Partial preview of the text
Download Chemistry handwritten notes and more Study notes Chemistry in PDF only on Docsity!
CHEMICAL REACTIONS AND EQuaTIONS CHEMICAL REACTION $- +A process In which new chemicalcs) ate gormed. + Hydvogen gas -veact with Oxygen gas to produce water under some condition. Hydwogen + Oxygen ————> cwoater CHEMican Eeuatfon $- stmple Representation of a chemical Reaction with symbols and fownula Ha(g) + 021g) ———> 2H 0() (Reactant) ( product) CHARCTERIsTics oF A CHEMICAL ‘- formation Temperature state sae or agae ‘hange charge _—— C (S) t Oa(gy-960219) exothermic enddhermic BALANCED CHEMICAL REACTION :— tn a chemical Equation should be the same as « Number of Atoms of each element LHS and RHS Ls BHS. Arg) + 821g)? 2B ig) ? ‘Corgenvation of mass Total mass of Reactant should be equal to total mass of products. . Firct Balance Metals 21, fe. Na, Al, Mg» Mn, cu, Ca,Pb. Ba « Second Balance Non-Metals Cl, Br, SNC - Third Balance oxygen then Hydrogen Buamplest- ( ZA + 2c] ————> _ZNCla +t Ha Q) afe + 4x0 -———————> fegdy t4Hs ) fes031 2Al ————> _ Alh0s tife (Y) Back + Aly(SOy)3 ——»36450y + 2Alcls (5) Pb(NOs)3—————3Pbo_ + 4NO2 *02 Types oF cHemicnn REACTION $= ty Combination Reaction $— Two or More veactant combine to form a single product. Ats ————— AB a 2M@gis) + 02193 7 2M (s) + Heat (White) (Exothemmic) Importarts points + = (Mg burns with Dazzling whiteglame ( Very Bright lignt) ty A white Mgo pocader in watch glass fale! Sree yeleases 0 a ecg increases . 4 xothermic Reactt (yyCombination and & 3,1 basaling whiteremelight fo Fox vIIE Mug’ im be ere en % = Calis) + Hr0(1) > Ca(OH); (aq) + Heat (Quicklime) (slaked lime) (@xothermia Importants points 3 —_qy Rise In temperature (exothermic) Quick lime veacts Vigovously with water. (a) water added slowly because Reaction fs exothermic . wauick lime used Tn nak cement. (6) combination and exothermic Reaction - Other Examples of Combination Renction 3 () Burning ofcoal - C(s) +0. ———» C029) Q) on of water prom Ha(q) and 02(q) 2H (q) + 02(q) > 201) Q) Decomposition Reachon_ += *Onceactant breaks [nto two or move product. AB ———___——> A+B HEAT Elechict LiowiT (Thermal) ( electr 1) ( Photochemical) Caco3is) —Heat___cao + corgy (.fmestone) (Quicklime) eused inmaking cement. (i) THERMAL DECOMPos am — —Heat__— fex0ai6) 4 50219) + $0a (@) ip Importantpofnts $- — «y Fersous sulphate crystals lose water and colour changes From pale green (Fesoy tH:0) to white (fesoy) on heating. Further heating decomposes FeSOy te fer03 ( Reddish- brown) (2 PHOIOCHEMIcAL DE@MPOSTTION ( Photolysis);— bveaks due to Ifght- a cies) ee t Claeg) ( Gisey) ¢ used In Black and White 2AgBris) —Sunlight __, (s) +Brs(q) Thisis phowree a. land . (qellew) ‘aon colour bate te pw Displacement Regction + one — element Replace a less Reactive element a form its compound- = aArac —> Acts Reactivity senes3- “= Gana Potassfum(k) kudi Moreveactive Sodium (Na) Naal Calcium (Ca) car esium (Mg) Mango Aluminium(Al) Alto Zinc (zn) ZISko tron (Fé! te teed Mae m Copper (Gu) chale Mewaury (Hq) = Silver (49) Gold (Au) Gahumne ww nls) t+ Cusoyl 4s — FE x fe(s) t CuS0y(aq)——>fes04 (aq) + Cuts) BI (Red/Grown) oR x An(s) + HaS0u(aq) ————> ZnS0y t Hat + Heat is colourless and odorless .bursn with popsound ons 3-1) H observations OOH AE xtinguishes burning candle. (Temperature Increases , yeacton ts highly exothewmic. acid is used as reaction is highly exothermic and (yD! conc. acid can lead ts more exothermic and dangerous réactton. oub nt s~ «exchange of fons between Reactants - de + co ——— AD tBc Na2S0y (aq) + Bacla (aq)——> Rasdyisi} + Nacl (colourless) (colourless) white ppt ations2—(obihite Insoluble substance (precipate) of Basoq 's formed. (i)Double Displacement and precipitation veaction. ueous sdluble - soluble solutfons Precipatio Frecipttation Renctions 3 When too, -yeact fo pom a semi soluble / tradluble salt, the salt is called precipitate and such veactton is precipitation Reactions. Ph(NOaly caqi #241 (aq) ———> Pb +2KNOz (Potassium yay rodide te Pie inwater) tn yellow frsoluble sukctance (precipale) of Pb i Formed (i) Double displacement and precipation veactron. Hear IN REACTIONS c- Exothermic R” Endothemmic R” Atg———>< t Heat q —Heat——»6 tc Examples (i) Resptration . Examples | | Cilucose t 02 —> COa t H20t Energy Al) Examples of Decompasition veacton. Q) Burning of natural gas. () FeSOuts)—Héat fe 303s) +502) F $03(q) @) emeadinn “ec (» Cacdais) —Hgat—»cadis) F co2(§) : orm ae pes f (3) Pb(Noaia s» —HEat»Pbors) + NOs«g) #0249) Ca0is) + ae (OHa); tHeat (see example of decomposition ¥”) | AND REDUCTION Reduction ait Pen ne cra 6 c Fyogen olf 9 chemical (8) ——>S1ains th eee x itis 7 cian ofipland(Ajis said itis called veduction of (G). and (B)is said TT. | 0 oe Aen. Culs) +02(q)—Heat—» cyt) tH cqptieat_» cu is) + H20 (reddishremaity —? t Black colow) (blackcolead (Brown) Redox Reactions The Reaction tn which oxidation and ReducHon occurs. x ing agent) —Zno0 + © ———— > 2 rco Trick + Jiska "eile Vn 6 ahd ecto PHYSICAL AND CHEMICAL CHANGE Physical change chemical change /No chemical Reactfon 7 chemical veactton happens. : phen 7 shape. size, colour.ete may also change. /shape, size state, etc May change. ty Bolling water pom thocrgunnge> (DRespr a Slee “a sce: Dp ot Po per cup. gycurd oon Lal (ocryetllisation (fermentation of grapes. (#) Burning of paper . 
