reactions and to classify them. 1 To and observe the following (v) Decomposition reaction (@) Combination reaction (@ Double displacement reaciion, cement reaction i. Action of water on quick ae eels i ation ofheat on ferous Suphate SESE H ion between iron nail and copper p! ; / iii, Reaction um sulphate solution and barium chloride solution, iv. Reaction between sodit (0) Displat i Experiment 3(A) To perform and observe the action of water on quick lime and classify it. | Principle | if Quick lime is Calcium Oxide (CaO). On combining with water it reacts vigorous: ~~ 1 Hydroxide (Ca(OH),) which is also known as slaked lime. | This reaction occurs with the evolution of a large amount of heat, therefore i 1h exothermic reaction. © Itcan be represented in the form of a chemical reaction as — 1 | C206) + #00) —> CaoOH, + It Quick time Water Slaked lime h } © In this reactic it i combination ate Substances simply combine to form a new product i © The product formed Ca i . 7 fi through it (OH), is also known as lime water which turns milky w=" Asit contains (OHD i (OF) ons. I's turns red litmus blue and hence is basic in nat | es } } © Quick lime } © Water ® Red litmus paper ° Dropper i * Glass rod Scanned with CamScannerInference «A vigorous reaction occurs ¢ A single substance known as with a hissing sound. * Gicium hydroxide is formed. | 7) Frocedure (Observation “qoke a small quantity of i icklime in a beaker. Slowly to subi add water to submerge the , Evolution of a large amount © Classified as combination nee en of eat and the beaker reaction. stir with a clean glass rod. becomes hot. . 5 gently touch the beaker. | | “¢Exothermic reaction. fe Thered litmus tums blue. product formed is basic in Using a dropper carefully Jace a drop of solution on | nature. the litmus paper. Never put quicklime in water as it may splash Asitisan exothermic reaction water should be added drop by drop. + Donot touch solution in beaker, it may burn the skin. Loy ment 3(B) ‘To perform and observe the action of heat on Ferrous ium 1s Sulphate crystals and to classify it. © The crystals of ferrous sulphate are light green in colour. This colour is due to the presence of water sset of crystallization. © Onheating the crystals, a thermal decomposit to brown due to the formation of ferric oxide. © Smell of burning sulphur is obtained due to the evolution FeS0,¢7H,0(8) > F806) + 7,018) Green Dirty white FeSO,s) —2> Fe,0,6) + SOX8) + sO,(g) Ferrous sulphate Ferric Oxide Sulphur dioxide Sulphur trioxide (green) (Brown) tion reaction takes place and the green colour changes of gases SO, and SO. 39 Motch Reactions a Scanned with CamScanner* A single reactant breaks down into three new products on heating, hence it is an ¢ nx decomposition reaction. * Sulphur dioxide and sulphur trioxide tum blue litmus red, proving that both gases are acidic in o Requirements © Test tubes Test tubes holder © Ferrous sulphate cys © Burner © Blue litmus Procedure | Observation | Inference © Take a clean dry test tube, © Green colour changes to first ® A single compound fer: add about 59 of crystals of dirty white and then brown. sulphate decomposes. ® ferrous sulphate. three simple compoun classified as decompos reaction. |. Tiny droplets of H,O near © Using a test-tube holder heat _neck of test tube. | the test tube on a Bunsen , burner keeping the mouth of test tube away from your Colourless gas with an irritating smell of burning Initial colour change lossof water ofcrystallizs ee sulphur. - |. Moist bidfe litmus turns red ® The gases are acidic inns. * After heating colour of j{°h out crystals is noted. | ° «The gasevolved is smelt. | a Moss bh © A wet blue litmus is brought itmas paper near mouth of test tube. | | / | | tee | © Use hard gl r- Shes tes tubes as boling tubes, ° Keep mouth of test tube away from your Scanned with CamScannertur, ‘To perform and observe reaction between an iron nail and copper sulphate solution and classify it. ¢ When an iron nail is kept in a blue coloured soluti iron bei i kep . solution of copper sulphate CuSO, then iron being more reactive displaces Cu ions from is salt soltion (Cus0,) and a green coloured solution of FeSO, is obtained. The blue colour changes to green due to the formation of Fe” ions in the solution. 2g? Fels) + Cu*SO* aq) —> Fe SO* aq) + — Culs) Iron Coppe i opper sulphate Ferrous sulphate Copper Grey) (Glue) ‘ight green) (Reddish brown) ‘¢_Ironnails get coated by a deposition of copper metal and turn reddish brown in colour. ° Tisisadisplacement reaction in which iron being more reactive displaces copper from itssalt solution. Fe’ gets oxidized due to loss of electrons while Cu gets reduced due to gain of electrons. = | Test tubes © Copper sulphate solution © Sand paper © Iron nails © Test tube holder © Clamp stands = Me Cu" ions are replaced by sulphate slowly fades to Fe” ions. bluish green and finally toa ¢ Tron is more reactive than green colour. copper and displaces it from ‘A brown coating is seen on its salt solution. theironnail kept immersedin ° This reaction is classified as a the copper sulphate solution. _ single displacement reaction. No change is observed in the iron nail kept in the empty test tube. Clamp two clean test tubes to two clampstand. | Place an iron nail cleaned” with sand paper in each test tube in the first test tube add about 10 ml of copper sulphate solution. Do not add anything in the ° second test tube with iron nail. | Wait for about 30 minutes | and note your observations. Al Scanned with CamScanner© The iron nails should be cleaned properly to remove any rust using sand paper. i © Freshly prepared solution of copper sulphate should be used. —_ $$ qEy> $$ To perform and observe reaction between sodium sulphate solution and barium chloride soi, to classify it. a © Aqueous solutions of both sodium sulphate and barium chloride are colourless. A * When aqueous solution of sodium sulphate containing sodium ions (Na’) and sulphate ions is added to an aqueous solution of barium chloride containing barium ions (Ba) and chor, (CI) then an exchange of metal ions takes place. An insoluble precipitate of barium sulphates which is white in colour. Na,SO(aq)_ + ~—_BaCl(aq) —> 2NaCKaq) + BaSO,L A Sodium sulphate Barium chloride Sodium chloride Barium sulphate (colourless) (colourless) (colourless) (white) A © Since, there is displacement in both the reactants, it is a case of double displacement reaction | Requirements ; © Sodium sulphate solution © Barium chloride solution © Test tubes © Beaker Take 5 ml of an aqueous solution of barium chloride ‘in one clean test tube, An equal volume of __ Inference An insoluble whl’ of barium sulpha * A clear solution will be visible formed © Awhite pptis formed which settles | at the bottom of the beaker. ; above thi sons! i sodium sulphate is taken | O° iS PP. | Aclear solutions in another clean test tube, bes) —_? chloride is forme’ * Take a beaker and pour, **S°.SeWle =" <= Sec1souten © This reaction is clo both solutions in it, as a double displ@" reaction. Stir and leave undisturbed | for some time, \ Laboratory Manual Che Scanned with CamScanner