Question

Цинк массой 6.5 г. растворили в 300 г. раствора кислоты с массовой долей HCl 36.5%. Найти массовую долю соли в полученном растворе

Answer 1

Zn+ 2HCl= ZnCl2 +H2
v(Zn)=6.5/65=0.1 моль
v(HCl)=300*36.5/100*36.5= 3 моль
 m(ZnCl2)=0.1*136=13.6 г
m(H2)=0.1*2=0.2 г
m(раствора)=300+6,5-0,2=306,3 г
w(ZnCl2)=13.6*100/306.3= 4.44

Answer 2

Calculation of the Mass Fraction of Salt in the Solution

To find the mass fraction of salt in the solution, we need to calculate the mass of the salt and the total mass of the solution.

Given: - Mass of zinc (Zn) = 6.5 g - Mass of hydrochloric acid (HCl) solution = 300 g - Mass fraction of HCl in the solution = 36.5%

To calculate the mass of the salt (ZnCl2) formed, we need to determine the moles of zinc and hydrochloric acid.

1. Calculate the moles of zinc (Zn): - Molar mass of zinc (Zn) = 65.38 g/mol - Moles of zinc (Zn) = Mass of zinc (Zn) / Molar mass of zinc (Zn)

2. Calculate the moles of hydrochloric acid (HCl): - Molar mass of hydrochloric acid (HCl) = 36.46 g/mol - Moles of hydrochloric acid (HCl) = (Mass of hydrochloric acid (HCl) solution * Mass fraction of HCl) / Molar mass of HCl

3. Determine the limiting reactant: - The limiting reactant is the reactant that is completely consumed and determines the amount of product formed. In this case, the limiting reactant is the one that produces the least amount of product. - To determine the limiting reactant, compare the moles of zinc (Zn) and hydrochloric acid (HCl) and identify the reactant with the smaller number of moles.

4. Calculate the moles of salt (ZnCl2) formed: - The balanced chemical equation for the reaction between zinc (Zn) and hydrochloric acid (HCl) is: Zn + 2HCl → ZnCl2 + H2 - From the balanced equation, we can see that 1 mole of zinc (Zn) reacts with 2 moles of hydrochloric acid (HCl) to form 1 mole of salt (ZnCl2). - Moles of salt (ZnCl2) = Moles of limiting reactant * (1 mole of salt / 1 mole of zinc)

5. Calculate the mass of the salt (ZnCl2): - Mass of salt (ZnCl2) = Moles of salt (ZnCl2) * Molar mass of salt (ZnCl2)

6. Calculate the total mass of the solution: - Total mass of the solution = Mass of zinc (Zn) + Mass of hydrochloric acid (HCl) solution

7. Calculate the mass fraction of the salt (ZnCl2) in the solution: - Mass fraction of salt (ZnCl2) = Mass of salt (ZnCl2) / Total mass of the solution

Let's perform the calculations.