Class 9 Chemistry Chapter 6 Question Answer
Important Notes of Class 9 Chemistry Chapter 6 Question Answer English Medium written by Professor M. Shahid Suib. These notes are very helpful in the preparation of Solutions Class 9 for students of the Class 9 Chemistry Chapter 6 Question Answer English Medium and these are according to the paper patterns of all Punjab boards.
Summary and Contents:
Topics which are discussed in the notes are given below:
- Complete Exercise MCQs of Chapter No.6: Solutions
- Complete Exercise Short Questions with Answers of Chapter No.6: Solutions
- Why the suspensions does not form a homogeneous mixture.
- Why we stir paints thoroughly before using?
- What do you mean by, like dissolves like? Explain with examples.
OR
What is general principle of solubility?
- Why is iodine soluble in CCl4 and not in water?
- Why test tube become cold when KNO3 is dissolved in water?
- Why are the colloids quite stable?
- Why does the colloid show Tyndall effect?
- What is the Tyndall effect and on what factors it depends?
- Define Molarity. Write its formula.
- Define solubility.
- What is meant by aqueous solution? Give an example.
- Define solute and solvent.
- Define aqueous solution.
- Define saturated solution.
- Define supersaturated solution.
- Define unsaturated solution.
- What is the difference between dilute and concentrated solution?
- Long Questions:
- Define solubility and what is the general principle of solubility? Explain.
- What is the difference among the following? (i) solution (ii) colloids (iii) suspensions
- Describe the solute-solvent interaction for the preparation of the solution.
- What is the solubility? How temperature effect it. Write in detail.
- SOLUBILITY: Solubility is defined as the number of grams of the solute dissolved in 100 g of a solvent to prepare a saturated solution at a particular temperature. The concentration of a saturated solution is referred to as solubility of the solute in a given solvent. Following are the factors which affect the solubility of solutes:
- 1. The general principle of solubility is, like dissolves like.
- i. The ionic and polar substances are soluble in polar solvents. Ionic solids and polar covalent compounds are soluble in water e.g., KC1, Na2CO3, CuSO , sugar, and alcohol are all soluble in water.
- ii. Non-polar substances are not soluble in polar solvents. Non-polar covalent compounds are not soluble in water such as ether, benzene, and petrol are insoluble in water.
- iii. Non-polar covalent substances are soluble in non-polar solvents (mostly organic solvents). Grease, paints, naphthalene are soluble in ether or carbon tetrachloride etc.
- Solubility and Solute-solvent interaction: The solute-solvent interaction can be explained in terms of creation of attractive forces between the particles of solute and those of solvent. To dissolve one substance (solute) in another substance (solvent) following three events must occur:
- i. Solute particles must separate from each other
- ii. Solvent particles must separate to provide space for solute particles.
- iii.Solute and solvent particles must attract and mix up.
- Solution formation depends upon the relative strength of attractive forces
between solute-solute, solvent-solvent and solute-solvent. Generally solutes are solids.
Ionic solids are arranged in such a regular pattern that the inter-ionic forces are at a
maximum. If the new forces between solute and solvent particles overcome the solutesolute attractive forces, then solute dissolves and makes a solution. If forces between
solute particles are strong enough than solute-solvent forces, solute remains insoluble
and solution is not formed. Dissolution process by the interaction of
solvent molecules with the solute ions. The solvent molecules first pull apart the solute
ions and then surround them. In
this way, solute dissolves and
solution forms.
- Effect of Temperature on solubility: Temperature has major effect on the solubility of most of the substances.
Generally, it seems that solubility increases with the increase of temperature, but it is
not always true. When a solution is formed by adding a salt in solvent, there are different possibilities with reference to effect of temperature on solubility. These possibilities are discussed here.