Le Balancement D Équations Chimiques

solely for classroom use w ith O bservatory. 1. Balancing chemical equations 15 ACTIVITY ofYearTwoSecondary Cycle Second activities – Support Name: Observatory / b) a) someuse once. may words more than groupsofbox You the words words or in the below. sentences, using the following Complete d) c) • • • • • • • • • • 11129-B counting colour coefficient chemical chemical check propertiescharacteristic bonds balance small possibleas ______Guide A physical change occurs when the or occurs the formthe when physical change A changes and chemical matter: of three changes types in are There form ______A ______involves transformation same This the longer the afterchange. no are a of A same. The the remain the of the ice, form isinor liquid formin water Whether it ice. becomes water when example, is cooled, liquid For is changed. substance ______

substance. The very nature of of the The very nature substance.

______ANSWER KEY ANSWER ANSWERKEY

equation rearranging nucleus chemical nuclear new elements new Support activitiesSecond – Support Two of SecondaryYear Cycle ______• • • • • • • • • characteristic properties molar mass molar ofreactants mass ofproducts mass mass of conservationof law increase heat equal different decrease of the atom. The transformation causes the atoms to splitand the causes Theatoms to transformationthe atom. of new molecules. forming atoms and bondsbetween the the transformation involves changes that occur in the inthe changesinvolvesthatoccur transformation change alters the change nuclear . ______1 ______Group: Group: ______molecules ______• • • • • • • • • • precipitate physical nucleus nuclear new elements never nature molecules proportions products of water do not change. change. water not do of changes. ______15 113 RELATED RELATED HANDOUT physical STUDENT STUDENT molecules state nature BOOK: Date: is altered: they they is altered: Balancing chemical Balancingchemical equations • • • • • • • • • • EST Chapter 4, pages108– 4, Chapter : subscript stoichiometry state signs rules ofgas a release rearranging quantities whole numbers whole transformed ______changes, changes, that form waterthatform Concept review Concept of of a symbols

ACTIVITY 15 © E R P I Reproduction and adaptation perm itted

solely for classroom use w ith O bservatory. Name: Observatory / i) i) h) g) f) e) j) j) 11129-B

______Guide To follow the law of conservation of mass, we must of mass,we must of the conservation followlawTo to chemicalthe is equal reaction the ______the explainsthat famous statement this de made Laurent Lavoisier Antoine The scientist with solution) the identify ______a by represented or reaction, be can change,chemical chemical A ______of absorption ______place certain by taken change has chemical recognize a canthat We ______ofreactants quantities characteristic are whose properties brokenformare to new substances) occur the when Chemical changes the equation by comparing the number of atoms of each element on side. either on atomsof element number each of comparing equation the by the ______inSubscriptschemicalmust formulas existing removed. substances nor added, ______. coefficients be must The equation. Certain is equation side atomseach of onthe of ______The appropriate equation. side of the the onproducts and side reactants by equations ______law of law conservation of mass ANSWER KEY ANSWER as smallas possible as chemical equation chemical colour ______transformed coefficient coefficient increase ______signs never ______rules subscriptsymbols Support activitiesSecond – Support Two of SecondaryYear Cycle ______state counting counting heat

. to is useful took It place. how the change shows , which , : . must be placed in front of each substance so that the number thatthe so of substance each infront placed be must be changed. Finally, we must Finally, changed. be " This means that the the that means" This New substances mustsubstances New and the and the : : decrease

" ______Nothing is lost; nothing is created; everthing iseverthingiscreated; islost; nothing Nothing ______must be followed when balancing a chemical a followedwhen mustbe balancing formation ofa formation ______of the substances (solid, liquid, or gasaqueous liquid, (solid, the substances of 2 release ofa release gas whole whole numbers the number of atoms of each element on the on atomsof element number each of the , the emission of light, a change change in a of ,the light, emission in parentheses to the right of the substance. substance. of tothe parenthesesthe right in mass of products different bonds bonds products Group: Group: ______equal equal , and the quantities of products products the quantities of , and ______mass of reactants ______balance balance precipitate , the emission oremission , the , and theymustbe , and between reactants (initial (initial between reactants . During this process, the the this .During process, never never (final substances), (final substances), after the reaction. reaction. the after Date: Balancing chemical Balancingchemical equations . ______check check

chemical ACTIVITY before before .

be be 15

solely for classroom use w ith O bservatory. 2. Name: 4. 3. Observatory / j) i) h) g) f) e) d) c) b) a) What kind of change is described by each of the following examples?isdescribed of eachthe bykind of change What k) Aluminum oxygen and(O (Al) oxide calledcommonly(AlO), Aluminum arepresentsituation. the formula following chemical Write to d) c) b) a) occurring. radium radiation emitting radium inwater dissolving salt mercury that expands in hot inhot weather expands mercury that 11129-B rusting ironrusting food being transformed into energybeing into transformed food ofuraniumnucleus athe fission turns whitelimewater that

______the fusion of the nuclei of nuclei several atoms of fusionthe the thattarnishesbracelet a worntire a 2 Al 2 Guide reaction. We can use We use can reaction. the to maintain essential ofproducts. quantities ______A bright light appears when a piece of magnesium isburned. piece aof magnesium light when appears bright A ismixed withacid.when hydrochloricform chalk Bubbles ismixedwith NaI Pb(NO when yellow appears A substance match burns. A The emission The of light release gasThe of a change Ain and of coloura the formation precipitate For each of the following examples, name at least one sign that a chemical changeis chemical sign aone that least name examples, the followingat For of each The ofheatand emission light EST (s) When a chemical equation is properly balanced, we can find the the wefindcan equation is properly balanced, chemical a When ANSWER KEY ANSWER + quantities quantities

oxygen 2 ). Balance the equation. the Balance ). O

2 (g) Support activitiesSecond – Support Two of SecondaryYear Cycle ______ of reactants needed for a reaction and predict the the resulting predictand reaction needed areactantsfor of Stoichiometry molar mass molar proportions proportions alumina, 2 AlO 3 chemical change chemical transformation nuclear A changechemical A changechemical A physical change A A nuclear transformation nuclear A physical change A changechemical A transformation nuclear A physical change A is formed by the reaction betweenreaction the by is formed (s) Group: Group: aluminum oxide to convert molesinto to grams. convert is the study of these proportions. It is proportions. It of these isthe study ______of the substances throughout throughout the substances of the 3 ) 2 . Date: Balancing chemical Balancingchemical equations ______aluminum aluminum ACTIVITY A 15 © E R P I Reproduction and adaptation perm itted

solely for classroom use w ith O bservatory. 2 C

5. Name: 6. 2 C 2 Al 4 Observatory / (s) (s) c) b) a) reaction. in involved the molecule each of indicatingatoms in the bynumber chemical the following equations of each Balance If you obtainyou If following by equation:copper isrepresented the 10 oxide of g of The decomposition (s) + H 4 + + 3 + Cl x x g g 8 10 += oftheproducts.massmassTherefore,the be:of oxygen must the of conservationmass, ofreactants follow thetotal must mass Tolaw be equal to the total 11129-B O 2 + 2 C + CH 2 4 C C

C C Al Al Al Al ______= 2 = g 10 – g = g 8 Guide C Al C C Al C 2 CuO2 2 C + CCL 2 3 (s) (s) (s) (s) (s) (s) + H + 2(g) + O + + 2(g) 3(g) 4 Al + 4 2O Al H H H H

ANSWER KEY ANSWER Cl Cl Cl Cl O + O + 2 2 2 + H +  2 (s) 2(g) 2 2 2 2(g) 2(g) Cl+ H + 2 2 2 2 2 2 (g)

+ O + 2 Al  8 g of copper, what amount of oxygen was released? Explain your answer. 2(g) + x + H + 2(g)  2(g) 2 Cu2

2 O O  + H + 2(g) 2 H

 2 2(g) 3 Al 2(g) O + 2 2 2 CH + H +

CHCl2 3(s) O 2 O 2 (s) 2(g) + O + 3(s) 2(g) 3  OH

Support activitiesSecond – Support Two of SecondaryYear Cycle 

2(g) 3(g) CH (g)

3 OH Al Al Al C C 3(g) (g) C C Al Al Al H H H H Cl Cl Cl  H H H H 

O O     4 Cl Cl Cl O O O Group: Group: O H H O O ______

2 CH CH CH CHCl CHCl Al Al 2 2 O O 3 3 OH OH 3 3 3 OH 3 3 Al Date: CHCl Balancing chemical Balancingchemical equations 2 O 2 CHCl2 2 Al 3 (g) ______3 (g) CH 2 O 3 OH 3 3 (g) ACTIVITY 15 © E R P I Reproduction and adaptation perm itted

solely for classroom use w ith O bservatory. 7. Name: 8. Observatory /

EST Zn Zn HCl EST 10 mol 10 11129-B ______HCl HCl HCl HCl HCl HCl HCl HCl (s) 215.74 215.74 g (s) Guide Zn sufficient carbon? (The equation is not balanced.) equation (Theis not carbon? sufficient will 32of if formedglucose make What bemass you balanced.) silverequation (Theis not reactnitrate.with sufficient youmake silver produced if10 of moles of the and number Calculatethe mass + AgNO+ (l) + AgNO+ HCl C + 1 Zn + 2 + AgNOZn 65.39g 10 mol10 mol10 mol 1 mol 1 mol 16 HCl + HClC 16 10  1 ANSWER KEY ANSWER (l) (s) 2 AgNO AgNO HCl HCl HCl HCl HCl HCl HCl HCl Zn mol

  1 mol1 mo 3(aq) 10 3(aq) C + l 3 3 mo 10

 = mol20 = H C C C C C C C C l C 3 Ag 16(aq) + (s) (s) + Cl+ = 2157.4g = + Zn(NO+ C C Support activitiesSecond – Support Two of SecondaryYear Cycle 2(g) 339.76g 2 AgNO 2 O O Zn 2 mol2 3 H H H H H H H H ) 2 3 H H H H H H H H Ag Ag Cl Cl Cl Cl Cl Cl Cl Cl 

→   5

Cl Cl Cl Cl Cl Cl Cl Cl

Group: Group: N N C C C C C C C C O O

215.74g 215.74g mol ofacidmolreacthydrochloricwith ______

2 mol2 2 mol2 ? mol? C C

2 Ag 2 ? g ? O O

Cl Cl Cl C 10 C 2 2 2 Ag Ag Ag H 10 Date: 16 H + C 2 Ag + Ag 2 Zn(NO+ Balancing chemical Balancingchemical equations 16(aq) Ag 10 ______H (s) Zn(NO Cl Cl Cl Cl 16 + Zn(NO+ 2 2 2 2 + 8 + Cl 189.41 189.41 g + +

1 mol 3

) mol of mol zinc 2 Cl 2 ACTIVITY Cl 3 3 2 ) ) 2 2 2(g) (NO 3 ) 15 2

solely for classroom use w ith O bservatory. 10. 9. Name: Observatory /

How many moles of hydrogen are needed to produce50 needed to hydrogenare many How moles of How many moles of hydrogen will be produced by the complete reaction ofreaction75complete hydrogenthe will many produced by be How moles of EST EST 11129-B ______75 Guide 3 mol 3 2 Na2 equation:the Givenfollowing synthesisof ammonia: the the for Givenreaction 136 g 45.98 45.98 g 17.04 17.04

 583.36g 16 45.98 45.98 g 45.98 g 32 mol 16 mol 16 mol mol 1 (s) ANSWER KEY ANSWER 2 mol2  75 g 2 Na 2  + 2 + H 50 mol g 32 g 14.01 14.01 g N 1 mol1 g (s) 2(g) mo

2 O l = 1.63 mol= N (l) = 8.8 mol=

2(g)  + 3 + H 2 NaOH 2 = 272.52g = + + Support activitiesSecond – Support Two of SecondaryYear Cycle 2(g) +

 (aq) 36.04 36.04 g 120.1 g 10 mol 2 H 2 2 mol2 2 NH2 + H + 2 O 2(g) (l) 3(g)

3 mol3 3 mol3 ? mol? 3 H 3 6  2(g)

Group: Group: 136.26 136.26 g 136.26 g 2 NaOH2 2 mol2

1 mol1 ______80 g g of of ammonia?g

? g ?  (aq) + Date: Balancing chemical Balancingchemical equations ______17.04 17.04 g 17.04 17.04 g 2 mol2 50 g

g ofgsodium? 567.2g 2.02g

1 mol1 mol1 8 mol8 ? mol? NH 2 H 2(g) ACTIVITY 3(g) 15