Important Questions with solution

Q1: What is mixture? Give some examples.

Ans: Things that are made of two or more than two substances are known as mixture. Examples – air, dust particles, Sherbet etc; 

Q2: Define Separation.

Ans:  By various methods a mixture is separated into its components is known as separation.

Q3: What is Sedimentation?

Ans: The settling down of heavy solid particles from the liquid in a mixture of solid and liquid substances is known as sedimentation.

Q4: What is decantation?

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

Q5:  What is filtration?

Ans:  It is a method of separating specific particles from a liquid mixture by passing it through a porous membrane.

Q6:  What is sublimation?

Ans: Direct conversion of a solid into gas or gas into a solid, this process of conversion is called sublimation.

Q7: Some solid substances have property to covert directly into vapour on heating without being converted back into a liquid.

1. What is called this process?
2.  Name some such substances.
3. What happens when cooled the vapour?

Ans:      

1. This process is called sublimation.
2. Ammonium Chloride, Camphor, Naphthalene etc;
3. when cooled the vapour it gets converted directly into a solid.

Q8:  What is evaporation? What is its used ?

Ans: Conversion of water into water vapour is known as evaporation. It is used for separating salty or water soluble substances from water. Such as salt from sea.

Q9:  How will you separate salt from a mixture of Ammonium Chloride?

Ans: The method sublimation will be used for separating salt from a mixture of Ammonium Chloride. On heating Ammonium Chloride gets converted directly into vapour, and salt remains in the pot. 

Q10:  How can straw be separated from wheat grains?

Ans: Winnowing.

Q11:  How can a mixture of sand and marble chips be separated?

Ans:  Sieving.

Q12:  How can clean water be separated from muddy water?

Ans:  Sedimentation and loading.

Q13: There is given a mixture of wood powder, iron nails, sand, and iron fillings. Which process of separation would you use to separate the iron things?

Ans:  Magnetic separation

Q14: What type of substances can be separated by sieves/ sieving method?

Ans: Substances of two solids of different size can be separated by sieves/ sieving method like flour.