S.B.O.A.Matric.Hr.Sec.School

S.B.O.A.MATRIC.HR.SEC.SCHOOL

ANNANAGAR CHENNAI–600101

STD–XCHEMISTRYSTUDYMATERIAL

9.SOLUTIONS

I ChoosetheCorrectAnswer

1.Atruesolutionisahomogeneousmixtureofsoluteandsolvent.Chalkpowderinwaterisa heterogeneousmixture.Isitatruesolution?

Ans:No.Itisa suspension

2.Solutionthatcontainswaterasthesolventiscalledaqueoussolution.Ifcarbondisulphide isa solventinagivensolution,thenthesolutioniscalled

Ans:Non-aqueoussolution

3.Solubilityofcommonsaltin100gwateris36g.If20gofsaltisdissolvedinithowmuchmore is requiredtoattainsaturation.

Ans:16g

4. If twoliquids aremutuallysoluble,theyarecalled liquids.(miscible,immiscible)

Ans:miscible

5. Whensunlightpassesthroughwindowof theclassroomsitspathisvisible.Thisisdueto

of light.(reflection,scattering)

Ans:scattering

6.Theparticlesinvariousforms arevisible onlyunderultramicroscope.Asolutioncontainingsuch particlesiscalled (Truesolution/colloidalsolution)

Ans:Colloidalsolution

7. The mixture ofgasesusedbydeepseadiversis (Helium-oxygen,oxygen-nitrogen)

Ans:Helium-oxygen

8.Earthsoilcannotstore morenitrogenthanitcanhold.Hence earthsoilis referredtobeinastate of (saturation,unsaturation)

Ans:saturation

9. Inanendothermic process,solubilityincreaseswith intemperature.(increase,decrease)

Ans:increase

10. Saltsolutioncontainingcommonsaltinwateris anexamplefor

a)binarysolution b)trinarysolution c)Suspension d) Colloidalsolution

11. The numberofcomponentsinabinarysolutionis

a)one b)two c) three

12. Particlesofatruesolutionare

a)visibletothe nakedeyec)notvisible even underultramicroscope

13. Whichof thefollowingisatruesolution?

a)sugar inwater b)milkpowderinwater c)chalkpowderinwater d)allof these

14. Sizeofparticleincolloidalsolutionis

a)1Ato10A b)10Ato2000A c)10Ato100A d)morethan2000A

15. Whichis correct regardingcolloidalsolutions?

a)translucent b)scatterlight c)heterogeneous d)allare correct

16. Inwhichof thefollowingtheparticlesdiffusereadily?

a) True solution b) Colloidalsolution c)suspension d)none of these

17. Whichof thefollowingscatterslight?

a)Sugarinwater b)Chalkpowderinwater c)Milkpowderinwaterd)allof these

18. Whichisanon-aqueoussolution?

a)Sugarinwater b)Commonsaltinwater c)sulphur incarbondisulphided)none

19. Non-aqueoussolventis/are

a)benzene b)ether c) CS2 d)allthe above

20. / Whichof thefollowingisasaturatedsolution?
a)5gNaClin100gwater c)20gNaClin100gwater / b)10gNaClin100gwater
d)36gNaClin100gwater

21. Inwhichof thefollowingsolutions,bothsoluteandsolvent aresolids?

a)cork b)cheese c)alloys d)smoke

22. Anexampleforasolution containingliquidsoluteingassolventis

a)sodawater b)cloud c)cork d)smoke

23. Scatteringoflightbycolloidalparticlesisknownas

a) Tyndalleffect b)Brownianmotion c)Zeemaneffect d)none

24. RobertBrownobservedthe motionof theparticlesin_

a)solutionofsugarinwater b)solutionofsaltinwater

c)suspensionofpollengrainsinwater d)suspensionofchalkpowderinwater

25. Whichof thefollowing factors affectsolubility?

a) temperature b)pressure c)natureofsoluteandsolvent d)allthe above

26. SolubilityofKNO3

a) increases b)pressure c)natureofsoluteandsolvent d)allthe above

27. Solubilityof CaO

a)increases b)decreases c)remains constant d)none of these

28. Solubilityof CO2gasinwater withtheincreaseinpressure

a) increases b)decreases c)remains constant d)none of these

29. At20°Cthesolubilityof CuSO4 inwater(100g)is

a)36g b)20.7g c)10g d)92g

30. SolubilityofCuSO4inH2Ois at20oC(20.7g/36g)

Ans:20.7g

CHAPTER – 9: SOLUTIONS

MODEL EVALUATION - OBJECTIVES

A true solution is a homogeneous mixture of solute and solvent. Chalk powder in water is a heterogeneous mixture or suspension.
A solution that contains water as the solvent is called an aqueous solution. If carbon-disulphide is a solvent in a given solution, then the solution is called non- aqueous solution.
The solubility of common salt in 100g of water is 36g. If 20g of salt is dissolved in it. 16g of NaCl is required to attain saturation.
If two liquids are mutually soluble, they are called miscible liquids.
When sunlight passes through the window of a classroom, its path is visible. This is due to scattering of light.
The particles in various forms are visible only under an ultra microscope. A solution containing such particles is called, colloidal solution.
The number of components in a binary solution are/is two.
The mixture of gases used by deep-sea divers is helium-oxygen.
Soil cannot store more nitrogen than it can hold. Hence soil is said to be in a state of saturation.
In an endothermic process, solubility increase with increase in temperature.
Aquatic species are more comfortable in cold water because as the temperature decreases, the solubility of dissolved oxygen increases.

8ADDITIONAL QUESTIONS:-

The process of food assimilation by man is in the form of solution.
Blood and lymph are in the form of solution to decide the physiological activity of human beings.
A solution is a homogeneous mixture of two or more substances.
All solutions exist in homogeneous form.
Homogeneous is the state in which two or more substances are uniformly present in a given mixture.
Salt solution is an example for binary solution.
In a solution, the component present in less amount by weight is called solute and the component present in a larger amount by weight is called solvent.
Solvent is a dissolving medium.
Solute + Solvent → Solution.
Based on the particle size of the substance, the solutions are divided into three types.
True Solution is a homogeneous mixture .(sugar in water)
Colloidal Solution is a heterogeneous mixture/ two phases/dispersed phase and dispersion medium.

The substance distributed as particles is called dispersed phase.
The continuous phase in which the colloidal particles are dispersed is called dispersion medium.
Dispersed phase + Dispersion medium → Colloidal solution
Milk powder (Fat, Vitamin, Protein) and water forms Milk (colloid)
Scattering of light is called Tyndall effect.
Suspension is a heterogeneous mixture of small insoluble particles in a solvent.
In a suspension, the solid particles stay in clusters (large) in water.
A mixture of chalk powder and water forms suspension.
The phenomenon by which the colloidal particles are in continuous random motion is called Brownian movement.
Brownian motion is named after ROBERT BROWN, a biologist.
Brownian motion of the particles is suspension of pollen grains in water.
When a beam of light is allowed to pass through a true solution, some of the light will be absorbed and some will be transmitted.

The particles in true solution are not large enough to scatter light.
Solution of sulphur in carbon disulphide in non-aqueous solvent.
Non-aqueous solvent-benzene, ether, acetone to dissolve organic compounds.
If light is passed through a colloidal solution, the light is scattered by the larger colloidal particles and the beam becomes visible.
Unsaturated solution is a solution in which more of the solute can be dissolved at a given temperature.

In saturated solution addition of solute is possible till the solution reaches saturation.

Supension

Particle size in1A = 10-10m.
Size of true solution 1A to 10 A, Colloidal solution 10A to 2000 A Suspension solution More than 2000A.
Appearance – True solution -Transparent , Colloidal solution –Translucent, Suspension – Opaque
Visibility of particles- True solution -Not visible even under ultra

Microscope, Colloidal solution - Visible under ultra microscope, Suspension-Visible to the naked eye

Nature –True solution - Homogeneous, Colloidal and Suspension- Heterogeneous in nature.
Diffusion of particles- True solution -diffuses rapidly, Colloidal solution-Diffuses slowly, Suspension-Diffusion does not occur.
Scattering effect –True solution-Does not scatter light, Colloidal solution- Scatters light, Supersaturated solution-Does not scatter light.
Super Saturated Solution a solution which has more of solute than the saturated solution at a given temperature is called super saturated solution.
Nitrogen in soil is an example for saturated solution in nature.
Soil cannot store more nitrogen (N2) than it can hold in saturation state.
Solubility of a solute in a given solvent at a particular temperature is defined as the number of grams of solute necessary to saturate 100g of the solvent at that temperature.
Solubility of CuSO4 in H2O is 20.7g at 20oC.
Alloy is an example of solid in solid.
Sugar solution is an example of solid in liquid.
Smoke is an example of Solid in gas.
Cheese is an example of Liquid in solid.
Milk is an example of liquid in liquid.
Cloud is an example of liquid in gas.
Cork is an example of gas in solid.
Soda water is an example of gas in liquid.
A solution containing less amount of solute is known as a dilute solution
A solution containing a large amount of solute is known as a concentrated solution.
Dilute and concentrated are relative terms and they have only quantitative meaning.
Calcium chloride is a dehydrating agent, and it absorbs moisture.
Solubility of Salt= Weight of salt× 100

Weight of solvent

100gl of water can dissolve 36g of NaCl at250C to attain saturation
In endothermic process, solubility increases with increase in temperature.
Solubility of KNO3 increases with the increase in temperature.
In exothermic process, solubility decreases with increase in temperature.
Solubility of CaO decreases with increase in temperature.
Solubility of oxygen is more in cold water.
Solubility of a solute in a solvent depends on the nature of both solute and solvent.
A polar compound dissolves in a polar solvent.
. Common salt dissolves in water.
A polar compound is less soluble (or) insoluble in a non-polar solvent.
Effect of pressure is observed only in the case of gases in liquids.
An increase in pressure increases the solubility of a gas in liquids.
CO2gas is filled in soft drinks using the effect of pressure.
S0lubility of ionic compounds at 250c in100g of water can dissolve NaCl 36 g /NaBr 95 g/NaI 184 g/NaNO3 92g to attain saturation.
At a given temperature, the mass of gas dissolved in a fixed volume of liquid is directly proportional to the pressure of the gas on the surface of the liquid. This is called Henry’s Law.

IChoose the Correct Answer

11.CHEMICALREACTIONS

1. Zn+2HC1------ZnCl2+H2↑

Theabovereactionis anexample of

a) Combinationreaction b)Doubledisplacement reaction

c)Displacementreaction d)Decompositionreaction.

2. Areddishbrowncolouredelement'X'onheatinginairbecomesblackcolouredcompound'Y'.

XandYare and(Cu,CuO/Pb, PbO).

Ans:Cu, CuO

3.AstudenttestedthepHofpurewaterusingapHpaper. Itshowedgreencolour.Ifa pHpaperisusedafter addinglemonjuiceintowater,whatcolorwillhe observe? (Green/Red/Yellow)

Ans:Red

4. Chemicalvolcanois anexample of(combinationreaction/decompositionreaction)

Ans:decompositionreaction

5. When crystalsofleadnitrateonheatingstronglyproducesa gasandthe colourof thegasis

Ans:Nitrogendioxide(NO2)gas,Reddishbrown

6. Whenaqueoussolutionofsilvernitrateandsodiumchloridearemixedprecipitateisimmediatelyformed

(white/yellow/ red).

Ans:White

7.Zinc candisplacealuminiummetalfromaquoussolutionofaluminiumsulphate(zinc ismore reactivethanaluminium/ aluminiumismorereactivethanzinc ).

Ans:zincismorereactivethanaluminium

8.Toprotecttoothdecay,weareadvisedtobrushourteethregularly.Thenatureof thetoothpaste commonlyusedis innature.

Ans:basic

9. Vinegarispresentinacetic acid.Curdcontains acid (Lactic acid/Tartaric acid).

Ans:Lactic acid

10. pH=- log10[H+].ThepHofasolutioncontaininghydrogenionconcentrationof0.001Msolutionis

(3/11/14)

Ans:3

11. The lustrouswhitecolourof thesilverankletslowlychangesintoslightlyblack colour.

Thisiscalledtarnishingofsilver.Thisisduetotheformationof

a)Silver sulphide (Ag2S) b)Silveroxide(Ag2O) c)Silvercarbonated)Silvernitrate

12. Tarnishingofsilverisduethereactionbetweensilverand

a)oxygen b)hydrogensulphide c)carbondioxide d)nitrogen

13. Quicklime is

a)calciumhydroxide b)sodiumhydroxide c)calciumoxideCaO d)sodiumcarbonate

14. Slakedlime is

a)calciumhydroxideCa(OH)2b)sodiumhydroxide c)calciumoxide d)sodiumcarbonate

15. Whendilutehydrochloric acidis addedto calciumcarbonate,briskeffervescence isproduced.

Thisisduetothe evolutionof gas

a)CO2 b)O2 c)H2 d) Cl2

16. Whichof thefollowingisusedforwhite washing?

a)Sodium hydroxide b)calciumhydroxidec)sodiumchlorided)washingsoda

17. Chemical formulaformarble is

a)CaCO3 b) CaO c)Na2CO3 d) Ca(OH)2

18. Whencoppercarbonateisheated,colourischangedfrom

a)bluetowhite b)greento black c)greentored d)blue toblack

19. Whichislessreactive?

a)Fe b)Zn c)Pb d)Cu

20. / Whichofthefollowingreactiondoesnotoccur?
a)Fe+CuSO4------FeSO4+Cu c)Zn+ CuSO4------ZnSO4+Cu / b)Pb+CuCl2 ------PbCl2 +Cu
d)Cu+ZnSO4 ------CuSO4 +Zn

21. Thecatalystusedinthe decompositionofpotassiumchlorateis

a)manganesedioxideb)magnesiumoxide c)Nitrogendioxide d)noneofthese

22. 2Mg+O2 ------2MgO. This is anexamplefor reaction

a)combination b)decomposition c)displacement e)elimination

23. Ourbodymetabolismiscarriedoutbymeansof secretedinourstomach.

a) hydrochloricacid b)sulphuric acid c)nitric acid d)formicacid

24. Substanceswith'sourtaste'are

a)acidsb)basesc)salts d)noneofthese

25. Whichofthefollowing isweak acid?

a)HCl b)HNO3 c)H2SO4 d)CH3COOH

26. Formicacid(HCOOH)is

a)mineral acid b)strongacid c)weakacid d)dibasicacid

27. Aceticacid(CH3COOH)is

a)mineral acid b)tetrabasicacid c)monobasicacid d)dibasicacid

28. Theacidpresentingrapeis

a)aceticacid b)malicacid c)tartaricacid d)lacticacid

29. gasburnswitha'pop'ingsound

a)Hydrogen b)Oxygen c)Nitrogen d)Chlorine

30. Tribasicacidis

a)H2SO4 b)CH3COOH c)H3PO4 d)H3PO3

Monobasicacid / HCl,HNO3,CH3COOH
Dibasicacid / H2SO4,H2CO3
Tribasicacid / H3PO4
Organicacids(Weak acids) / HCOOH,CH3COOH
InorganicacidsorMineralacids
(Strongacids) / HCl,HNO3,H2SO4

31. Whichofthefollowing doesnot liberatehydrogengasonreactionwithacids?

a)Zn b)Mg c)Ag d)alltheabove

Note:AgCudonot liberatehydrogengasonreactionwithacids

32. Limestone, chalkandmarblearedifferentphysicalformsof

a)calcium carbonateb)sodiumcarbonate c)potassiumcarbonated)noneofthese

33. Washingsoda is

a)Na2CO3 b)NaHCO3 c)CaO d)CaCO3

34. Bakingsodais

a)Na2CO3 b)NaHCO3 c)CaO d)CaCO3

35. The gaswhichturnslimewatermilkyis

a)H2S b)O2 c)SO2 d)CO2

36. Metalcarbonates, metalbicarbonatesandmetaloxidesare

a)acidic b)basic c)neutral d)noneofthese

37. Kingofchemicalsis

a)Sulphuricacid b)Nitricacid c)Hydrochloricacid d)Tartaricacid

38. Whichisusedasacleansingagent intoilet?

a)Sulphuric acid b)Nitricacid c)Hydrochloricacid d)Tartaricacid

39. Theatmosphereof Venusismadeupofthickwhiteandyellowishcloudsof

a)Sulphuricacid b)Nitricacid c)Hydrochloricacid d)Tartaricacid

40. Causticsodais

a)NaOH b)KOH c)Ca(OH)2 d)H2SO4

41. Caustic potashis

a)NaOH b)KOH c)Ca(OH)2 d)H2SO4

42. Whichofthefollowing isaweakbase?

a)NaOH b)KOH c)NH4OH d)Allofthese

Strongbases / NaOH,KOH
Weakbases / NH4OH,Ca(OH)2
Monoacidicbase / NaOH,KOH
Diacidicbase / Ca(OH)2,Mg(OH)2
Triacidicbase / Al(OH)3,Fe(OH)3
43. / Whichofthefollowing doesnot reactwithNaOH?
a)Al b)Zn / c)Cu / d)Allofthese
Note:AlZnreactwithNaOH
Cu, Ag, &Crdonot reactwithNaOH
44. / Whichisusedasa medicineforstomachtroubles?
a)NaOH b)Ca(OH)2 / c)Al(OH)3 / d)Mg(OH)2
45. / pHscalewasintroducedby
a)S.P.L. Sorenson b)J.J.Thomson / c)Kelvin / d)Rutherford
46. / pHofanacidicsolutionis
a)7 b)7 / c)=7 / d)=14

47. pHofasolutionis10.What is thepOH?

a)10 b)7 c)0 d)4

48. pH+pOH=

a)14 b)7 c)0 d)5

49. pHoflemonjuiceis

a)4.1 b)2.2-2.4 c)6.5-7.5 d)4.4-5.5

50. Humanbodybecomespronetoviralinfectionslike colds,coughandflu

a)14 b)0 c)9.6 d)6.9

51. Cancercellsthriveinsidethebodyata pHof

a)14 b)0 c)9.6 d)5.5

52. The pHofanormal,healthyhumanskinis

a)4.5to6 b)6.6to7.7 c)2-4 d)7

53. pHof stomachfluidisapproximately

a)0 b)7 c)2 d)10

54. HumanbloodpHrangeis

a)7.35to7.45 b)4.35to4.45 c)8.35to8.45 d)2.35to2.45

55. TheidealpHforbloodis

a)7.4 b)2.4 c)7 d)14

56. pHofnormalsalivarangesbetween

a)4.5to5.5 b)5.5to5.5 c)7.5to8.5 d)6.5to7.5

57. Whiteenamelcoatinginourteethis

a)calcium phosphateb)calciumchloride c)calciumcarbonate d)calciumoxide

58. pHofrainwaterisapproximately

a)0 b)14 c)7 d)5

59. / Rainwateris
a)acidic b)basic c)neutral / d)alkaline
60. / Iftherainispollutedby acidrainoccurs
a)SO2andNO2 b)CO2andCO c)CaOandNa2O / d)noneofthethese
61. / Whichisnormalsalt?
a)NaCl b)NaHSO4 c)Pb(OH)Cl / d)Potashalum
A / B
Normalsalt / NaCl
Acidsalt / NaHSO4
Basicsalt / Pb(OH)Cl
Doublesalt / Potashalum

62. Whichofthefollowing isusedinsoftening hardwater?

a)NaHCO3 b)Na2CO3 c)CaCO3 d)K2CO3

A)MatchtheFollowing:

Acid / Use
Sulphuricacid / Carbattery
Hydrochloricacid / Cleansingagentintoilet
Nitricacid / Productionofammoniumnitrate (fertilizer)
Tartaricacid / Constituentofbakingpowder
Carbonicacid / Aerateddrinks
Saltofbenzoicacid(sodiumbenzoate) / Foodproduction

Base / Use
Sodiumhydroxide / Manufactureofsoap
Calciumhydroxide / Whitewashingthebuildings
Magnesiumhydroxide / Medicineforstomachtroubles
Ammoniumhydroxide / Usedtoremovegreasestainsfromclothes

Solution / Approximate pH
Lemonjuice / 2.2–2.4
Tomatojuice / 4.1
Coffee / 4.4–5.5
Humansaliva / 6.5–7.5
Householdammonia / 12.0

A / B
Normal salt / NaCl
Acidsalt / NaHSO4
Basicsalt / Pb(OH)Cl
Doubleacid / Potashalum

Citrus fruits / Alkalinesoil
Rice / Acidicsoil
Sugarcane / Neutralsoil

Salt / Uses
CommonsaltNaCl / • inourdailyfood
• aspreservative
Washingsoda Na2CO3 / • usedinsofteninghardwater.
• cleaning agent fordomesticpurposes
BakingsodaNaHCO3 / • usedinmakingbakingpowder
• ingredientinantacid
Bleachingpowder
CaOCl2 / • disinfectingdrinkingwater
• bleachingcottonandlineninthetextileindustry
PlasterparisCaSO4.1/2
H2O / • forplasteringfracturedbones
• inmakingcastsforstatues

Chemical reactions

Model evaluation:-

1. Zn + 2HCl → ZnCl2 + H2 ↑

The above reaction is an example of Displacement reaction.

2. A reddish brown coloured element ‘X’ on heating in air, becomes a black coloured compound ‘Y’. X and Y are Cu and CuO .

3. A student tests the pH of pure water using a pH paper. It shows green colour. If apH paper is used after adding lemon juice to water he will observe redcolour .

4. Chemical volcano is an example of decomposition reaction.

5. When crystals of lead nitrate on heating strongly produces No2 gasand the colour of the gas isreddish brown.

6. When aqueous solution of silver nitrate and sodium chloride are mixed, white precipitate is immediately formed .

7. Aluminium can displace Zinc metal from aqueous solution of Zinc sulphate becausealuminium is more reactive than zinc.

8. To protect tooth decay, we are advised to brush our teeth regularly. The nature of thetooth paste commonly used is basic in nature.

9. Vinegar is present in acetic acid. Curd contains Lactic acid.

10.pH = - log10 [H+]. The pH of a solution containing hydrogen ion concentration of 0.001M

solution is 3 .

ADDITIONAL QUESTIONS

Physical changes can be easily reversed but chemical change cannot be reversed.
During chemical changenew substances are formed .
Chemical changes are more permanent than physical changes.
All chemical changes are accompanied by chemical reaction .
Silver and hydrogen sulphide in the air combine to form silver sulphide and hydrogen gas .
Lead nitrate and potassium iodide solution are colourless.

A deep yellow precipitate lead iodide. (PbI2).
Silver anklet lustrous white colour of the silver anklet slowly changes into slightly black colour (tarnished).
The substances taking part in the reaction are known as reactants..
The reaction which is formed after a chemical change in the reaction are known as products.

Calcium oxide (quick lime) reacts with water to form slaked lime(calcium hydroxide) and heat(bubbles)/ exothermic and hissing sound.
Slaked lime is used for white-washing.
Calcium hydroxide reacts slowly with carbon dioxide in air to form a calcium carbonate .
Chemical formula for marbleis also CaCO3.
A pinch of calcium carbonate powder and dilute hydrochloric acid to form Calcium chloride and carbondioxide(brisk effervescence).
A reaction in which a single product is formed from two or more reactantas is known as combination reaction.
Mg combines with oxygen to form magnesium di oxide.
Combustion of coal and Combustion of hydrogen are examples of combination reaction.
When copper carbonate is heated colour is changed from green to black.
Decomposition of lead nitrate into leadoxide, nitrogen dioxide( reddish brown gas) and oxygen.

Asinglecompound breaks down to produce two or more substances. Such typeof reaction is called decomposition reaction.
Examples for decomposition reaction

1. Decomposition of lime stone

2. Decomposition of ammoniumdichromate

Blue colour of the copper sulphatesolution changes into green colour.as iron is more reactive than copper.
Iron displaces copperfrom its salt (CuSO4)solution.
Copper is less reactive than zinc and lead.
The reaction, in which, a more reactiveelement displaces a less reactiveelement from its compound is calleddisplacement reaction.

A white insoluble substance in water is knownas precipitate.
Any reaction that produces a precipitate is called a precipitation

reaction.

Double Decomposition Reaction isthe reaction in which exchange of ionsbetween two reactants occurs, leading tothe formation of two different products.
A phenomena like fading of colours of clothes, burning of combustiblesubstances like cooking gas, wood and Coal,electroplating and extraction of Al and rusting of iron articles is due to oxidation and reduction (redox reaction.)
A chemical reaction which involves addition of oxygen or removal of hydrogen or loss of electron(s) is called Oxidation.
Addition of oxygen,removal of Hydrogen, loss of electron is known as Oxidation.
A chemical reaction which involves addition of hydrogen or removal of oxygen or gain of electron(s) is called Reduction.
Redox reaction is a chemical reaction in which oxidation and reduction take place simultaneously.
Oxidation also has damaging effects on food and eatables.
Oils and fats are slowly oxidized to form foul smelling compound.
The chemical reactions which take place with the evolution of heat energy are called exothermic reactions.
All combustion reactions are exothermicand heat energy is liberated as the reaction proceeds.
The chemical reactions which take place with the absorption of heat energy are called endothermic reactions.
The rate of chemical reaction is defined as the change in concentration of any one of the reactants or product per unit time.

Rate of the reaction is given by

d[A] d[B]

Rate = ------= + ------

dt dt

[A] - concentration of reactant A

[B] - concentration of product B

- ve sign indicates decrease in concentration of A with time.

+ve sign indicates increase in concentration of B with time.

Thenature of the reactant influencesthe rate of the reaction.
The greater the concentration of the reactant, the greater will be the rate of the reaction.

The increase in temperature increases the rate of the reaction .
The greater the surface area, the greater is the rate of the reaction.

The catalyst used in the decomposition of potassium chlorate is manganese dioxide.
A substance which alters the rate of reaction without undergoing any change in mass and composition is known as catalyst.
Bodymetabolism is carried out by means ofhydrochloric acid secreted in our stomach.
Acids have one or more replaceable hydrogen atoms.
The word 'acid' is derivedfrom the Latin name ‘acidus’ which meanssour taste.
A vigorous volcano is made using ammonium dichromate.
A silent volcano using baking soda .
Based on ACIDS sources are classified as organic acids and inorganic acids .
Acids present in plantsand animals (living things) are organicacids .
HCOOH, CH3COOH are examples of Weak acids..
Acids in rocks and minerals are inorganic acids or mineral

acids.

HCl, HNO3, H2SO4are examples of strong acids.
Based on Ionisation acids are classified as acids and weak acids.
Acids which ionise completely in water is called as strong acids.
.HCl is an example of strong acid.
Acids which ionise partially in water is called as weak acids.
CH3COOH is an example of weak acids.
Based on Concentration:- Concentrated Acid and dilute acid .
Acid having a high percentage of acid in itsaqueous solution is known as concentrated acid.
Acid having a low percentage of acid in its aqueous solution is known as dilute acid.
Tribasic acid.
Acid which gives one hydrogen ion per molecule ofthe acid in a solution is called as monobasic acid.
HCl, HNO3.are examples of monobasic acid.
Acid is an acid which givestwo hydrogen ions per molecule of the
acid in solution is known as dibasic acid.
H2SO4, H2CO3are examples of dibasic acid.
Acid is an acid which givesthree hydrogen ions per molecule of the acid in solution is called as tribasic acid.
H3PO4is an example of tribasic acid.

Apple contains Malic acid.
Lemoncontains Citric acid.
Grape contains Tartaric acid.
Tomato contains Oxalic acid
Vinegar (food preservative)contains Acetic acid.

Curd contains Lactic acid.
The acid must always be added slowly to water with constant stirring.
Basicity of acetic acid is monobasic..
Basicity refers to the number of replacable hydrogen atoms in one molecule of an acid.
Zinc reacts with dilute hydrochloric acid to form zinc chloride and hydrogen gas.

When a burning candle is brought neara bubble containing hydrogen gas ,the flame goes off with a popping sound.
Hydrogen gas burnswith a ‘popping’ sound.
Metal + Acid→ Salt + Hydrogen.
Metals do not liberate hydrogen gas on reaction with acid are silver and copper.
Lime stone, chalkand marble are different physical forms of calcium carbonate.
Calcium carbonate reacts with acids giving the corresponding salt, carbon dioxide and water.
When carbon dioxide is passed through lime water, it turns milky.
Metal carbonates and metal bicarbonates are basic in nature.
Metal oxides are basic in nature.
.Metallic oxide + Acid → Salt + Water
An acid produces hydrogen ions in water.
Hydrogen ions cannot exist alone.
When water is absent, the separationof hydrogen ions from an acid does notoccur.
Sulphuric acid (King of chemicals)is used in car batteries and in the preparation of many other compounds.
Nitric acid is used in the production ofammonium nitrate which is used as afertilizer in agriculture.
Hydrochloric acid is used as a cleansingagent in toilets.
Tartaric acid is a constituent of bakingpowder.
Salt of benzoic acid (sodium benzoate)is used in food preservation.
Carbonic acid is used in aerated drinks.
Planet venus is made up of white and yellowish clouds of sulphuric acid.
Metal carbonates and metal bicarbonates are basic, they react with acids to give salt and water with the liberation of carbon dioxide.
Depending on the percentage or amount of base dissolved in water, bases are classified as concentrated alkali and dilute alkali.
Concentrated Alkali is an alkali having a relatively high percentage ofalkali in its aqueous solution.
Dilute Alkali is an alkali having a relatively low percentage of alkali in its aqueous solution.
Base is a substance which releases hydroxide ions(OH-) when dissolved inwater.
Bases is bitter in taste and soapy touch .
Bases e.g. washing soda, caustic soda and caustic potash.
Bases change red litmus to blue.
Bases are pink with phenolphthalein and yellow with methyl 0range.
Strong Bases are bases which ionise completely in aqueous solutioneg.NaOH, KOH.
Weak Bases are bases which ionise partially in aqueous solution eg.NH4OH, Ca(OH)2.
Monoacidic Base is a base which ionises in water to give one hydroxide ionper molecule. e.g.NaOH, KOH.
Diacidic Base is a base which ionizes in water to give two hydroxide ions permolecule. e.g. Ca(OH)2, Mg(OH)2.
Triacidic Base is a base which ionizes in water to give three hydroxide ions permolecule. e.g. Al(OH)3, Fe(OH)3.
Acidity is used forbase, which means the number replaceable hydroxyl groups present in one molecule of a base.
Bases which dissolve in water are called alkalies.
All alkalies are bases, but not all bases are alkalis.
NaOH and KOH are alkalies, whereas Al(OH)3 and Zn(OH)2 are bases.
Bases turns red litmus paper blue .
Zinc reacts with sodium hydroxide toform sodium zincate with the liberation of hydrogen gas.
Metal + Base → Salt + Hydrogen
All metals do not react with sodium hydroxide, e.g. Cu, Ag, Cr.
Sodium hydroxide reacts with carbon dioxide and gives sodium carbonate and water.
Non metallic oxide + Base → Salt + Water
Bases generate hydroxide (OH-) ionswhen dissolved in water.
Reaction between an acid anda base is known as neutralisation reaction.
Acid + Base → Salt + Water
Sodium hydroxide is used in the manufacture of soap.
Calcium hydroxide is used in whitewashing buildings.
Magnesium hydroxide is used as a medicine for stomach disorder.
Ammonium hydroxide is used to remove grease strains from clothes.
Acidic nature decreases Basic nature increases in pH scale.
pH stands for the power of hydrogen ion concentration in a solution.
pH values decide whether a solution is acidic or basicor neutral.
pH scale was introduced by S.P.L.Sorenson.
pH is mathematically expressed as pH = -log10 [ H+ ]
The hydrogen ion concentration of a solution is 0.001M.The pH of theSolution is 3.

Indicator colour in acid colour in base