9th science IS MATTER AROUND US PURE

S.No.	List of Questions of chapter "IS MATTER AROUND US PURE"
	In text Questions page number
1	What is meant by a puresubstance?
2	List the points of differencesbetween homogeneous andheterogeneous mixtures.
	In text Questions page number 18
1	Differentiate between homogeneousand heterogeneous mixtureswith examples.
2	How are sol, solution andsuspension different from eachother?
3	To make a saturated solution,36 g of sodium chloride is dissolvedin 100 g of water at 293 K.Find its concentration at thistemperature.
	In text Questions page number 24
1	How will you separate a mixturecontaining kerosene and petrol(difference in their boiling pointsis more than 25ºC), which aremiscible with each other?
2	Name the technique to separate(i) butter from curd,(ii) salt from sea-water,(iii) camphor from salt.
3	What type of mixtures areseparated by the technique ofcrystallisation?
	In text Questions page number 24
1	Classify the following aschemical 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 waterbreaking down into hydrogenand oxygen gases,• dissolving common salt inwater,• making a fruit salad with rawfruits, and• burning of paper and wood.
2	Try segregating the thingsaround you as pure substancesor mixtures.
	Textbook Exercise
1	Which separation techniques will you apply for the separationof the following?(a) Sodium chloride from its solution in water.(b) Ammonium chloride from a mixture containing sodiumchloride 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.
2	Write the steps you would use for making tea. Use the wordssolution, solvent, solute, dissolve, soluble, insoluble, filtrateand residue.
3	Pragya tested the solubility of three different substances at different temperatures and collected the data as given below (results are given in the following table, as grams of substance dissolved in 100 grams of water to form a saturated solution).(a) What mass of potassium nitrate would be needed toproduce a saturated solution of potassium nitrate in50 grams of water at 313 K?(b) Pragya makes a saturated solution of potassium chloridein water at 353 K and leaves the solution to cool at roomtemperature. What would she observe as the solutioncools? Explain.(c) Find the solubility of each salt at 293 K. Which salt hasthe highest solubility at this temperature?(d) What is the effect of change of temperature on thesolubility of a salt?
4	Explain the following giving examples.(a) saturated solution(b) pure substance(c) colloid(d) suspension
5	Classify each of the following as a homogeneous orheterogeneous mixture.soda water, wood, air, soil, vinegar, filtered tea.
6	How would you confirm that a colourless liquid given to you ispure water?
7	Which of the following materials fall in the category of a “puresubstance”?(a) Ice(b) Milk(c) Iron(d) Hydrochloric acid(e) Calcium oxide(f) Mercury(g) Brick(h) Wood(i) Air.
8	Identify the solutions among the following mixtures.(a) Soil(b) Sea water(c) Air(d) Coal(e) Soda water.
9	Which of the following will show “Tyndall effect”?(a) Salt solution(b) Milk(c) Copper sulphate solution(d) Starch solution.
10	Classify the following into elements, compounds and mixtures.(a) Sodium(b) Soil(c) Sugar solution(d) Silver(e) Calcium carbonate(f) Tin(g) Silicon(h) Coal(i) Air(j) Soap(k) Methane(l) Carbon dioxide(m) Blood
11	Which of the following are chemical changes?(a) Growth of a plant(b) Rusting of iron(c) Mixing of iron filings and sand(d) Cooking of food(e) Digestion of food(f) Freezing of water(g) Burning of a candle.