WBBSE Class 9 Physical Science MCQ Questions Chapter 4.3 Solution

Well structured WBBSE Class 9 Physical Science MCQ Questions Chapter 4.3 Solution can serve as a valuable review tool before exams.

Solution Class 9 WBBSE MCQ Questions

Multiple Choice Questions :

Question 1.
Solution is a :
(i) mixture
(ii) element
(iii) compound
(iv) none of these.
Answer:
mixture.

Question 2.
The solvent of sulphur is :
(i) Water
(ii) Ethyl alcohol
(iii) Carbon disulphide
(iv) Benzene
Answer:
Carbon disulphide

Question 3.
If a saturated solution is heated :
(i) the solution becomes unsaturated.
(ii) the solution becomes super saturated.
(iii) the solution remains saturated
Answer:
The solution becomes unsaturated.

Question 4.
If more solvent is added to a saturated solution :
(i) the solution becomes super saturated
(ii) the solution becomes unsaturated
(iii) the solution remains saturated
Answer:
The solution becomes unsaturated.

Question 5.
Solubility decreases with increasing temperature :
(i) KNO₃
(ii) CaSO₄
(iii) NaCl
(iv) none of these
Answer:
CaSO₄

Question 6.
When temperature rises, solubility of gas in liquid:
(i) decreases
(ii) increases
(iii) remains unaltered
(iv) None of these
Answer:
decreases

Question 7.
If the size of the particles are 10-5 cm to 10-7 cm then the solution will be :
(i) true solution
(ii) suspension
(iii) colloid
(iv) none of these
Answer:
colloid

Question 8.
Number of water molecules present in washing soda :
(i) 5
(ii) 6
(iii) 10
(iv) 7
Answer:
10

Question 9.
Deliquescent substance is :
(i) Magnesium chloride
(ii) Washing soda
(iii) Glauber’s salt
(iv) Blue vitriol
Answer:
Magnesium chloride

Question 10.
Fog is :
(i) a solution of liquid in gas
(ii) a solution of gas in gas
(iii) a solution of solid in gas
(iv) a solution of liquid in liquid.
Answer:
a solution of liquid in gas.

Question 11.
Smoke is :
(i) a solution of gas in gas
(ii) a solution of carbon in gas
(iii) a solution of liquid in liquid
(iv) a solution of solid in solid.
Answer:
a solution of Carbon in gas.

Question 12.
Solubility remains almost unchanged with rise of temperature :
(i) NaCl
(ii) CaSO₄
(iii) Na₂ SO₄, 10 H₂O
(iv) KNO₃
Answer:
NaCl

Question 13.
Phosphorus pentoxide is :
(i) efflorescent substance
(ii) deliquescent substance
(iii) drying agent
Answer:
drying agent

Question 14.
Soluble in chloroform :
(i) sugar
(ii) common salt
(iii) oil
(iv) blue vitriol
Answer:
oil

Question 15.
lodine is soluble in :
(I) water
(ii) aicohol
(iii) acetone
Answer:
alcohol

Question 16.
Unit of concentration of solution is :
(i) g / L
(ii) g / m²
(iii) g / m
(iv) g / cm
Answer:
g / L

Question 17.
Percentage strength is :
(i) 6 g
(ii) 6 kg
(iii) 6%
(iv) 6
Answer:
6%

Question 18.
If excess amount of solute is dissolved in saturated solution then the solution is called :
(i) unsaturated solution
(ii) super saturated solution
(iii) colloid
(iv) emulsion
Answer:
super saturated solution

Question 19.
The ratio of the components of a solution is
(i) fixed
(ii) may vary
(iii) may vary to any extent
(iv) may vary within a limit
Answer:
may vary within a limit.

Question 20.
Aerated cold drinks contain CO₂, sugar and water here ; solution is of
(i) Sugar
(ii) CO₂
(iii) water
(iv) Sugar and CO₂
Answer:
Sugar and CO₂

Question 21.
Which one is true solution ?
(i) solution of common salt
(ii) solution of chalk
(iii) milk
(iv) butter
Answer:
Solution of common salt

Question 22.
Particle size of colloid is
(i) 10^-8 cm
(ii) 10^-4 cm
(iii) 10^-3 cm
(iv) 10^-5 – 10^-7cm
Answer:
10^-5 – 10^-7cm

Question 23.
Which will not diffuse ?
(i) Suspension
(ii) true solution
(iii) Coloids
(iv) none
Answer:
Suspension

Question 24.
When liquid is dispersed in solid, the product is called :
(i) gel
(ii) sol
(iii) Emulsion
(iv) foam
Answer:
gel

Question 25.
Which of the following in aqueous solution can enter into intermolecular space of water: (i) urea (ii) protein
(iii) DNA
(iv) starch
Answer:
urea

Question 26.
Solubility of which increases with increase of temperature ? :
(i) O₂
(ii) NH₃
(iii) KNO₃
(iv) SO₂
Answer:
KNO₃

Question 27.
Which of the following solutions is unstable?
(i) Saturated
(ii) Unsaturated
(iii) Super saturated
(iv) Colloidal
Answer:
Super saturated

Question 28.
Which of the following solvents is used to remove nail-polish :
(i) Ethyl alcohol
(ii) Methyl alcohol
(iii) Acctone
(iv) Terpentine oil
Answer:
Acctone

Fill in the blanks :

1. Solute + solvent = _______.
Answer:
Solution

2. A true solution is a ______ mixture.
Answer:
homogeneous

3. The solubility of KNO³ in water ________ tremendously with the rise of temperature.
Answer:
increases

4. A solution is _______ at a temperature if it can dissolve more solute or if its concentration increases.
Answer:
unsaturated

5. A solution of low solute-content is a solution.
Answer:
dilute

6. Solubility of CaSO₄ _______ with increasing temperature.
Answer:
decreases

7. A solution is saturated if it does not dissolve any more _______ at a given temperature and if its concentration remains unchanged.
Answer:
solute

8. _____ is a typical state of matter which is intermediate between true solution state and coarse suspension state of matter.
Answer:
Colloid

9. Efflorescent sustances crumble to powder when exposed to ________ due to partial or total loss of water molecules present in their crystalline structures.
Answer:
air

10. Water of crystallisation are some waster molecules which are _______ attached to the molecule of a compound as essential building components of crystals.
Answer:
chemically

11. Solubility of NaCl remains almost _______ with rise of temperature.
Answer:
unchanged

12. Water is a _____ liquid solvent.
Answer:
versatile

13. Soda water contains _______ under pressure.
Answer:
carbon dioxide

14. The particle size (diameter) of colloid lies in between _____.
Answer:
10^-5 cm to 10^-7 cm.

15. Calcium chloride is a ______ substance.
Answer:
deliquescent

16. Glauber’s salt ( Na₂ SO₄,10 H²O) is an __________ substance.
Answer:
efflorescent.

17. Crystals are homogeneous solid particles bounded by plane surfaces which meet at sharp edges and have a regular and definite _________ shapes.
Answer:
geometric.

18. Solubility of gas in liquid ________ when temperature rises.
Answer:
decreases

19. Emulsion is a colloid where small particle of one liquid are dispersed in another ________.
Answer:
liquid

20. A solution is a ________ mixture of two or more substances in solid, liquid or gaseous state.
Answer:
homogeneous.

21. Anhydrous copper sulphate is a ________ substance.
Answer:
hygroscopic

22. Unit of concentration of solution is _______.
Answer:
g/L

23. Sodium amalgam is a solution of sodium and _____.
Answer:
mercury

24. A saturated solution can be converted to an unsaturated solution by _____ the solution (Heating/Cooling).
Answer:
heating

25. Solubility of a gas in water increases by ______ pressure.
Answer:
increasing

26. Solubility of a yas at constant pressure may be increased by _______ temperature.
Answer:
decreasing

27. Sodium chloride remains in solution as _____.
Answer:
ions.

28. Rate of crystallization from saturated solution may be increased by ______.
Answer:
seeding

29. Solution is a ______ of a solute in a solvent.
Answer:
homogenous mixture.

30. Colloidal solution contains two components, ____ and ______ .
Answer:
dispersed phase/dispersed medium.

31. Milk is an example of ________ emulsion.
Answer:
oil in water

32. In case of icecream ______ acts as a emulsifier.
Answer:
gelatin

33. Ca(OH)₂ shows a ______ of solubility with the _____ of temperature.
Answer:
decrease, increase

34. _____ has no influence an the solubility of a solid ______ in a liqud solvent.
Answer:
Pressure, solute