Extra questions
1. Define sieving
2. Draw and explain sedimentation, decantation and filteration
3. Define evaporation and condensation
4. How is salt collected from sea water?
5. Define saturated solution
6. Explain the method to separate the mixture of sand and salt?
Answers
1.Sieving. Sieving is a simple technique for separating particles of different sizes. A sieve such as used for sifting flour has very small holes. Coarse particles are separated or broken up by grinding against one another and the screen openings. ... Sieves are also used to separate stones from sand.
3.Condensation is the change from a vapor to a condensed state (solid or liquid). Evaporation is the change of a liquid to a gas.
4.Salt is harvested through solar evaporation from seawater or salt lakes. Wind and the sun evaporate the water from shallow pools, leaving the salt behind. It is usually harvested once a year when the salt reaches a specific thickness. After harvest, the salt is washed, drained, cleaned and refined.
5.The term saturated solution is used in chemistry to define a solution in which no more solute can be dissolved in the solvent. It is understood that saturation of the solution has been achieved when any additional substance that is added results in a solid precipitate or is let off as a gas.
6.Separating Sand and Salt
Probably the easiest method to separate the two substances is to dissolve salt in water, pour the liquid away from the sand, and then evaporate the water to recover the salt.
Answer:
1.Sieving. Sieving is a simple technique for separating particles of different sizes. A sieve such as used for sifting flour has very small holes