Question

Show all work to receive full credit. Express answers to the correct number of significant figures. Note: Complete the table below by calculating the initial SCN and equilibrium Fe(SCN)2+ concentrations for each of the five standard solutions. In addition to the volume of KSCN indicated in the table below each solution contains 5.00 mL of Fe(NO,)a and sufficient 0.050 M HNO3 to produce a total volume of 25.00 mL of solution. 1. Fe3+ +SCN Fe(SCN)2+ 0.00200 M Molarity of KSCN 0.200 M Molarity of Fe(NO3) Fe(SCN)2+ M Absorbance Vol. SCN Initial SCN M Solution 1.590 5.00 mL 1 1.320 4.00 mL 0.990 3.00 mL 0.690 2.00 mL 0.335 1.00 mL 5

Answer 1

The chemical equation of the reaction is shown below. - Fe3+ + SCÃ Fe Scrust2 . so Imole of Fet3 In reacts with indle of scñ Ion and forms I mole of Fe (SCN) at molarity of KSCN - 0.00200M KSON → Ktisch so the moority of sch' 000.om molarity of Fe(NO3)3 = 6.000m. volume of the solution of Fe (GCN) 7 = 25 mL 0.025L Every solution contain 5.00mL of Fe(NO3), so we can to calculate number of moles & molacity x volume in L. Number of moles 4 Fe(NO3)zin 5 mL = 0.200 m) x6.005 X=0 och - Number of moles of Fe(NO3)2 = 0.001 mots. - volume of Fe(NO3)3 is common to all solution. ② solution volume of ScNt 5 mL @ 0.0052 number of mides of sch's 6.00200 m/X0.005 Y = 0.0000l mols so limiting reagent is scn. Fest + scño x Fe (SON) + 2 conantialian Co.00 lmo) Cocooolmaty Co moles) Final (0.00099 moles) Co moles) (0.00001 moles) Concentration +2 Number of moles_ o.oooolnoles 0.0004m. so molocityg Fe Beru) volumes 0.025L Concentration of Fe(CN)2T 0.0004m. so based upon this number of moles of ScÑ' and Fe (SCN²t are same.

solutione volume of scÑ' solution - 4 mL 0 0.004h number of moles of scÑ' in 4 ml = molocityx volume=0.0020only ocal Numbord molus sco re Scutere same =0.000008 moles - volume of solution: 25.00mL @ 0.0052 molocity & Fesent Number of moes 0.000088 moles_ 0.00032 - volume 0.025L Initial concentration of schole number of moles - 000008 mble, 0.00032m. volume Cash saution 3 volutine of SCN solution - 3 mL 0003L Namber a moles of scn'm mL: 0.00200 m), X0-003L-0 Boccoudy Initial concentration & scn's Number andes 0.000006 mods 0.00024m - volume 0.025 L molarity of FeSONRt 0.000006 moles = 0.00024M 6.025 L solutions volume of ScN' solution - 2mL 6 0.002L Number of moles of scnt in aml = 0.00200 m / xo.0024 -0.000og And Initial concentration & SCN = 0.000006 mdo - 0.00016ML nolarity of FeSON)?t= 0.00000&moles - 0.00016 M solutions volume of SCN solution - 1 mL coll number a moles of scr'in ImL = 0.00200m (XO OOK=0.00000QM Initial concentration & scn'- ooooogmiles_ 0.00008m motocity of FelsNiet 0 000002 indo 252 = 0.00008 m 0.025L 0.025 L 0025

solution G I Wp- volusÑl Initial Sci'm 5.00mL 0.0004m 4.comL 0.00032m 3.com 6. 00024M 2.comL 0.00016 M 100 ml 0.00008 m Fe (SCN)²TM 0.0004m 0.00032m. 0.00024M o.ooo 16M 0.00008 m.