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.
- What is called this process?
- Name some such substances.
- What happens when cooled the vapour?
Ans:
- This process is called sublimation.
- Ammonium Chloride, Camphor, Naphthalene etc;
- 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.