15 extra multiple-choice questions for Solutions (10th Standard Science, Samacheer Kalvi), beyond the ones printed in the textbook — each with the correct option highlighted and a clear, worked explanation. Free to read in English and Tamil.
Q1
A solution prepared by dissolving salt and sugar in water is an example of a ternary solution. How many solutes and solvents are present in this solution?
- A. Two solutes and one solventCorrect
- B. One solute and two solvents
- C. Three solutes and one solvent
- D. One solute and one solvent
Explanation. A ternary solution contains three components. In this case, there are two solutes (salt and sugar) and one solvent (water) that make up the three components.
Q2
Which of the following is an example of a liquid solute dissolved in a solid solvent?
- A. Copper dissolved in gold
- B. Mercury mixed with sodiumCorrect
- C. Water vapour in air
- D. Carbon dioxide dissolved in water
Explanation. Mercury is a liquid metal (solute) and sodium is a solid metal (solvent), forming an amalgam which is a liquid in solid solution.
Q3
What is the solubility of glucose in water at 25°C?
- A. 36 g/100 g water
- B. 80 g/100 g water
- C. 91 g/100 g waterCorrect
- D. 184 g/100 g water
Explanation. According to the textbook table of solubilities at 25°C, the solubility of glucose in water is 91 g per 100 g of water.
Q4
Which of the following pairs represents a solute and a non-aqueous solvent?
- A. Sodium chloride and water
- B. Glucose and water
- C. Sulphur and carbon disulphideCorrect
- D. Copper sulphate and water
Explanation. A non-aqueous solution has a solvent other than water. Sulphur dissolves in carbon disulphide, which is a non-aqueous solvent.
Q5
In which of the following processes does the solubility of the solid solute decrease as the temperature of the solution is increased?
- A. Endothermic process
- B. Exothermic processCorrect
- C. Isothermal process
- D. Adiabatic process
Explanation. In an exothermic process, heat is released during dissolution, so increasing temperature decreases solubility according to Le Chatelier's principle.
Q6
Why do aquatic animals thrive more in cold regions than in warm regions?
- A. Solubility of oxygen is higher at lower temperaturesCorrect
- B. Solubility of carbon dioxide is lower at lower temperatures
- C. Cold water prevents the growth of harmful bacteria
- D. Water density is higher in cold regions
Explanation. The solubility of gases like oxygen in liquid decreases with an increase in temperature. Therefore, cold water contains more dissolved oxygen, aiding aquatic life.
Q7
Which law states that the solubility of a gas in a liquid is directly proportional to the pressure of the gas over the solution at a constant temperature?
- A. Boyle's Law
- B. Henry's LawCorrect
- C. Charles's Law
- D. Avogadro's Law
Explanation. Henry's law governs the effect of pressure on gas solubility in a liquid, stating that solubility is directly proportional to the pressure of the gas.
Q8
Why does the volume percentage of a liquid-in-liquid solution decrease when the temperature is increased?
- A. Liquid solutes evaporate rapidly
- B. Liquids expand with an increase in temperatureCorrect
- C. Dissolution of liquids is always exothermic
- D. Solute molecules undergo decomposition
Explanation. Volume percentage is temperature-dependent because liquids expand when heated, changing the total volume of the solution.
Q9
In commercial products, the concentration of active ingredients in ointments and soaps is typically expressed in which format?
- A. Volume / Volume percentage (v/v)
- B. Mass / Mass percentage (w/w)Correct
- C. Mass / Volume percentage (w/v)
- D. Volume / Mass percentage (v/w)
Explanation. As mentioned in the textbook, the concentration of ingredients in ointments, antacids, and soaps is conventionally expressed as w/w (weight/weight or mass percentage).
Q10
What is the chemical formula and IUPAC name of Green Vitriol?
- A. FeSO4 . 7H2O (Iron(II) sulphate heptahydrate)Correct
- B. CuSO4 . 5H2O (Copper(II) sulphate pentahydrate)
- C. MgSO4 . 7H2O (Magnesium sulphate heptahydrate)
- D. ZnSO4 . 7H2O (Zinc sulphate heptahydrate)
Explanation. Green vitriol is hydrated iron(II) sulphate with seven molecules of water of crystallization, denoted as FeSO4 . 7H2O.
Q11
When blue coloured copper sulphate pentahydrate crystals are heated, they turn white. This change in colour is due to the loss of:
- A. Sulphate ions
- B. Copper ions
- C. Water of crystallizationCorrect
- D. Oxygen gas
Explanation. Heating hydrated copper sulphate drives off its water of crystallization, transforming the blue crystalline salt into white anhydrous copper sulphate.
Q12
Deliquescence is most likely to occur under which of the following environmental conditions?
- A. High temperature and dry atmosphere
- B. Low temperature and humid atmosphereCorrect
- C. High temperature and humid atmosphere
- D. Low temperature and dry atmosphere
Explanation. According to the textbook, deliquescence occurs when the temperature is low and the atmosphere is humid, which allows the salt to absorb enough water to dissolve.
Q13
Which of the following is a deliquescent substance, rather than a hygroscopic substance?
- A. Concentrated Sulphuric acid (H2SO4)
- B. Phosphorus pentoxide (P2O5)
- C. Silica gel
- D. Caustic soda (NaOH)Correct
Explanation. Conc. H2SO4, P2O5, and silica gel are hygroscopic (absorb moisture without dissolving). Caustic soda (NaOH) is deliquescent as it dissolves in the absorbed moisture.
Q14
If 1.5 g of a solute is dissolved in 15 g of water to form a saturated solution at 298 K, what is the solubility of the solute at this temperature?
- A. 1.0 g
- B. 10 gCorrect
- C. 15 g
- D. 100 g
Explanation. Solubility is calculated as (Mass of solute / Mass of solvent) * 100. Here, (1.5 / 15) * 100 = 10 g per 100 g of water.
Q15
A solution is prepared by dissolving 45 g of sugar in 180 g of water. Calculate the mass percentage of the solute in this solution.
- A. 20%Correct
- B. 25%
- C. 22.2%
- D. 15%
Explanation. Mass percentage = (Mass of solute / (Mass of solute + Mass of solvent)) * 100. Thus, (45 / (45 + 180)) * 100 = (45 / 225) * 100 = 20%.
Frequently asked questions
How many MCQs are there in Solutions?
This chapter has 15 book-back multiple-choice questions, each with the correct answer and a step-by-step explanation.
Are these 10th Standard Science MCQs free to practise online?
Yes. Every question, answer and explanation here is free, and you can also take them as a timed practice test.
Where can I find the Solutions book-back answers?
The correct option for each question is highlighted on this page with a worked explanation, plus a quick answer-key summary at the top.
