Question

6. A student adds a mixture of oil, sand and salt in a beaker of water and stirs it. The student stops stirring, and observes that the salt is no longer visible. It is also observed that the oil floats on the top and the sand sinks to the bottom of the beaker.

a. Why does oil float on water?
b. Why is salt no longer visible after the stirring?
c. How can you separate the components of this mixture?​

Answer 1

Step-by-step explanation:

a)oil floats on water because oil has less dense than the water.

b) since salt dissolve in water.

c) 1. Decantation -

Oil floats on water (oil is insoluble in water), so it can be decanted easily.

2. Filtration-

Filter the mixture and sand will be separated from the water (as it is insoluble in water), and only salt solution will be left.

3. Evaporation-

The salt solution can be evaporated, by this, the salt will separate out.