Consider the Reaction of Sodium Metal and Chlorine Gas to Produce Salt

lnformation: Sources of Error in the Real World When we perform experiments in the laboratory we never get all of the product we theoretically could get. Reactions in the laboratory are not ideal. For example, consider the гeaction of sodium metal and chlorine gas to produce salt: 2 Na + С12 .--- ➔ 2 NaCl � lf we react 23.0g of sodium metal with plenty of chlшine gas, calculations tel1 us that we should get about 58.5g of sodium chloгide. However, if you tгied this in the lab and then took the mass of your final product on а balance, you would usually get somewhat less than 58.5g. The more cш:eful you аге, the closer you can get to the mш:k of 58.5g, but you will never Ье аЫе to make 58.5g of sodium chlшide. . Critical Thinking Questions . 1. What are some pгactical things-some "souгces of error"-that сап happen ih. the lab and in а re�ction that woul� cause us to get less th�n 100% of the product that we are trying to • .• • • .. . ... . • • • '; _ , , . produce? srili/11.,. e,./I\R,�ic�/J1. ( t-i vм",,, ·.W'6i_Jh'i;,� ·, /(1_.�r.r-te,'+ly 1 -t. yYD )""') •.. • � ., The 1hfoгination section above.made it sound like we always would get less than 58.5 g of salt. Hьwever, it is possiЫe фаt afteг th,e гeaction we coL1ld take the mass of the pгoduct and find that it is gгеаtег than ,58.'5g. According to our calcL1lations this shoL1ld Ье impossiЫe, bL1t w.hat-."�oщ·ce� of е1т01·" may с;�шsе this? 1 : . м iJиi,.,.9 · ;;,, ц,rr-t.i+-f"1 � ... .vr1 d��- �·�-� ,, . , , ., . .• . ' • • J. ( и. vм �./'� ;- ) fi',11 '"-"!i. \ ' • f,: . . • ' ... ' 3. When 40.5 g of sodi.L1m metal гeacts with. 'plentY.·o(chlcн:iriё . . . . . gas,. how. many gгams of sodiL1m ,---chloride shoL1ld Ье prodL1ced? (Note: when qL1estions аге wot'd�d-this way, yoL1 aL1tomatically �hat sodil1m is the limiting гeactant.) М ai°S - f'Y111-� r_ !+о,•, k / 0,,_� ч 1.?. '. \ $j ,:-Ja )< • \ mo 1 /J°I( 7- ""о \ N-:CJ \( !?l. ss_, . .. • Z� -�С!.� • .' "2 • ft"O.\ (У�· ,.,�� . \ МО( (Va,C.,' =. •о з � 1 J\14C.I lnformation: Calculating Percent Yield Percent yield is а measure of how much of а product you actually obtained in а reaction compared to the amount that you could have obtained according to calculations. There is а handy formula for calculating percent yield: actual yield . percenty1eld=------•100 theoretica yield "Theшetical yield" is the amount of а product that we should Ье аЫе to make. Уou calculated the theoretical yield of sodium chloride in question 3; hopefully your answer was about 103g. Now let's say that you actually attempted this experiment in а lab with 40.5g of sodium and when you were finished you collected 84.0g of sodium chloride-this amount is your "actual yield", the amount of product you actually collected in the lab._ Using the formula given above, we сап calculate our percent yield: 84.0g . percent y1eld= --• 100 =81.6% 103g Critical Thinking Questions + I ОН 2 О Z..,C. � tf 1 +-130 L ---=> � С О 2.. 4. Considi:;.n�.Lon?bustion of 215.0g of butane, С4Н 1 0 with plenty of oxygen. If you are аЫе to с 295.Зg f water in the laboratory, what was your percent yield. Hint: first calculate your theore 1cal yield using the balanced equation and mole ratios ! t 45� с, � �•о х �.,,_С, И,с,. )( _, 10 r,,ot �.J.o'I(' ) f .о�� -\-{_ 1.? ::. � . 45·f. 1 'lj С&, Н, 0• 2. rмl С..., f.-1, 0 • • \ t"l'\O \ 4t1. () -z. J z: чs. 3 � )( ,оо • ;32..ct.5 ... L�<г.-+ "iJ Г"'°'"'' + �з Nо� __, АэG' +NtANos' 5. Consideг the douЫe i-eplacement гeaction of"104.7g of t_O ·um chloride with� of silver nitгate. If you ai-e аЫе to produce 150.4g of silvei- chlш. what was your pei-cent yield? (Hint: fii-st find_the limiting гeactant!) t ОЧ. :J�NaGI )( \ t'W'\� \ _ � .о'2.. � -=J, IV'O ( N4'LG( . �'3,q� er,tJOз � ,�·ч Ч мо\' tч,. t, �� �f-1°!. �tJ0 )(' .\. �\ 3 \t,Ц.-=J-� NAGl x 150 \мо\�4С..( )( '$ t5f,3SjNo.c.\ 4 � 100 � -�,.�s��d.(.\ • / \мо_\ �f.( "1( J_Lfз,'2..'5j_� 1 = 2s-=1-j А-1\С.,' \�olN.,.,C.\ fis y. s 0/01 (l""t\o�AtjC..\ ··-J 6. If you make 46:t;of calcium carb1mate Ьу reacfing 87 .5 g of calcium niti-ate with 98.бg of s, carbonate, what is your pe�c.er:t yi�ld; Co..(N�)"L + N�, С.0.3 _., СоС..0 +lNta.� . _ odium 3 •' •.• • � '�.+.�C,(f.J9s)i.:�L�olCй�){ \·�ot"4(0�� (oo.'•f, • -� S3.49 • ·I llЧ •• l c�coJ \ n\ьt ц-.,� t t'\\ о I G1.co l((p .t� Х /о() � з. 4 ,j 3 ::- (j-=1--. � c;Z>