Page 1 :
EXERCISE - 1, , Question 1., Select homogeneous and heterogeneous mixtures from the, following:, , Salt solution, petrol and water, sand and charcoal, alcohol, and water, air dissolved in water, air, sea water, fruit juices,, mist, brass., , Answer:, , Homogeneous mixture : Salt solution, alcohol and water, air, dissolved in water, sea water, brass., , Heterogeneous mixture: Sand and charcoal, air, fruit juice, mist,, petrol and water., , Question 2., Define the following :, , (a) Pure substance, , (b) Impure substance, , (©) Alloy, , (d) Solution, , (e) Heterogeneous mixture, , (£) Homogeneous mixture, , Answer:, , (a) Pure substance : “Pure Substance is either element or compound., It contains the same kind of atom or molecules and has a definite set of, physical and chemical properties.”, , (b) Impure substance : “A substance in which some other, substances are also present in smaller or larger amounts is called an, impure substance. Mixtures are impure substance., , Example of impure substance is air., , (© Alloy :“A homogeneous solid mixture of two or more metals or a, metal and a non-metal is called an alloy.”