Solutions - Solute, Solvent, and Concentration - UNSOLVED PRACTICE SET

Q7. Define solute and solvent with one example each. In a cup of tea, identify the solute(s) and the solvent.

Q8. What is the difference between a saturated solution and an unsaturated solution? How can you convert an unsaturated solution into a saturated one?

Q9. Your mother adds 2 teaspoons of sugar to a glass of water for making lemonade. After stirring, all the sugar dissolves. Is this solution saturated or unsaturated? How would you test whether more sugar can be dissolved?

Q10. Explain why the solubility of most solids in water increases with temperature, while the solubility of gases in water decreases with temperature.

Q11. Define mass percentage of a solution. Write the formula and calculate the mass percentage when 15 g of common salt is dissolved in 135 g of water

Q12. What is meant by the term 'solubility'? State the factors on which the solubility of a solid in a liquid depends.

Q13. Explain the terms solute, solvent, and solution with examples. Describe an activity to demonstrate that the amount of solute that can dissolve in a solvent depends on temperature. Include the expected observations and conclusion.

Q14. A student is asked to prepare 250 g of a 10% mass-by-mass solution of sodium chloride. Describe the complete procedure, including the calculations, the apparatus required, and the steps to be followed. What precautions should the student take?

Q15. "Understanding concentration is essential in medicine, food preparation, and agriculture." Discuss this statement by giving two examples from each field where the concentration of solutions plays a critical role.

Q16. A chemistry teacher asks students to prepare a 15% (mass by mass) solution of sugar in water.

(a) Calculate the mass of sugar required to prepare 200 g of this solution.

(b) Calculate the mass of water needed.

(c) If a student accidentally adds 40 g of sugar to 160 g of water, what is the actual mass percentage of the solution?

(d) Is the student's solution more concentrated or less concentrated than the required 15% solution?

Q17. The solubility of potassium chloride (KCl) in water at different temperatures is given below:

(a) Plot a solubility curve using the given data.

(b) How much KCl will dissolve in 200 g of water at 40°C?

(c) A solution contains 80 g of KCl in 200 g of water at 60°C. Is it saturated or unsaturated?

(d) If this solution is cooled to 20°C, how much KCl will crystallize out?

Q18. A doctor prescribes a 0.9% (mass/volume) saline solution for a patient. The nurse has to prepare 500 mL of this solution.

(a) Calculate the mass of sodium chloride (NaCl) required.

(b) If the nurse only has a 5% (mass/volume) stock solution of NaCl, how much of this stock solution should she take and dilute to prepare 500 mL of 0.9% solution?

(c) What volume of water should be added to the stock solution?

(d) Why is it important for the nurse to prepare the exact concentration prescribed by the doctor?