Question

Вариант № 1. 1)Составьте уравнения возможных реакций в молекулярном, полном ионном и сокращенном ионном виде: CaCl2 + K2CO3 →; NaNO3 + MgCl2 →; K2SiO3 + HCl →; H3PO4 + NaOH→. 2)Определите характер среды в растворах следующих солей. Для подтверждения составьте уравнения реакций гидролиза: а) K2S; b) Al2(SO4)3; c) CaCl2. 3) Определите массу сульфата натрия, который образуется при взаимодействии растворов, содержащих 12 г гидроксида натрия и 19,6 г серной кислоты. Внимание! Третье задание при помощи нахождения ню. Нужна помощь. 55 балов

Answer 1

Смогла решить только первое задание

Answer 2

Equations for Reactions in Molecular, Complete Ionic, and Net Ionic Forms:

1) The equations for the reactions in molecular, complete ionic, and net ionic forms are as follows:

a) CaCl2 + K2CO3 → CaCO3 + 2KCl

Molecular equation: CaCl2 + K2CO3 → CaCO3 + 2KCl

Complete ionic equation: Ca^2+(aq) + 2Cl^-(aq) + 2K^+(aq) + CO3^2-(aq) → CaCO3(s) + 2K^+(aq) + 2Cl^-(aq)

Net ionic equation: Ca^2+(aq) + CO3^2-(aq) → CaCO3(s)

b) NaNO3 + MgCl2 → Mg(NO3)2 + 2NaCl

Molecular equation: NaNO3 + MgCl2 → Mg(NO3)2 + 2NaCl

Complete ionic equation: Na^+(aq) + NO3^-(aq) + Mg^2+(aq) + 2Cl^-(aq) → Mg(NO3)2(aq) + 2Na^+(aq) + 2Cl^-(aq)

Net ionic equation: Mg^2+(aq) + 2NO3^-(aq) → Mg(NO3)2(aq)

c) K2SiO3 + 2HCl → 2KCl + H2SiO3

Molecular equation: K2SiO3 + 2HCl → 2KCl + H2SiO3

Complete ionic equation: 2K^+(aq) + SiO3^2-(aq) + 2H^+(aq) + 2Cl^-(aq) → 2K^+(aq) + 2Cl^-(aq) + H2SiO3(aq)

Net ionic equation: SiO3^2-(aq) + 2H^+(aq) → H2SiO3(aq)

d) H3PO4 + 3NaOH → Na3PO4 + 3H2O

Molecular equation: H3PO4 + 3NaOH → Na3PO4 + 3H2O

Complete ionic equation: 3H^+(aq) + PO4^3-(aq) + 3Na^+(aq) + 3OH^-(aq) → Na3PO4(aq) + 3H2O(l)

Net ionic equation: 3H^+(aq) + PO4^3-(aq) → Na3PO4(aq) + 3H2O(l)

Character of the Solutions and Hydrolysis Reactions:

2) The character of the solutions and hydrolysis reactions for the given salts are as follows:

a) K2S: The salt K2S is a strong electrolyte and completely dissociates into ions in water. The hydrolysis reaction can be represented as follows:

K2S + H2O → 2KOH + H2S

b) Al2(SO4)3: The salt Al2(SO4)3 is also a strong electrolyte and completely dissociates into ions in water. The hydrolysis reaction can be represented as follows:

Al2(SO4)3 + 6H2O → 2Al(OH)3 + 3H2SO4

c) CaCl2: The salt CaCl2 is a strong electrolyte and completely dissociates into ions in water. The hydrolysis reaction can be represented as follows:

CaCl2 + 2H2O → Ca(OH)2 + 2HCl

Calculation of Sodium Sulfate Mass:

3) To determine the mass of sodium sulfate formed when 12 g of sodium hydroxide and 19.6 g of sulfuric acid react, we need to calculate the number of moles of each reactant and then determine the limiting reactant.

The balanced equation for the reaction between sodium hydroxide (NaOH) and sulfuric acid (H2SO4) is:

2NaOH + H2SO4 → Na2SO4 + 2H2O

Using the molar masses of NaOH (40 g/mol) and H2SO4 (98 g/mol), we can calculate the number of moles of each reactant:

Number of moles of NaOH = 12 g / 40 g/mol = 0.3 mol Number of moles of H2SO4 = 19.6 g / 98 g/mol = 0.2 mol

From the balanced equation, we can see that the stoichiometric ratio between NaOH and H2SO4 is 2:1. Therefore, 0.2 mol of H2SO4 requires 0.4 mol of NaOH for complete reaction.

Since we have only 0.3 mol of NaOH, it is the limiting reactant. This means that all of the NaOH will be consumed in the reaction, and the amount of sodium sulfate formed will be determined by the amount of NaOH.

The molar mass of sodium sulfate (Na2SO4) is 142 g/mol. Therefore, the mass of sodium sulfate formed can be calculated as follows:

Mass of sodium sulfate = 0.3 mol * 142 g/mol = 42.6 g

Therefore, the mass of sodium sulfate formed when 12 g of sodium hydroxide and 19.6 g of sulfuric acid react is 42.6 g.

I hope this helps! Let me know if you have any further questions.