Ответ: 2H₃PO₄ + 3K₂S = 2K₃PO₄ + 3H₂S↑6H⁺+2PO₄³⁻ + 6K⁺ + 3S²⁻ = 6K⁺ + 2PO₄³⁻ + 3H₂S6H⁺ + 3S⁻² = 3H₂S2H⁺+S²⁻=H₂S