Study Materials

NCERT Solutions for Class 9th Science

 

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Chapter 2. Is Matter around us Pure

Additional -Questions

 

 

 

Additional -Questions

Que: - What is solution?

Ans: - A solution is a homogeneous mixture of two or more substances. Ex. – lemonade and soda water etc.

Que:- What  is mixture ?

Ans:- A mixture is a combination of two or more substances which show the properties of each of the substance combined. A mixture of iron powder and sulphur show the properties of both sulphur and iron.

Que: - write the type of mixture? Difined them ?

Ans: -

  1. Homogenous mixtureMixture having uniform composition are called homogeneous mixture.
  2. Heterogeneous mixture - – those mixture that do not have uniform composition are called heterogeneous mixture

Que: - Write the type of solution?

Ans: -  There are three type :-

  1. Colloidal solution
  2. Concentration solution
  3. Suspension

Que: - What is suspension?

Ans: - suspension is a heterogeneous mixture which solids are dispersed in liquids are called suspension.

Que: - What is solute?

Ans: - The component of the solution that is dissolved in the solvent (usually present in lesser quantity) is called

the solute.

Que: - Write the properties of a solution?

Ans: - Properties of a solution

  1. A solution is a homogeneous mixture.
  2. The particles of a solution are smaller than 1 nm.
  3. They cannot be seen by naked eyes.
  4. They do not scatter a beam of light passing through the solution.
  5. The path of light is not visible in a solution.
  6. The solute particles cannot be separated from the mixture by the process of filtration.

 

Que : - Write the properties of suspension.

Ans : - The properties of suspension.

  1. Suspension is a heterogeneous mixture.
  2. The particles of a suspension can be seen by the naked eye.
  3. The particles of a suspension scatter a beam of light passing through it and make its path visible.
  4. They can be separated from the mixture by the process of filtration.

Que:-  Write the properties of a colloid ?

Ans: -  The properties of a colloid

  1. A colloid is a heterogeneous mixture.
  2. The size of particles of a colloid is too small to be individually seen by naked eyes.
  3. Colloids are big enough to scatter a beam of light passing through it and make its path visible.
  4. They do not settle down when left undisturbed, that is, a colloid is quite stable.

Que : - What is solubility?

Ans;  - The amount of the solute present in the saturated solution at this temperature is called its solubility.

Que:  - Write the type of solution? Define them ?

Ans: -

  1. Saturated solution –  When no more solute can be dissolved in a solution at a given temperature, it is called a saturated solution.
  2. Unsaturated solution – The amount of solute contained in a solution is less than the saturation level, it is called an unsaturated solution.

Que: - What is solvent ?

Ans;- The component of the solution that dissolves the other component in it (usually the component present in larger amount) is called the solvent.

Que: What is decantation?

Ans:      The process of separating a solid from a liquid by pouring out the liquid is known as decantation.

Que:- What is dilute ?

Ans:- Depending upon the amount of solute present in a solution, it can be called a dilute.

Que: - How can we separate cream from milk?

Ans: - By the centrifugation.

Que; - What is chromatography?

Ans: - This process of separation of components of a mixture is known as chromatography.

Que: - What is chemical change ?

Ans:- Chemical change brings change in the chemical properties of matter and we get new substances. A chemical change is also called a chemical reaction.

Que:- How can we separate mixture of two imscible liquid?

Ans:-By distillation.

Que:- How can we separate a mixture of salt and ammonium chcoride?

Ans:- By susblimation

Que:-What is crystallization?

Ans:- Crystallisation is a process that separates a pure solid in the form of its crystals from a solution.

Que:- Write the difference between  a pure substance and a mixture?

Ans: -

 

Que:-What are the types of pure substance?

Ans; -  There are two types :-

  1. Element
  2. Compound

Que: What is element?

Ans: An element is a pure substances of matter. Which can’t be broken down into simpler substances by chemical method.

Ex. -  copper, Iron, Alumunium, Oxygen, nitrogen etc.

Que: Write the types of element and define them ?

Ans:  Element can be normally divided into metal non-metal and metalloids.

1. Metal:-

2. Non metal -

3. Metalloids:- some elements have intermediate properties between those of metals and non-metals they are called metalloids examples: are boron, silicon germanium etc.

Que: Write the properties of metal and non-metal? 

 Ans: Metals usually show some or all of the following properties:

 metal-

• They have a lustre (shine).

• They have silvery-grey or golden-yellow colour.

• They conduct heat and electricity.

• They are ductile (can be drawn into wires).

• They are malleable (can be hammered into thin sheets).

• They are sonorous (make a ringingsound when hit).

  Non metal:-

 Non-metals usually show some or all of the following properties:

• They display a variety of colours.

• They are poor conductors of heat and electricity.

• They are not lustrous, sonorous or malleable.

Que- What is compound?

Ans- A compound is a substance composed of two or more elements, chemically combined with one another in a fixed proportion.

 

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