How would you test the purity of a substance?

2

(a)

Water is a compound and not a mixture. List two reasons to justify your answer.

2

(a)

How will you prepare a saturated solution of copper sulphate in water at 50⁰ C? what will happen if this solution is allowed to cool?

2

(a)

What is the main difference between aqueous and non-aqueous solutions?

2

(a)

(a) 20 g of sodium chloride is dissolved in 100 mL of water. How will you test whether the given solution is saturated or unsaturated at the given temperature?
(b) Suggest any one method by which we can increase the solubility of saturated solutions.

2

(a)

(a) How can we separate a mixture of two immiscible liquids?
(b) Can we separate alcohol dissolved in water by using a separating funnel?If yes, then describe the procedure.if not, Explain.

2

(a)

Write any two applications of crystallisation.

2

(a)

Enumerate any two differences between simple distillation and fractional distillation.

2

(a)

Define Crystallisation. Why is crystallisation technique considered better than simple evaporation to purify solids?

2

(a)

You are given a mixture of sand, water and mustard oil. How will you separate the component of the mixture?

2

(a)

How will you separate a mixture of common salt, camphor and iron fillings. Describe the process.

2

(a)

Does the energy changes take place both in physical and chemical changes?

2

(a)

Give three reasons to support that brass is a mixture, not a compound.

2

(a)

How many elements are non-metals? out of these, how many are solids, liquids and gases?

2

(a)

how would you confirm that a colourless liquid given to you is pure water?

2

(a)