Saturday, May 12, 2012

NCERT_CBSE 6th Science : Separation of Substances merit gain study help

Q. What is supernatant liquid ?

Ans: A clear liquid that collected by decantation is called supernatant liquid.
Q. Define loading.

Ans : The process of increasing the rate of sedimentation ion by adding potash alum (fitkiri)  to it is called loading.Sometimes very fine solid particles do not sink to the bottom during sedimentation.By adding potash alum impurities became heavier and settle down .eg. muddy water, cleaning of river water .
Q. What is Filtration?

Ans: Filtration is a separation technique that is used to separate a solid that has not dissolved in a liquid.In this process mixture of the solid and liquid is allow to pass  through the filter paper.The clear liquid separated in the container is called the filtrate. The solid that remains in the filter paper is called the residue.

Q. Why filtration is preferred over decantation?

Ans:  Sometimes in decantation the liquid is not completely separated from an insoluble liquid then we  apply  the method of decantation.

Q. Why do we employ the method of loading sometimes after sedimentation and  decantation?

Ans. Loading helps sedimentation. Sometimes very fine solid particles do not sink to the bottom, they remain suspended in water so these fine particles can be separated from loading.

Q.  Q.  What do you mean by method of evaporation?

Ans: The process of changing water into water vapor is called evaporation.  The process of removing water or moisture from a mixture either by heating or by direct sunlight is called evaporation, e.g., salt from sea water is obtained by this method.

Q. what is condensation?

Ans: Conversion of water vapour into liquid on cooling is called condensation.

Q. How can you separate a mixture of salt & sand?

Ans. we add the given mixture in water and left undisturbed for some time.  sand particles settle down at bottom and  salt get dissolved in water . we apply the method of filtration or decantation to obtain salt water solution.  After that s evaporate salt solution and we obtain salt.
Q. What is magnetic separation?
Ans. The process of separating a magnetic substance from a non-magnetic substance, by using a magnet is called magnetic separation. For example, impurities of iron.  

Q. How will you separate a mixture of iron fillings and sulphur ?

Ans:  A mixture of iron fillings and sulphur can be separated by magnetic separation. We take a magnet and move it through the mixture till the whole of iron fillings are attracted by the magnet. Remove the iron fillings from the magnet and keep them separately. Sulphur powder is left beind on the sheet of paper.

Q. How will you separate a mixture of iron filings, sand and common salt ?

Ans We take a magnet and move it through the mixture till the whole of iron fillings are attracted by the magnet . Now dissolve the mixture in 100 ml of water. Filter the mixture. The sand is left on the filter paper, and the clear common salt solution collects as a filtrate.  Now,  we heat salt solution. In a few minutes, water evaporates, leaving behind dry common salt.

Also like to read

6th Science : Cleaning of food or Separation solved question           Read and Download
Separation of Substances merit gain Solved questions                     Read ad Download
CBSE 6th Science : Separation of Substances solution                   Read and Download
6th Science : Separation of Substances Hots question                    Read and Download

No comments:

Post a Comment