Question

Cмешаем 400г 20%-ого раствора NaOH с 300г 30%-ого раствором AlCl3. Найти молярную массу.

Answer 1

Есть два возможных уравнения реакции:
1) 3NaOH + AlCl3 --> Al(OH)3 + 3NaCl (3:1)
2) 4NaOH + AlCl3 --> Na[Al(OH)4] + 3NaCl (4:1)

n(NaOH)= 400*0.2/(23+16+1)= 2 моль
n(AlCl3)= 300*0.3/(27+35.5*3)= 0.67 моль
n(NaOH):n(AlCl3)= 2:0.67= 3:1 ==> 1)
Моляная масса продукта Al(OH)3 = 27+ (16+1)*3= 78

Answer 2

Calculating Molar Mass after Mixing NaOH and AlCl3 Solutions

To find the molar mass after mixing 400g of 20% NaOH solution with 300g of 30% AlCl3 solution, we can use the formula:

Molar mass = (mass of solute / molarity) * 1000

First, let's calculate the molar mass of NaOH and AlCl3 separately.

1. Molar Mass of NaOH: - The molar mass of NaOH is approximately 40 g/mol.

2. Molar Mass of AlCl3: - The molar mass of AlCl3 is approximately 133.34 g/mol.

Now, let's calculate the molarity of the solutions.

3. Molarity of NaOH Solution: - Molarity = (mass of solute / molar mass of NaOH) * (1000 / volume of solution in liters) - Molarity = (400 / 40) * (1000 / 200) = 10 mol/L

4. Molarity of AlCl3 Solution: - Molarity = (mass of solute / molar mass of AlCl3) * (1000 / volume of solution in liters) - Molarity = (300 / 133.34) * (1000 / 300) = 6.25 mol/L

Now, we can find the molar mass after mixing the solutions.

5. Molar Mass after Mixing: - Molar mass = (total mass of solute / total molarity) * 1000 - Total mass of solute = 400g (NaOH) + 300g (AlCl3) = 700g - Total molarity = 10 mol/L (NaOH) + 6.25 mol/L (AlCl3) = 16.25 mol/L - Molar mass = (700 / 16.25) * 1000 ≈ 43.08 g/mol

Therefore, the molar mass after mixing the solutions is approximately 43.08 g/mol.