M(р-ра) = 68=12=80
w \%(соли) = 12/80 * 100 = 15\%
K₂CO₃ + 2HCl = 2KCl + CO₂ + H₂O
2K⁺ + CO₃²⁻ + 2H⁺ + 2Cl⁻ = 2K⁺ + 2Cl⁻ + CO₂ + H⁺ + OH⁻
CO₃²⁻ + H⁺ = CO₂ + OH⁻
n(Na3PO4) = 820/164 = 5 моль
n(CaHPO4) =n(Na3PO4) = 5 моль
m(CaHPO4) =136* 5 = 680 г
CH2(Cl)-CH2-COOH
CH3-CH(Cl)-COOH
CH3-CH(F)-COOH