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: Crystallisation is the process used to obtain pure copper sulphate from an impure sample.

Q2: What is a homogeneous mixture of two or more substances called?
Ans: A solution is a homogeneous mixture of two or more substances.

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

Q4: Naphthalene and sand can be separated by the process of
Ans: The separation of naphthalene from sand can be achieved through the process of sublimation.

Q5: What is an element made up of?
Ans: An element is made up of only one type of atom. For eg: Carbon (C), Iron (Fe), etc.

Q6: What type of mixture is Milk of Magnesia?
Ans: Milk of Magnesia is a suspension, not a true solution.

Q7: Give two examples of colloids from your daily life.
Ans: Milk and fog.

Q8: Name the constituents of German silver.
Ans: German silver is made of copper, zinc, and nickel.

Q9: What is the meaning of the 'concentration of a solution'?
Ans:  Concentration of a solution refers to the amount of solute dissolved in a specific amount of solvent or solution. More the solute dissolved in the solvent, more is the concentration of the solution.

Q10: Name the process used to separate liquids which have a difference in boiling points of less than 25°C.
Ans: Fractional distillation is the process used to separate liquids that have a boiling point difference of less than 25°C.

Q11: Name two categories of pure substances.
Ans: Element and compound.

Q12: Define the term Solvent.
Ans: A solvent is the component of a solution present in a larger amount that dissolves the solute.

Q13: What are two types of matter on the basis of composition?
Ans: Pure substances and mixtures are the two main types of matter based on composition.

Q14: Name the types of mixtures.
Ans: The two types of mixtures are homogeneous and heterogeneous mixtures.

Q15: Give natural examples of a mixture.
Ans: Examples of natural mixtures include seawater, mineral ores, and soil.

Q16: Name a metal that is liquid at room temperature.
Ans: Mercury is the only metal that is liquid at room temperature.

Q17: What is the principle of separation?
Ans: The principle of separation is based on differences in physical or chemical properties such as boiling point, solubility, or particle size.

Q18: Give an example of a liquid and a liquid-type solution.
Ans: Vinegar is a solution made from a mixture of acetic acid and water.

Q19: Define dispersion medium.
Ans: It is the component which is present in excess and acts as a medium in which colloidal particles are dispersed.

Q20: Define the term heterogeneous mixture.
Ans: A mixture where components are not uniformly distributed and properties vary is called heterogeneous.