Page 72 - 6273

CONTROL TASKS

1.200 g of water 11.2 g of potassium hydroxide is dissolved. The density of the

3
resulting solution is 1.04 g/cm . Calculate the molar concentration of this solution.
3
2. How many grams of magnesium sulfate is needed to prepare 200 cm of a 0.2 M
solution?

3. Calculate the molar concentration of the solution, 650 cm3 of which contains 5.6

g of potassium hydroxide.

3
4. What is the mass of HNO 3 in 2 dm of its 0.1M solution?
5. Calculate the molar concentration of the sulfate acid solution if its mass fraction

3
44%, and density is 1.34 g/cm .
6. Calculate the mass of potassium chloride necessary to prepare a solution of 300

3
cm with the molar concentration of 0.15 M.
3
7. The density of 26% KOH solution is 1.24 g/cm . Calculate the molar
concentration of the solution.

8. How much water should be added to 500 g of 25% solution to get 10% solution?
9. Calculate the pH of a 0.1 M solution of HCl, considering that it is completely

dissociated.
10. Calculate the pH of a 0.1 M solution of NaOH, considering that it is completely

dissociated.

11. Which of these salts hydrolyse

AlCl 3, (NH 4) 2CO 3, K 2SO 3, NaClO 4?

Make up for them molecular, full, and shortened ionic equations of hydrolysis.

For each case, indicate the reaction of the medium (acidic, alkaline, approximately

neutral) and its pH (more than, less than, or equal to 7).

72