Question

Слили растворы сульфата цинка и гидроксида калия. Масса ZnSO4-50 граммов,массовая доля-2 процента. Масса раствора KOH-40 граммов,масс.доля-8 проц. Образуется ли осадок при сливании растворов? Ур-ния ZnSO4+2KOH=Zn(OH)2+K2SO4 Zn(OH)2+2KOH=K2[Zn(OH)4]

Answer 1

ZnSO₄+2KOH=Zn(OH)₂+K₂SO₄

Zn(OH)₂+2KOH=K₂[Zn(OH)₄]

m(ZnSO₄) = 50 · 0,02 = 1 г

n(ZnSO₄) =  1 : 161 = 0,006 моль

m(KOH) = 40 · 0,08 = 3,2 г

n(KOH) =  3,2 : 56 = 0,057 моль - это почти в 100 раз больше, чем n(ZnSO₄), поэтому осадок не выпадет

Answer 2

Formation of Precipitate when Zinc Sulfate and Potassium Hydroxide Solutions are Mixed

When zinc sulfate (ZnSO4) and potassium hydroxide (KOH) solutions are mixed, a precipitation reaction can occur. The balanced chemical equation for this reaction is:

ZnSO4 + 2KOH → Zn(OH)2 + K2SO4 (Equation 1)

Zn(OH)2 + 2KOH → K2[Zn(OH)4] (Equation 2)

To determine if a precipitate will form when the solutions are mixed, we need to compare the solubility of the products with the initial concentrations of the reactants.

Solubility of Zinc Hydroxide (Zn(OH)2)

Zinc hydroxide (Zn(OH)2) is a sparingly soluble compound. According to the provided information, the mass of ZnSO4 is 50 grams, and its mass fraction is 2%. However, the mass of the ZnSO4 solution is not given. To determine the concentration of ZnSO4 in the solution, we need to know the volume of the solution.

Solubility of Potassium Hydroxide (KOH)

Potassium hydroxide (KOH) is a highly soluble compound. According to the provided information, the mass of KOH is 40 grams, and its mass fraction is 8%.

Conclusion

Without knowing the volume of the ZnSO4 solution, it is not possible to determine the concentration of ZnSO4 and predict if a precipitate will form when the solutions are mixed. The solubility of Zn(OH)2 is limited, and if the concentration of ZnSO4 is high enough, a precipitate of Zn(OH)2 may form. However, further calculations are needed to determine the exact conditions for precipitation.

Please provide the volume of the ZnSO4 solution so that we can proceed with the calculations and provide a more accurate answer.