Question

Muyuulin (1JJ. Part III: Determination of a Solubility Product In Part Ill you will prepare a saturated solution of silver carbonate (Ag2CO3) and deten solubility product constant of Ag2CO3. Ag2CO3(s) = 2 Agt(aq) + CO32-(aq) (17) In making the solution, 1.0 mL of 0.10 mol/L AgNO3 will be added to specified volume mol/L Na2CO3. The limiting reagent in this reaction will be the silver ions. Use of an excess an of anion allows for a relatively simple calculation of the anion concentration after reaction using the stoichiometry of the reaction and the amounts of reagents mixed together. Assuming that most of the silver nitrate reacts, the concentration of silver ions after reaction is very small ( 0). Using Ag+(1.00 mol/L)Ag(s) as the reference half-cell, the cell potential is measured. The equilibrium (Agt) in the silver carbonate solution is calculated using the Nernst equation and an ICE table used to determine the equilibrium concentrations. The error in the determined value for the silver ion concentration will depend on the error in measuring Ecell, which will be much larger than the error in measuring the volume of Na2CO3. The measurement of Ecell will therefore determine the error in the calculated value of Ksp. Side View Top View 000 0.010 M 0.10 M Ag Ag 1.0M KNO, 0.0010 M Ag 1.OM 1.0 M Ag Cu2+ 0.00010 M Agt Silver metal strip Silver metal strip 1.0M KNO Ag, CO, Ag (aq) x mol/L Ag (aq) 1.00 mol/L KNO

Answer 1

Voltmeter Page - Ag metal I trip satt age r e og nooit la A (cathode) Agt (ag) = Indell El Cance) KNO3 Agt (emolelL (saturated Soletion of mixing Na coz & saturated of ime of sorution solution es or IM No Acoz is solution and prepared by and of im or IM Noz socction TAGNOZ = 2 zmesm (Final V. Cone. 2x0.025 Hence the concentration of Agiloz and Has Coz after mixing (s. e bebore reaction ) [AgNO3) = l'mexo.im [na Con = 1 maxim 2005m. (Final Volume i ane / of solution 2 AgNoz & Haloz - Ag2(031 +2Nanoz Initial 0.05m 0.5m PPE or o change o rois = 0.025m Final conch & (0.5 -0.025 = 0.475m Reagent, hence completely Here AgNO3 is limiting excess. used during reaction and Nazloz is exe Hence the concentration of [6627 - 0-475m (7) Now the call reaction of the above concentration cell is at cathode Agt te O المة هما ا Ag(s) n=1 (nomber of (IM) 3 м electron at anode 1 Agt te transfer=) notam Anm) Ecen according to Nernst equation is Eren - Ecen - 2.30 3 R T log Qe where Ragas Constant T= 2985 a = 8.3145lking Feen=0.35V) E cen - standard emt =0 because of Q-Reaction quotient : Concentration Coll. = number of electron transber NF T= 298K F=96500 coulomb

4 Ecos ou 2303 x63418298 log [Agt Janode page 1496500 & Eccy = – 0.8591 log ytJanode Fligt Cathode [Asty Cathode log [Agtanoda. – – Ecen = + 0. 3500 0.0591 Ag ty Cathide 0.0591 log Ingt Jande _ -6 a log ng lande -6 [Agts cathode log [Agt Janode =-6 - [Agth anode 10 om Alance [Agty in test solution of anode = 100m The equilibrium concentration of [102 27 after reaction = 0.475m (See page ) Now we Find Ksp of Ag, 103 Ag203 (s, zagt & Co? Ksp = [ngty (202-7=(18-672(0.4757 - 101 1270 475 Tu=4.75 +1013 Hence Ksp of Age Coz = 4. 78-710-13 4