroxide in a solution with a density of 1035 g / l, if 2.45 ml of 20% hydrochloric acid with a density of 1100 g / l are used to neutralize 20 ml of solution.
KOH + HCl → KCl + H2O
n (HCl) = (2.45 x 0.2 x 1.1) / 36.5 = 0.0148 mol
⇒ n (KOH) = 0.0148 mol
n (KOH) = (ω x ρ x V) / Mr
⇒ 0.0148 = (ω x 20 x 1.035) / (39 + 17)
⇒ ω = 0.04 or 4%
Answer: the mass fraction of potassium hydroxide in the solution is 4%.
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