Class 9 Science Chapter 2 Question Answers - Is Matter Around Us Pure?

Q1: Name the process by which pure copper sulphate can be obtained from its impure sample.
Ans: Crystallization.

Q2: A homogeneous mixture of two or more substances called
Ans: Solution.

Q3: The component of the solution that is present in a smaller proportion
Ans: Solute.

Q4: A system which has the same properties throughout is called
Ans: Homogeneous.

Q5: Naphthalene and sand can be separated by the process of
Ans: Sublimation.

Q6: An element made up of only one type of—
Ans: Atom.

Q7: Milk of Magnesia is a-
Ans: True solution.

Q8: Name the process by which all dyes present in black ink can be recovered.
Ans: Chromatography.

Q9: A colloid which has liquid as the dispersed phase and solid as the dispersion medium called
Ans: Gel.

Q10: Write the name of any two compounds that sublime on heating.
Ans: Ammonium chloride and iodine.

Q11: Give two examples of colloids from your daily life.
Ans: Milk and fog.

Q12: Name the constituents of German silver.
Ans: Copper and zinc.

Q13: What is the meaning of the 'concentration of a solution'?
Ans: The relative amount of solute and solvent present in a given quantity of the solution is known as the concentration of a solution.

Q14: Name the process used to separate liquids which have a difference in boiling points of less than 25°C.
Ans: Fractional distillation.

Q15: Name two categories of pure substances.
Ans: Element and compound.

Q16: Define the term Solvent.
Ans: Component of the solution that is present in a larger proportion and dissolves the other substance is called the Solvent.

Q17: What are two types of matter on the basis of composition?
Ans: Pure substance and mixture.

Q18: Name the types of mixtures.
Ans: Homogeneous mixture and heterogeneous mixture.

Q19: Give natural examples of a mixture.
Ans: Sea water, minerals, soil.

Q20: Name a metal that is liquid at room temperature.
Ans: Mercury.

Q21: What is the principle of separation?
Ans: The difference in physical or chemical properties of components of the mixture is the basis of separation.

Q22: Give an example of a liquid and liquid-type solution.
Ans: Vinegar is a mixture of acetic acid and water.

Q23: Define dispersion medium.
Ans: It is the component which is present in excess and acts as a medium in which colloidal particles are dispersed.

Q24: Define the term heterogeneous.
Ans: A substance that does not have the same properties throughout the mixture is called heterogeneous.

Q25: Define Chromatography.
Ans: The process of separation of different dissolved constituents of a mixture by absorbing them over an appropriate absorber is called chromatography.