Tag: mix and separate

Questions Related to mix and separate

Which of the following methods is most suitable for obtaining a pure, dry sample of sodium chloride from a mixture of solid sodium chloride and sand?

  1. Shake the mixture with water, filter and dry the residue on the filter paper.

  2. Shake the mixture with water, filter and evaporate the filtrate.

  3. Heat the mixture gently and collect the substance which sublimes

  4. Heat the mixture gently and collect the substance which boils off


Correct Option: B
Explanation:

To obtain dry sample of NaCl from sand, first we have to dissolve it in water;

then, NaCl gets dissolved into water and by filtration we can separate sand particles and after evaporation of water we get dry sample of NaCl.

A mixture of ____________ can be separated by magnetic attraction.

  1. iron and steel

  2. copper and steel

  3. copper and tin

  4. sand and tn


Correct Option: D
Explanation:
A mixture of sand and tin can be separated by magnetic attraction.
Sand is magnetic and tin is non magnetic. For the mixture to be separated by magnetic attraction, one component should be magnetic whereas remaining components should be non magnetic.

The process in which magnetically susceptible material is extracted from a mixture using a magnetic force is called:

  1. ferromagnetic separation

  2. magnetic separation

  3. crystallisation

  4. diamagnetic separation


Correct Option: B
Explanation:

Magnetic separation is a process in which magnetically susceptible material is extracted from a mixture using a magnetic force. This separation technique can be useful in mining iron as it is attracted to a magnet.

The essential condition for winnowing activity is:

  1. water

  2. wind

  3. electricity

  4. machines


Correct Option: B
Explanation:

Winnowing is a method of separation of chaff or husk from wheat/grains. Also called the process of separation of heavier components from lighter components by the application of wind.

In which of the following mixtures hand picking method can be best used?

  1. The mixture of gas and liquid.

  2. The mixture of liquid and liquid.

  3. The mixture of solid and liquid.

  4. The mixture of solid and solid.


Correct Option: D
Explanation:

Hand picking is a method of separation used where one of the component is in small quantity. And it is best for mixture of solids, for eg- Stone in rice.

What are the advantages of handpicking methods?

  1. The materials which are very small can be removed by handpicking method.

  2. The materials which can not removed by machines, can be easily removed by handpicking.

  3. This method take less time for less quantity of substance.

  4. All of these


Correct Option: D
Explanation:

Advantages of Handpicking Method:-

$\longrightarrow$ Useful and also less time consuming for separating small quantity of mixture.
$\longrightarrow$ This method does not need any special machine.
$\longrightarrow$ Efficiency of using this method is higher than others.

How can husk particles be separated from pulses?

  1. By hand picking

  2. By winnowing

  3. By churning

  4. By hydraulic washing


Correct Option: B
Explanation:

Winnowing- Winnowing is a method of separation of chaff or husk from wheat/grains. Also called process of separation of heavier components from lighter components by the application of wind.

Hold the container of pulses in the direction of the wind and then shake, pulses being heavier will fall straight down and husks being lighter will fall away due to the wind.

The freezing point of pure water is ____________.

  1. 100 degree centigrade

  2. 50 degree centigrade

  3. 20 degree centigrade

  4. zero degree centigrade


Correct Option: D
Explanation:

Freezing point is the temperature where a liquid converts into solid. Water converts into ice at zero degrees centigrade. So degree zero centigrade is the freezing point of water. Hence option $D$ is correct.

Sieving is the method used to saperate the particles of

  1. same size

  2. different size

  3. same color

  4. different colour


Correct Option: B
Explanation:

If the size of particle it too small to be picked by hand,sieving is used for separating substances. A sieve; having pores of certain  size is used. The bigger particles are retained by the sieve whereas the smaller particle are passed  through it. For example; this method is used for separating bran from flour, sand from gravel, pearls of different sizes,etc.

Threshing is used for separating

  1. two same size particles

  2. same color particles

  3. different color particles

  4. seeds from harvesting stalks


Correct Option: D
Explanation:

Threshing is used for separating seeds from the harvested stalks.

This can be done by either beating the stalks or by using machines.