Mixture

Q1. What is mixture? List the ways to separate the mixture.

Ans:

A mixture is a substance in which two or more than two pure substances are mixed in any proportion. They do not undergo a chemical change but simply remain together and retain their individuality.

The ways to separate the mixture are listed below:

1. Centrifugation
2. Chromatography
3. Filteration
4. Distillation
5. Seiving
6. Sedimentation and decantation, etc.

Q2. Define homogeneous mixture and heterogeneous mixture with examples.

Ans:

Homogeneous mixture: A mixture in which particles of component of the mixture are uniformly distributed is called homogeneous mixture. For example: sugar solution, salt solution etc.

Heterogeneous Mixture: A mixture in which the particles of the components of the mixture are not distributed uniformly is called heterogeneous mixture. For example: sand and water, kerosene and water etc. 

Q3. Define the following terms:

1. Centrifuging:
Ans: It is a method of separation of heavier and lighter objects by rotating the mixture kept in a vessel at high speed.
2. Chromatography:
Ans:Chromatography is a technique that is used for separating the components of a mixture by passing it through a column or sheet of an absorbing material.
3. Crystallization:
Ans:The process in which separation of mixtures take place by crystals formation is called crystallization.
4. Solution:
Ans: Solution is a homogeneous mixture of solute and solvent.
5. Solute:
Ans: Solute is a component of solution which gets dissolved in solvent.
6. Solvent:
Ans: Solvent is a component of solution which disolve solute.
7. Saturated Solution:
Ans: A solution which is unable to dissolve more solute at a given temperature is called saturated solution.
8. Unsaturated Solution:
Ans: A solution which can dissolve more solute at a given temperature is called unsaturated solution.

Q4. Which method is used for separating cream from milk?

Ans:

Centrifugation method is used for separating cream from milk. 

Q5. What kind of mixture is separated by using centrifugation method?

Ans:

The mixture of lighter and heavier particles are separated by centrifugation method. 

Q6. One should know the properties of the constituents of a mixture to separate the mixture. Why? Explain with example.

Ans:

Different components or matters are present in mixture in different forms and different ratio. Some of these substances are soluble in water where as some are insoluble. Similarly, some of them possess magnetic properties. Therefore, it is very difficult to separate them in the lack of knowledge of the particular properties. For example: Form the mixture of alcohol and water, alcohol can't be separated by simple technique. Distillation process can be used to separate the alcohol from the mixture of alcohol and water. So, it is necessary to have the knowledge about the properties of the components of mixture to separate its components. 

Q7. What is distillation?

Ans:

When liquid is heated then it changes into vapour. Thus formed vapour os cooled to get liquid. This proces is called distillation.

Q8. Write some uses of distillation process.

Ans:

The uses of distillation process are as follows:

1. The distilled water is used in battery or inverter.
2. The people of arabic coun try uses this method to get drinking water from sea water.

Q9. What is meant by fractional distillation?

Ans:

The process of separating the mixture of components according to the boiling point by the method of distillation is called fractional distillation. 

Q10. What type of mixture is separated by fractional distillation?

Ans:

The mixture of liquid having different boiling points are used to separate by fractional distillation. 

Q11. Fractional distillation method is not used to separate the mixture of liquids having same boiling point. Why?

Ans:

If the different liquids have same boiling point then while heating they evaportate at a time and after cooling they form the same mixture. So, we cannot separate the mixture of liquid having same boiling points by fractional distillation. 

Q12. How is mixture of water and kerosene separated?

Ans:

The mixture of water and kerosene is separated by fractional distillation.

Q13. What is the use of fractional distillation?

Ans:

The main use of fractional distillation is to separate diesel, petrol, kerosene, etc from crude mineral oil.

Q14. What type of mixture is separated by chromatography?

Ans:

The mixture of various colours can be separated by chromatography. 

Q15. Write any three uses of chromatography.

Ans:

The following are the three uses of chromatography:

1. To separate the medicines contain in urine or blood.
2. To separate colour pigments from the mixture.
3. To separate the colour from the mixture of natural or artificial coloured materials.

Q16. What is crystral? How are crystals made?

Ans:

Crystal is a solid substance bounded by plane faces meeting in sharp edges and having geometrical shape.

Crystals can be prepared by following methods:

1. By cooling the saturated solution.
2. By cooling the liquified solid.
3. By sublimation method.

Q17. What should be done to develop big crystal? Or, How can you obtain big crystal?

Ans:

The hot staurated solution of a solute or solid substance should be cooled down slowly at ordinary temperature to develop the big crystal of a solute. 

Q18. Which method do you use to separate pure salt from rock salt?

Ans:

Crystallization process can be used to separate pure salt from the saturated solution of rock salt. This is because the impurities present in rock salt will be left behind in the water and pure crystal can be separated. 

Q19. Match the following:

Ans:

Group A	Group B
Sand and water	Filtration
Iodine and salt	Sublimation
Alcohol and water	Distillation
Red ink and blue ink	Chromatography
Cream and milk	Centrifuging
Crystals of common salt	Cubic
Mixture	Sand and water
Crystals of alum	Rhombic
Crystal of copper sulphate	Octahedral