Malini Seshadri Solutions for Chapter: Separation of Substances, Exercise 2: STEP IN

Write the method(s) that you would use to separate the salt and water mixture. (Evaporation/Filtration)

Write the method that you would use to separate the husk and grain mixture. (Threshing/Winnowing)

Many mixtures of substances exist in the environment. Place a  next to the mixtures that occur naturally and a ✘next to the mixtures that are made by humans.

Water and oxygen 

Many mixtures of substances exist in the environment. Place a  next to the mixtures that occur naturally and a ✘ next to the mixtures that are made by humans.

Kerosene and water 

Perform this activity and answer the questions. Add salt half a teaspoon at a time to a clear glass of water, stirring well each time.

What happens to the colour of the water after you have dissolved four or five teaspoons of salt?

Perform this activity and answer the questions. Add salt half a teaspoon at a time to clear glass of water, stirring well each time.

If you keep adding salt, does it go on dissolving? What does this tell you?

Perform this activity and answer the questions. Add salt half a teaspoon at a time to a clear glass of water, stirring well each time.

If more salt does not dissolve in the water, where does it go? Does it sink to the bottom of the glass or rise to the top? Why?

Perform this activity and answer the questions. Add salt half a teaspoon at a time to a clear glass of water, stirring well each time.

If you now heat the glass of salt water, can you dissolve more salt in it? What does this tell you?