Saturated And Unsaturated Solutions
When we dissolve a solute in a solvent, then a solution is formed. We can dissolve different amounts of solute in the same quantity of the solvent.In this way, we can get many solutions having different concentrations of the same solute. A particular solution may contain less amount of the dissolved solute whereas another solution may contain more amount of the solute in it. For example, we can prepare many salt solutions of different concentrations by dissolving different amounts of salt in the same quantity of water. So, depending upon the amount of solute present, the solutions can be classified into two groups :Unsaturated solutions and Saturated solutions. Let us discuss it in detail.
1.A solution in which more quantity of solute can be dissolved without raising its temperature,is called an unsaturated solution. For example, if in an aqueous solution of salt, more of salt can be dissolved without raising its temperature, then this salt solution will be an unsaturated solution. Actually, an unsaturated solution contains lesser amount of solute than the maximum amount of solute which can be dissolved in it at that temperature.
2.A solution in which no more solute can be dissolved at that temperature, is called a saturated solution. For example, if in an aqueous salt solution, no more salt can be dissolved at that temperature, then that salt solution will be a saturated solution. Thus, a saturated solution contains the maximum amount of solute which can be dissolved in it at that temperature. It is obvious that a saturated solution contains greater amount of solute than an unsaturated solution.
(i) A maximum of 32 grams of potassium nitrate can be dissolved in 100 grams of water at a temperature of 20°C. So, a saturated solution of potassium nitrate at 20°C contains 32 grams of potassium nitrate dissolved in 100 grams of water.
(ii) A maximum of 36 grams of sodium chloride (common salt) can be dissolved in 100 grams of water at a temperature of 20°C. So,a saturated solution of sodium chloride at 20°C contains 36 grams of sodium chloride dissolved in 100 grams of water.
In order to test whether a given solution is saturated or not, we should add some more solute to this solution and try to dissolve it by stirring (keeping the temperature constant). If more solute does not dissolve in the given solution, then it will be a saturated solution; but if more solute gets dissolved, then it will be an unsaturated solution.
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Matter in Our Surroundings - Notes
1. 3. Non-Metals are Bad Conductors of Heat and Electricity.
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3. The Case of a Liquid Solute Dissolved in a Liquid Solvent
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4. 11. Metals Usually Have a Silver or Grey Colour
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7. 7. Metals are Solids at the Room Temperature
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10. 7. Non-Metals may be Solid, Liquid or Gases at the Room Temperature.
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11. Separation Of Mixture Of a Solid And a Liquids
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12. 6. Non-Metals are Not Strong. They Have Low Tensile Strength.
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13. To Study the Properties of a Colloid
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16. To Study the Properties of a Compound of Iron and Sulphur
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18. 11. Non-Metals Have Many Different Colours.
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21. 1. Separation by a Suitable Solvent
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25. 6. Metals are Usually Strong. They Have High Tensile Strength.
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27. To Study the Properties of a Solution
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30. Separation of Mixture Of Two Solids
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36. To Distinguish a Colloid from a Solution
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38. 3. Metals are Good Conductors of Heat and Electricity.
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44. 1. Separation by Fractional Distillation
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47. Solutions, Suspensions And Colloids
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49. Chemical Formula for daily use material
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50. To Separate the Salt-Water Mixture (or Salt-Solution)
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