Question

1. Какова масса полученного осадка при взаимодействии 80г 20% раствора гидроксида натрия с 80г сульфата меди (II)?

Answer 1

2NaOH + CuSO4 = Cu(OH)2 + Na2SO4
масса гидроксида натрия в растворе = 80*20/100 =16г
число моль гидроксида натрия = 16/(23+16+1) = 0,4 моль
число моль сульфата меди = 80/(64+32+16*4) = 0,5 моль => в недостатке гидроксид натрия, по нему ведем расчет
масса полученного остатка гидроксида меди = 0,4*(64+2+16*2)/2 = 19,6 г

Answer 2

Calculating the Mass of Precipitate

To calculate the mass of the precipitate formed when 80g of a 20% solution of sodium hydroxide reacts with 80g of copper(II) sulfate, we can use the stoichiometry of the reaction and the principles of chemical reactions.

The balanced chemical equation for the reaction between sodium hydroxide (NaOH) and copper(II) sulfate (CuSO4) is:

2NaOH + CuSO4 → Na2SO4 + Cu(OH)2

From the balanced chemical equation, we can see that 2 moles of NaOH react with 1 mole of CuSO4 to produce 1 mole of Cu(OH)2.

Given that the molar mass of NaOH is approximately 40g/mol and the molar mass of CuSO4 is approximately 160g/mol, we can proceed with the calculation.

Using the given information, we can calculate the amount of Cu(OH)2 formed and then determine its mass.

Calculation Steps

1. Calculate the number of moles of NaOH in 80g of 20% solution. 2. Use the stoichiometry of the reaction to find the moles of CuSO4 that react with the moles of NaOH. 3. Calculate the mass of Cu(OH)2 formed from the moles obtained in step 2.

Calculation

1. Calculate the moles of NaOH: - The molar mass of NaOH is 40g/mol. - The 20% solution means there are 20g of NaOH in 100g of solution. - Therefore, the moles of NaOH in 80g of the solution can be calculated as: - Moles = (80g / 40g/mol) * (20g / 100g) = 0.4 moles

2. Use stoichiometry to find moles of CuSO4: - From the balanced equation, 2 moles of NaOH react with 1 mole of CuSO4. - Therefore, the moles of CuSO4 that react with 0.4 moles of NaOH is: - Moles of CuSO4 = 0.4 moles * (1 mole CuSO4 / 2 moles NaOH) = 0.2 moles

3. Calculate the mass of Cu(OH)2 formed: - The molar mass of Cu(OH)2 is approximately 97.56g/mol. - Therefore, the mass of Cu(OH)2 formed is: - Mass = 0.2 moles * 97.56g/mol = 19.512g

The mass of the precipitate formed when 80g of a 20% solution of sodium hydroxide reacts with 80g of copper(II) sulfate is approximately 19.512g.