Classify each of the following as a homogeneous or heterogeneous mixture.
soda water, wood, air, soil, vinegar, filtered tea.
Explain the following giving examples.
(a) Saturated solution
(b) Pure substance
(c) Colloid
(d) Suspension
Write the steps you would use for making tea. Use the words
solution, solvent, solute, dissolve, soluble, insoluble, filtrate
and residue.
Which separation techniques will you apply for the separation
of the following?
(a) Sodium chloride from its solution in water
(b) Ammonium chloride from a mixture containing sodium
chloride and ammonium chloride
(c) Small pieces of metal in the engine oil of a car
(d) Different pigments from an extract of flower petals
(e) Butter from curd
(f) Oil from water
(g) Tea leaves from tea
(h) Iron pins from sand
(i) Wheat grains from husk
(j) Fine mud particles suspended in water
Classify the following as chemical
or physical changes:
• cutting of trees,
• melting of butter in a pan,
• rusting of almirah,
• boiling of water to form steam,
• passing of electric current,
through water and the water
breaking down into hydrogen
and oxygen gases,
• dissolving common salt in
water,
• making a fruit salad with raw
fruits, and
• burning of paper and wood.
To make a saturated solution, 36 g of sodium chloride is dissolved in 100 g of water
at 293 K. Find its concentration at this temperature.
Differentiate between homogen eous and heterogeneous mixtures with examples.