Question

Дано: m (NaOH)=20 г, m (CuSO4)=32г. Найти: m(Cu(OH)2)-?​

Answer 1

m(Cu(OH)2)=64+16+1*2=82

Answer 2

To find the mass of Cu(OH)2 formed when NaOH reacts with CuSO4, we first need to determine the balanced chemical equation for the reaction. The reaction between NaOH (sodium hydroxide) and CuSO4 (copper(II) sulfate) produces Cu(OH)2 (copper(II) hydroxide) as a precipitate.

The balanced chemical equation for the reaction is as follows:

NaOH + CuSO4 → Cu(OH)2 + Na2SO4

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

Next, we need to calculate the number of moles of NaOH and CuSO4 present in the given masses.

Given: m (NaOH) = 20 g m (CuSO4) = 32 g

Step 1: Calculate moles of NaOH and CuSO4 using their molar masses.

The molar masses are as follows: Molar mass of NaOH (sodium hydroxide) = 23 g/mol (Na) + 16 g/mol (O) + 1 g/mol (H) = 40 g/mol Molar mass of CuSO4 (copper(II) sulfate) = 63.5 g/mol (Cu) + 32 g/mol (S) + 4 * 16 g/mol (O) = 159.5 g/mol

Number of moles of NaOH: moles of NaOH = m(NaOH) / Molar mass(NaOH) = 20 g / 40 g/mol = 0.5 mol

Number of moles of CuSO4: moles of CuSO4 = m(CuSO4) / Molar mass(CuSO4) = 32 g / 159.5 g/mol ≈ 0.201 mol

Step 2: Determine the limiting reactant.

The stoichiometric ratio between NaOH and CuSO4 in the balanced equation is 2:1. The reactant that produces fewer moles of the product will be the limiting reactant.

From the balanced equation, 1 mole of CuSO4 produces 1 mole of Cu(OH)2, while 2 moles of NaOH are required to produce 1 mole of Cu(OH)2. Since we have fewer moles of CuSO4 (0.201 mol) than the 2 moles needed for the reaction, CuSO4 is the limiting reactant.

Step 3: Calculate the moles of Cu(OH)2 formed.

Since CuSO4 is the limiting reactant, it will determine the amount of Cu(OH)2 formed. According to the stoichiometry of the balanced equation, 1 mole of CuSO4 produces 1 mole of Cu(OH)2.

moles of Cu(OH)2 = moles of CuSO4 = 0.201 mol

Step 4: Calculate the mass of Cu(OH)2 formed.

Finally, we can calculate the mass of Cu(OH)2 formed using its molar mass.

Molar mass of Cu(OH)2 (copper(II) hydroxide) = 63.5 g/mol (Cu) + 2 * 16 g/mol (O) + 2 * 1 g/mol (H) = 97.5 g/mol

mass of Cu(OH)2 = moles of Cu(OH)2 * Molar mass(Cu(OH)2) = 0.201 mol * 97.5 g/mol ≈ 19.6 g

Therefore, the mass of Cu(OH)2 formed during the reaction is approximately 19.6 grams.