Olympiad Science - Is Matter Around us Pure
Exam Duration: 45 Mins Total Questions : 30
A liquid and a solid are found together in a single phase. What is this known as?
- (a)
Solution
- (b)
Solute
- (c)
Solvent
- (d)
Emulsion
Which of the following is a homogeneous solution?
- (a)
Muddy water
- (b)
Bread
- (c)
Concrete
- (d)
A solution of sugar in water
What kind of a colloidal solution is an emulsion?
- (a)
Solid dispersed in solid.
- (b)
Liquid dispersed in liquid.
- (c)
Gas dispersed in liquid.
- (d)
Liquid dispersed in solid.
In which of the following does scattering of light takes place?
- (a)
Electrolytic solutions
- (b)
Colloidal solutions
- (c)
Electrodialysis
- (d)
Alcoholic solutions
Which of the following forms a colloidal solution in water?
- (a)
Salt
- (b)
Glucose
- (c)
Starch
- (d)
Barium nitrate
How is Brownian motion caused?
- (a)
Through temperature fluctuations within the liquid phase
- (b)
Through attraction and repulsion between the charges on the colloidal particles
- (c)
Through collision of molecules between the colloidal particles
- (d)
Through pressure variations within the liquid phase
To which of the following category does ice-cream belong?
- (a)
Solution
- (b)
Emulsion
- (c)
Element
- (d)
Suspension
What can be observed when sunlight is passed through a colloidal solution?
- (a)
Adsorption
- (b)
Coagulation
- (c)
Tyndall effect
- (d)
Brownian motion
What is a sol?
- (a)
A solid dispersed in a liquid
- (b)
A liquid dispersed in a gas
- (c)
A gas dispersed in a liquid
- (d)
A gas dispersed in a solid
In both dialysis and osmosis which particles do not pass through the semipermeable membrane?
- (a)
Water
- (b)
Small molecules
- (c)
Colloids
- (d)
All of the above
What is the name of the process for the separation of colloidal particles from those of crystalloids called?
- (a)
Dialysis
- (b)
Pyrolysis
- (c)
Peptization
- (d)
Photolysis
Shaving cream produces foam. What kind of colloid is shaving cream?
- (a)
Liquid dispersed in a gas
- (b)
Gas dispersed in a liquid
- (c)
Solid dispersed in a liquid
- (d)
Solid dispersed in a gas
What kind of solution is drinking soda?
- (a)
Gas in liquid
- (b)
Liquid in gas
- (c)
Gas in gas
- (d)
Solid in liquid
Which of the following is a true solution?
- (a)
NaC/ in sulphur dioxide.
- (b)
Copper in silver.
- (c)
Salt in petrol.
- (d)
Mud in water.
What is a solution of iodine in carbon tetrachloride called?
- (a)
Aqueous solution
- (b)
Alcoholic solution
- (c)
Non-aqueous solution
- (d)
Tincture of iodine
Which of the following is an example of a mixture?
- (a)
Sugar
- (b)
Brass
- (c)
CO2
- (d)
NO2
Which of the following obey the law of constant proportions in their formation?
- (a)
Mixtures
- (b)
Compounds
- (c)
Elements
- (d)
Colloids
How can sugar from sugar solution be separated?
- (a)
By distillation
- (b)
By evaporation
- (c)
By sublimation
- (d)
By filtration
Which of the following processes of separating substances involves both evaporation and condensation?
- (a)
Filtration
- (b)
Crystallisation
- (c)
Distillation
- (d)
Sedimentation
Which of the following processes is useful to collect pure water from a solution of sugar and water or salt and water?
- (a)
Filtration
- (b)
Evaporation
- (c)
Distillation
- (d)
Crystallisation
Which of the following processes can be useful in separating the salt from a mixture of sand and salt?
- (a)
Dissolution
- (b)
Filtration
- (c)
Evaporation
- (d)
All of the above
By which process can we separate camphor from ammonium chloride?
- (a)
Filtration
- (b)
Sublimation
- (c)
Dissolution and evaporation
- (d)
Distillation
Which of the following apparatus is used to separate a mixture of immiscible liquids?
- (a)
Centrifuge
- (b)
Condenser
- (c)
Separating funnel
- (d)
Distillation flask
Two substances P and Q when brought together, form substance R with the evolution of heat. The properties of Rare different from both P and Q. What is substance R?
- (a)
A compound
- (b)
An element
- (c)
A metal
- (d)
A mixture
Which of the following is a true solution?
- (a)
Copper in gold
- (b)
Sulphur in water
- (c)
Milk
- (d)
KC/ in sulphur dioxide
What is the smallest constituent of matter that retains its chemical identity?
- (a)
Atom
- (b)
Molecule
- (c)
Ion
- (d)
Radical
Which of the following solutions shows Tyndall effect?
- (a)
A solution of common salt
- (b)
A solution of sodium carbonate
- (c)
Starch solution
- (d)
Sugar solution
The size of a colloidal particle is
- (a)
10-1 to 10-3 cm.
- (b)
10-5 to 10-7 cm.
- (c)
10-8 to 10-5 cm.
- (d)
10-6 to 10-8 cm.
A student added 10 ml - 12 ml of Cone. H2SO4 in a test tube containing 5 g - 6 g of sugar crystals and warmed it gently. He noticed that white crystals slowly turned brown and became a black mass. What happened in this change?
- (a)
H2SO4 turned black but no change took place.
- (b)
Sugar got charred by the action of hot. cone. H2SO4 and a chemical change took place.
- (c)
It is only a physical change.
- (d)
It is an irreversible physical change.
A dispersed phase particle in a zig-zag movement is shown below.
What kind of motion is exhibited by the particle?
- (a)
Transitional motion
- (b)
Circular motion
- (c)
Linear motion
- (d)
Brownian motion
