Missing questions:
a) How many milliliters of acid are in the resulting mixture?
b) What percentage of the resulting mixture is acid?
a) V₁ = 35 ml.
ω₁ = 18% = 0,18.
V₂ = 90 ml.
ω₂ = 68% = 0,68.
V(acid) = V₁ · ω₁ + V₂ · ω₂.
V(acid) = 35 ml · 0,18 + 90 ml · 0,68 = 67,5ml.
b) ω(acid) = 67,5 ml ÷ (35 ml + 90 ml).
ω(acid) = 54%.
