Chemistry For Class IX (New Book ) - Chapter No. 6 - Solutions - Questions And Answers

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Chapter No.6- Solutions
Questions And Answers

Q.1: Define solubility. Write the name of factors affecting solubility and the general principle of solubility?
Ans: SOLUBILITY:
Solubility is defined as the maximum quantity of solute that can be dissolved in 100 grams of solvent to prepare saturated solution at a particular temperature. Different substances have different capability to dissolve in the same solvent at a particular temperature.

FACTORS EFFECTING SOLUBILITY:
1. Nature Of Solute and Solvent
2. Solute-solvent interaction
3. Temperature

GENERAL PRINCIPLE OF SOLUBILITY:

1. The general principle of solubility is "Like dissolves like'. Its mean that two substances with similar intermolecular forces are likely to be soluble in one another. It has been observed that:
   o Ionic and polar solute dissolved in polar solvents. For example, No,CO₃, sugar and alcohol are polar and dissolved in water because water is also polar.
   o Nonpolar solute dissolved in non-polar solvents. Such as oil and paints are non-polar, they are dissolved in ether as both are non-polar. Similarly, waxes and fats dissolve in benzene and not in water.
   o Nonpolar compounds are not soluble in polar solvents (water). For example, oil, petrol, benzene are non-polar, they are not dissolved in water because water is polar.
2. Solute-solvent interaction
3. Temperature

Q.2: Write down comparison of the characteristics of Solution, Suspension and Colloid.
Ans: Difference (Comparison) of the characteristics of Solution, Suspension and Colloid.

S.NO.	Solution	Suspension	Colloid
1.	Particle size less than 1	Particle size greater than 1000 nm	Particle size 1 to 100 nm
2.	Homogeneous (particles dissolve uniformly)	Heterogeneous (particles settle down after sometimes)	Homogeneous and heterogeneous (Particles do not settle down for a long time)
3.	Particles cannot be distinctly seen with the naked eye.	Particles are big enough but can be seen with naked eyes.	Colloidal particles cannot be seen with the naked eye but can be seen through ultra microscope.
4.	Clear, transparent and homogeneous.	Cloudy, but uniform and homogeneous	Cloudy, heterogeneous, at least two substances visible.
5.	Transparent but often colored.	Translucent and often opaque but can be transparent	Often opaque, but can be transparent.
6.	Cannot be separated	Cannot be separated	Can be separated easily.
7.	Do not scatter light	Scatter light, but are not transparent	Scatter light (Tyndall effect)
8.	Particles can pass through filter paper	Particles pass through filter paper.	Particles do not pass through filter paper.