Question

Please help!! with question (18 ,19, 20 )

the data is coming directly from professor and i think she made a mistake because after I work out problem I get theoritcal yeild of 0.850 grams

CaCO3 but the experiment actual yield is 8.322 grams (work out question 12 )

Carbonate LI General Chemistry Lab I H.Y. & S.D. ame ata Sheet Section Date • Precipitating Cacos 1) Volume of Na2CO3, mL 8.22mL or 0.00824 2) Molarity of Na2CO3 solution, mol/L 1.04m 3) Color of Na2CO: solution clear 4) Volume of CaCl2, mL 8.41 mb or 0.0084.L 1.22 5) Molarity of CaCl2, solution, mol/L 6) Color of CaCl solution clear 7) Step d) observations white precipitate began to form Filtering CaCO3 8) Mass of filter paper, g -3.04. 0.929 g -2.11g 12.9629 9) Mass of watch glass, g 10) Mass of filter paper + Mass of watch glass before drying. 8 11) Mass of filter paper + Mass of watch glass after 11.3629 A 1.69 'drying, & product - 13.04g) = H . 12) Mass of CaCO3,8 - white residue on filter paper 13) Step I) observations filtrate is clear lost some residue ne o if cloudy - you in filtration process. CaCO3 out Page 7 of 12 of beaker lose slose Coor

Answer 1

Cac + Nag coz limiting > Cacozt 2 nad Molanty of Na, log = 1.04M means 1004 moles in I leter of 1000 ml present so. 8.22 ml there would be - 8.22 x mots 1.04 (ODO = 0.0085483 = 0.0085 moles. There is I stoochimetry in reaction that means 0.00 85 moles of Caro will formed 18 . of product theoretical gield = Reactent used in goanas x Male adorengo molecular weight of Reactant But here we have moles so need to have molecular weight of cacos only CaCO3 = 100.666 geams / mole means. | mole of Ca Coz aim Joo - 0% 6 калид 0.0085 mole of cacor will have 100°08* 0.0085gen = 0850gm Theoretical grold = 0.850gn

S 19 Actual gield (mass of filles paper + Mass of watch glans ele stes, doyning) = minus (mass of filler papes y mass of watch glass of the 2 6 gou o 11.362 gus a 20:929 -2.111gm 1. = 8.322 gens Actud UUUUUUUUUUUUUUUUUUUUU greld = D . 8.322 guns s e po gield = the tuned yieldxlvo 17 Experimental gield 100%. 83 22 gms yoof impossible 0.850gu. either of clearly it is an experimental mistake. Most probably is that er them D-30 aris wrong. you haven't dried your sample completely. It is wet, that's why mass is shouting