CHEM LAB 5 - Precipitation reactions and the synthesis of chalk chemistry lab PDF

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Precipitation reactions and the synthesis of chalk chemistry lab...

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Lab 5:Precipitation Reactions and the synthesis of chalk

Purpose: Purpose is to the show groups 1A and 2A ions reactions forming precipitation reactions and apart from that, showing the net ionic equations from these reactions. Procedure: Procedures are shown on pages 50-52 in “General Chemistry 110 Lab Manual” Data table: *Shown on last page Calculations Pre Lab: 1.) 0.200g CaCO3 (1mol CaCO/100.0.869g CaCO3)(1mol Na2CO3/1 mol CaCO3)(105.9888g CaCO3/1 mol Na2CO3)=0.212g Na2CO3 2.) 0.200g CaCO3 (1mol CaCO3/100.0869g CaCO3)(1mol Na2CO3/1 mol CaCO3)(147.01g CaCl2●2H2O)=0.294g Na2CO3 Theoretical yield: 0.214g Na2CO3(1mol Na2CO3/105.988g Na2CO3)(1mol CaCO3/1mol Na2CO3)(100.0869g CaCO3/1mol CaCO3)= 0.202g CaCO3 0.302g CaCl2 ● 2H2O(1mol CaCl2● 2H20/147.01g CaCl2● 2H20)(1mol CaCO3/1mol CaCl2 ● 2H2O) (100.0869g CaCO3/1mol CaCO3)=0.206g CaCO3 Na2CO3 is the limiting reagent Theoretical yield is therefore 0.202g CaCO3

Percentage yield: Actual yield divided by Theoretical: 47.409-47.238=0.717g

0.171 =0.847 → x 100 =84.7 % 0.202

Summary of results: Everything aqueous unless mentioned otherwise. 1.) CaCl2+NaC2H3O2 No reaction 2.) CaCl2+2NaOHCa(OH)2(s)+2NaCl Ca^2+2OH^(-1)Ca(OH)2(s)

3.) CaCl2+Na2CO3CaCO3(s)+2NaCl Ca^2+2CO3^(-2)CaCO3(s) 4.) 3CaCl2+2Na3PO4Ca3(PO4)2(s)+6NaCl 3Ca^2+2PO4Ca3(PO4)2(s) 5.) CaCl2+Na2PO4No reaction 6.) BaCl2+2NaC2H3O2No reaction 7.) BaCl2+2NaOHBa(OH)2+2NaCl Ba^2+2OH^(-1)Ba(OH)2(s) 8.) BaCl2+Na2CO3BaCO3(s)+2NaCl Ba^2+CO3^2BaCO3(s) 9.) 2Na3PO4+3BaCl2Ba3(PO4)2(s)+6NaCl 3Ba^2+2PO4^3Ba3(PO4)2(s) 10.)BaCl2+Na2SO4BaSO4(s)+2NaCl Ba^2+SO4^2Ba(SO4)(s) 11.)AlCl3+NaC2H3O2No reaction 12.)AlCl3+3NaOHAl(OH)3(s)+3NaCl Al^3+3OH^(-1)Al(OH)3(s) 13.)2AlCl3+3Na2CO3Al2(CO3)3(s)+6NaCl 2Al^3+3CO3^2Al2(CO3)3(s) 14.)AlCl3+Na3PO4Al(PO4)(s)+3NaCl Al^3+PO4^2Al(PO4)(s) 15.)AlCl3+Na2SO4No reaction Table 1 Unknown # Identity of Unknown

8 Aluminium Chloride

Part 2. Table 2 Mass of CaCO3 (g) Theoretical Yield of CaCO3 (g) % Yield of CaCO3

0.171 0.202 84.7

Conclusion: The 15 chemical and net ionic equations were determined therefore the purpose fulfilled. 10 out of 15 chemical equations had a reaction.

Alumiunium chloride reacted with sodium hydroxide; carbonate; phosphate but not with sodium acetate and sodium sulfate. Barium chloride reacted with sodium hydroxide; carbonate; phosphate; sulfate but not with sodium acetate. Calcium chloride reacted with sodium hydroxide; carbonate; phosphate but not with sodium acetate and sodium sulfate. My given unknown number 8 reacted with sodium hydroxide; carbonate; phosphate but not with sodium acetate and sodium sulfate. Part 2 of the report shows the calculation of the theoretical yield, resulting in 0.202g from 0.214g of sodium carbonate and 0.302g of calcium chloride dihydrate. The Actual Yield of 0.717g was calculated by the difference of [(filter+watch glass)+calcium carbonate] and just [(filter+watch glass)]. The resulting percentage yield was therefore 84.7%. The unknown number 8 is Aluminium chloride for the reason being because it reacted the same way as aluminium chloride. The second part of the lab showed that the reaction had a very strong yield, meaning the results are close and therefore accurate. Possible errors could have been confusion with the solutions, causing faulty results because of different mixtures. Apart from that the typical wrong measurement of precipitate that could have caused a different calcium carbonate mass.

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Precipitation Reactions

NaC2H3O2 No

Yes

NaOH

Na2CO3 Yes

Na3PO4 Yes

Na2SO4 No

No

Yes

Yes

Yes

Yes

No

Yes

Yes

Yes

No

CaCl2

BaCl2

AlCl3

Synthesis of Chalk, CaCO3

Mass of Na2CO3 Mass of CaCl2·2H2O Mass of filter paper and watch glass Mass of filter paper, watch glass, and CaCO3 Mass of CaCO3

0.214 g 0.302 g 47.238 g 47.409 g 0.171g...