Question

при взаимодействии 16 г технического zn, содержащего 5% примесей с 10% раствором hcl массой 200 г образовалась соль. найти ее массу, если ее практический выход = 90% от теоретического. пожалуйста помогите!!!!!

Answer 1

Ответ:

34

Объяснение:

обычная задача на избыток и недостаток

Answer 2

Calculation of the Mass of the Salt

To find the mass of the salt formed during the interaction of 16 g of a technical zn containing 5% impurities with a 10% solution of HCl weighing 200 g, we can follow these steps:

Step 1: Calculate the amount of zinc (Zn) in the technical zn sample. - The technical zn sample contains 5% impurities, so the pure zinc content is 100% - 5% = 95%. - Therefore, the mass of pure zinc in the sample is 16 g * (95% / 100%) = 15.2 g.

Step 2: Calculate the moles of zinc (Zn). - The molar mass of zinc (Zn) is 65.38 g/mol. - Therefore, the number of moles of zinc is 15.2 g / 65.38 g/mol = 0.2325 mol.

Step 3: Calculate the moles of hydrochloric acid (HCl). - The concentration of the HCl solution is 10%. - This means that 100 mL of the solution contains 10 g of HCl. - Therefore, the number of moles of HCl in 200 g of the solution is 200 g * (10 g/100 g) / 36.46 g/mol = 0.5488 mol.

Step 4: Determine the limiting reactant. - To determine the limiting reactant, we compare the moles of zinc (0.2325 mol) with the moles of HCl (0.5488 mol). - The reactant with the smaller number of moles is the limiting reactant. - In this case, zinc (Zn) is the limiting reactant.

Step 5: Calculate the theoretical yield of the salt. - The balanced chemical equation for the reaction between zinc (Zn) and hydrochloric acid (HCl) is: Zn + 2HCl -> ZnCl2 + H2 - From the equation, we can see that 1 mole of zinc (Zn) reacts to form 1 mole of the salt, ZnCl2. - Therefore, the theoretical yield of the salt is 0.2325 mol.

Step 6: Calculate the actual yield of the salt. - The practical yield is given as 90% of the theoretical yield. - Therefore, the actual yield of the salt is 0.9 * 0.2325 mol = 0.2093 mol.

Step 7: Calculate the mass of the salt. - The molar mass of ZnCl2 is 136.29 g/mol. - Therefore, the mass of the salt is 0.2093 mol * 136.29 g/mol = 28.51 g.

The mass of the salt formed is approximately 28.51 grams.

Please note that this calculation assumes that the reaction goes to completion and that there are no other side reactions or losses during the process.