Question

Рассчитайте массовую долю (в процентах) хлороводорода в 400г соляной кислоты, если в ней максимально растворяется 5,4г металлического алюминияС ПОДРОБНЫМ РЕШЕНИЕМ!

Answer 1

5,4г---------21,9г 
2Al+6HCl=2AlCl3+3H2 
54г----------219г 
w(HCl)=21,9/400*100%=5,475%

Answer 2

2Al + 6HCl= 2AlCl + 3H2

n(Al) = m/M = 5.4 г. / 27 г/моль = 0,2 моль 

n(HCl) = 0.6 моль

m(HCl) = M * n = 36.5 * 0.6 моль = 21,9 г.

w = m/V * 100% = 21.9 / 400 * 100% = 5.475 %

Ответ : 5,475%

 

 

 

 

 

 

 

 

Answer 3

Calculation of the Mass Fraction of Hydrochloric Acid

To calculate the mass fraction of hydrochloric acid (HCl) in a solution, we need to consider the amount of HCl and the total mass of the solution.

Given: - Mass of hydrochloric acid (HCl) = 400 g - Maximum amount of aluminum (Al) that can dissolve in the solution = 5.4 g

To find the mass fraction of HCl, we need to determine the mass of HCl and the total mass of the solution.

Calculation Steps:

Step 1: Calculate the mass of HCl: The balanced chemical equation for the reaction between aluminum (Al) and hydrochloric acid (HCl) is:

2 Al + 6 HCl → 2 AlCl3 + 3 H2

From the equation, we can see that 2 moles of Al react with 6 moles of HCl to produce 2 moles of AlCl3 and 3 moles of H2. The molar mass of HCl is approximately 36.46 g/mol.

To calculate the mass of HCl, we can use the following equation:

(5.4 g Al) × (6 mol HCl / 2 mol Al) × (36.46 g HCl / 1 mol HCl) = X g HCl

Step 2: Calculate the total mass of the solution: The total mass of the solution is the sum of the mass of HCl and the mass of the solvent (water). Since the problem does not provide information about the mass of the solvent, we will assume that the mass of the solvent is equal to the mass of the solution.

Total mass of the solution = 400 g (given)

Step 3: Calculate the mass fraction of HCl: The mass fraction of HCl is the ratio of the mass of HCl to the total mass of the solution, multiplied by 100 to express it as a percentage.

Mass fraction of HCl = (mass of HCl / total mass of the solution) × 100

Substituting the values into the equation:

Mass fraction of HCl = (X g HCl / 400 g) × 100

Solution:

To calculate the mass fraction of hydrochloric acid (HCl) in the solution, we need to determine the mass of HCl and the total mass of the solution.

Step 1: Calculate the mass of HCl: Using the given information, we can calculate the mass of HCl using the equation:

(5.4 g Al) × (6 mol HCl / 2 mol Al) × (36.46 g HCl / 1 mol HCl) = X g HCl

Calculating the value of X, we find:

(5.4 g Al) × (6 mol HCl / 2 mol Al) × (36.46 g HCl / 1 mol HCl) = 97.884 g HCl

Therefore, the mass of HCl is approximately 97.884 g.

Step 2: Calculate the total mass of the solution: The total mass of the solution is given as 400 g.

Total mass of the solution = 400 g

Step 3: Calculate the mass fraction of HCl: Using the values calculated in steps 1 and 2, we can calculate the mass fraction of HCl using the equation:

Mass fraction of HCl = (mass of HCl / total mass of the solution) × 100

Substituting the values into the equation:

Mass fraction of HCl = (97.884 g HCl / 400 g) × 100

Calculating the value, we find:

Mass fraction of HCl = 24.471%

Therefore, the mass fraction of hydrochloric acid (HCl) in the 400 g solution is approximately 24.471%.

Please note that the above calculation assumes that the mass of the solvent (water) is equal to the mass of the solution.