CLASS IX PRACTICAL PROCEDURE

SEPERATION OF MIXTURES

AIM: To seperate the following mixtures into pure substances

(i) Mixture of Iron fillings and sand

(ii) Mixture of Ammonium chloride and Sodium chloride

(iii) Mixture of oil and water

(iv) Mixture of two coloured inks

APPARATUS REQUIRED:

Separating funnel, funnel, beaker, china dish, funnel etc

CHEMICALS AND SUBSTANCES REQUIRED:

Ammonium chloride, sodium chloride, oil, water, mixture of red and blue ink, iron fillings , sand

PROCEDURE:

SEPARATION OF IRON FILLINGS AND SAND

This method of seperation is based on magnetic property.

(i) Mixture of iron fillings and sand is taken in a china dish.

(ii) place a bar magnet/ magnet in the mixture.

(iii) When magnet is placed we find some particles getting attached to it.

(iv) Remove the particles attached to the magnet into an empty china dish

(v) Repeat the procedure of placing the magnet in the mixture until no particles get attached to it.

(vi) Now the substances present in the mixture got seperated.

(vii) Iron fillings have the property of getting attracted to the magnet, and that is how we separate them from mixture of sand particles.

SEPARATION OF AMMONIUM CHLORIDE AND SODIUM CHLORIDE

(i) Ammonium chloride undergoes sublimation on heating, making use of this property it is separated from sodium chloride mixture.
(iii) The mixture is taken in a china dish and closed with a funnel and plugged with cotton.
(iv) The china dish containing the mixture is placed on a wire guaze of tripod stand and heated with a bunsen burner.
(v) After some time we find fumes inside the funnel, these fumes condense on walls of the funnel.
(vi) Heating is done untill all ammonium chloride gets sublimed.
(vi) Then we will be left over with sodium chloride in the china dish.
(vii) This is how the mixture is seperated.

SEPARATION OF MIXTURE OF OIL AND WATER

(i) Mixture containing oil and water is taken into a separating funnel and left undisturbed for few minutes by closing its stopper.
(ii) After few minutes we find oil and water getting separated into two layers, the denser water is present in the lower layer and lighter oil in the upper layer of the separating funnel.
(iii) Slowly without disturbing the funnel the stopper is opened to run down the water, stopper is close immediately when the water layer is run down completely.
(iv) Then we will be left over with oil in the separating funnel and water outside in which it is collected.

SEPARATION OF RED AND BLUE INK PRESENT IN MIXTURE

(i) To separate red colour ink from blue colour ink we use method called CHROMATOGRAPHY.
(ii) In this method a filter paper is taken and on four sides margin is drawn, from the bottom 1cm above a line is drawn.
(iii) on this line at the centre with a needle the mixture of ink is placed.
(iv) This paper is kept in a beaker containing alcohol and left undisturbed for sometime.
(v) After some time we find the two colours getting separated .
(vi) This is because, when the paper spotted with mixture of colours is placed in alcohol, the colours get dissolved in it, as alcohol rises up the paper the colours also depending upon their speed also rise up get separated.

CLASS X SA-1 PRACTISE QUESTIONS ANSWERS

ARMY PUBLIC SCHOOL GOLCONDA

PRACTISE QUESTIONS ANSWERS(SA-1) CLASS –X

1.       In combination reactions two substance combines to form one compound and in decomposition reactions a compound breaks down into two or more substances, so they are opposite to each other. 2.      Ionic Bond 3.      Sulphide ore 4.      Carbon dioxide gas. Pass this gas into lime water, it turns into milky white. 5.      KCl(aq)   + AgNO3 (aq)    -------------------------   AgCl(s)        +  KNO3(aq), it’s a double displacement reaction. 6.      X is Calcium Oxide.                                                                                                                                            CaO(s)         +       H2O (l)   -----------------------    Ca(OH)2(aq)   7.      (a)  C +  O2  -------------------------   CO2                                                                                                           (b) C6H12O6 +  6O2  6CO2 +  6H2O +  energy                                                                                            (c)  Sulphur dioxide and Sulphur Trioxide. 8.      (i)  It will not undergo any colour change because the solution of Na2SO4(sodium sulphate) in water is almost neutral.                                                                                                                                                 (ii)  Concentrated sulphuric acid is highly hygroscopic. It absorbs moisture from air and gets diluted. Since the volume increases, the acid starts flowing out of the bottle. 9.      Washing soda - Na2CO3 . 10 H2O Baking soda : NaHCO3               Baking soda is an ingredient of anatacids. It neutratlises HCl released in stomach and ceases  stomach ache.                                   NaHCO3 + HCl ----------------------------            NaCl + CO2 +H2O 10.  Definition : Homogeneous mixture of two or more metals or a metal and a non metal. Preparation : (i) Melting the primary metal. (ii) Dissolving the other elements in a definite proportion and cooled to room temperature.                                                   Alloy Constituent Uses                       Brass Cu and Zn in making utensils 1                       Bronze Cu and Tin making statue,  medal                           Solder Pb and Tin in soldering . 11.  (i)  In nature metals are found in free and combined forms, i.e. as their compounds.                                                                                                                                                    (ii)  With oxygen : All metals combine with oxygen and form metal oxides.                                                                                                                                                                    For examples : When copper is heated in air it combines with oxygen and forms copper oxide.  Metals react with water : For example, sodium reacts with cold water, Mg reacts with hot water, Fe reacts with steam or any other examples.                                                                                                    With Acids : Metals react with acids and form salt and hydrogen gas.                                                   For example : Magnesium reacts with dilute hydrochloric acid and forms magnesium chloride and water.  Equation :  2Cu+O2 -------------------------   2CuO Mg + 2HCl----------- MgCl2 + H2                                                                                                                                                                        2Na(s)+  2H2O(l)------------------------------------ 2NaOH(aq)        +     H2 (g) 12.  (b) 13.  (b) 14.  ( c ) 15.  (d) 16.  (c) 17.  CaCO3          -------------------------------  CaO        +       CO2, Calcium carbonate decomposes to calcium oxide and carbon dioxide on heating. 18.   They get tarnished by reacting with atmospheric air to form silver sulphide. 19.  Oxides which react with both acids and bases are called amphoteric oxides. Example ZnO and  Al2O3. 20.                 2 FeSO4 -----------------------------------  Fe2O3  +  SO2  +  SO3, it is thermal decomposition reaction. 21.       Pb(NO3)2 - lead nitrate                                                    2 Pb(NO3)2  ----------------------------       2 PbO + 4 NO2 + O2 22.   (a) Quick lime reacts vigorously with water to produce slaked lime releasing a large amount of heat.                                                                                                                                                                                 (b) CaO   +  H2O  --------------------------------   Ca(OH)2                                                                                                                                                                                                            (c) Combination reaction . 23.   Sodium Carbonate Decahydrate                                                                                                    Na2CO3.10H2O                                                                                                                                                                           Obtained by heating baking Soda and Recrystallization                                                                                                                                                2NaHCO3    ----------------------------- Na2 CO3 +   H2O    + CO2                                                                                                                                                                               Na2CO3 + 10H2O  -------------------------------Na2CO3.10 H2O 24.    (a) Chlor-alkali-process - explanation                                                                                                       (b) (i) 7 (ii) less than 7 25.    (i) Iron forms its oxide by reacting with oxygen in air. Design of activity - Conditions needed for iron nails to rust. (Air, water) Explanation.                                                                                                                                                                                    (ii) Rusting of iron can be prevented by painting the surface of iron object. Oxygen and moisture of the atmosphere will not be able to come in direct contact with the surface of iron. 26.  (a) 27.  (b) 28.  ( c) 29.  (a)