## Question

###### To prepare the Iest solution, 50 mL vo umotric flask add 50 mL 100 mgi Fes+ solution from Ihe 10 mL buretto. With the provided abelled, glass pipette, add 00 mL of 2000 M KSCN solutlon: Miix well and add mL; using auto-dispenser of Mnitric acid. Make the solution up to Ihe 50 mL mark , slopper Ine flask and mlx well. Note that the concenfrarion [hocyanale colutio n the fest solulion only comdared Kith for the standards; comiete converrian tno comolox doos not occur Calculate the concentrations

To prepare the Iest solution, 50 mL vo umotric flask add 50 mL 100 mgi Fes+ solution from Ihe 10 mL buretto. With the provided abelled, glass pipette, add 00 mL of 2000 M KSCN solutlon: Miix well and add mL; using auto-dispenser of Mnitric acid. Make the solution up to Ihe 50 mL mark , slopper Ine flask and mlx well. Note that the concenfrarion [hocyanale colutio n the fest solulion only comdared Kith for the standards; comiete converrian tno comolox doos not occur Calculate the concentrations of Fe * and Fe(NCSY- your propared solutions and wnte them in the relevant column the table on tho noxt page. Calculation of [Fo" ] concontration the standard solutions: Start by vorking out the molar concenbalion oltho 100 mG/L ("'stock ) Ircn solution You used make Incm Up_ mgIL Moll [Fe" ] stock solulion Now calculate Ihe concentraton (n M) = pacn dilution using the equation: M,V MzVz Which can rearrangud produce the equation for the quanbty we want: Mz(Vz / Va) whare: is Ine concentrallon 0f Foj" In the fInal solution, Va [s the volurne of the Fel final solumion tne volume of tho volumetnic flask; this case 50&L thu volume Ihe sock solution you added the flask (in mL) molanIFe concentraton Ihe stock soluton from YOUt calculatlon above Anannernin crocenon Lade Irie Odulion ratlo long e3 ;oJ use Urr corllertiona Iud boln volumus aucn Fcu Klarunno concuntratiom Tnaetandurusolubons: Calculatlon = [Fe(Ncs)" ] havu added excust thlocyanate. tume (hu complo A4CluSt Llmtosllcomdelely Iherprdicleidu lormallcn #quilibnum Ine Fe NCSk' tha elandard tolulions naranand concuntration Reumud oquivatent t0 thu concaniralion