Experiment Cyclic Voltammetry

Experiment – ELECTROCHEMICAL ANALYSIS OF FERRICYANIDE USING CYCLIC VOLTAMMETRY 2013-19846; 2013-67188 November 17, 2016 I.

Abstract Cyclic voltammetry is classified as a type of potentiodynamic electroanalytical  technique used for the study of electroactive species and is extensively utilized in industrial applications and academic research laboratories. In this experiment, the formal reduction reduction potential potential of ferricyanide ferricyanide was determin determined ed to be 0.21! 0.21! "  while in contrast, the theoretical formal reduction potential is 0.# ". $he effect of  scan rate and concentration on pea% current was observed. &ea% current was determined to be directly proportional to both the square root of scan rate 'v  1(2  ) and concent concentrati ration. on. *sin+ *sin+ two standard standard curves curves of Ip ox and Ip red a+ainst  a+ainst  concentration, the concentration of the un%nown was obtained usin+ the linear  mM  equations. $he concentration of the un%nown was determined to be 7.55 . II. Keywords: Keywords: Formal e!"#tion $otential, %#an ate, &no!i# $ea' ("rrent, (at)o!i# $ea' III. Introduction (*#li# voltammetr* i+ a i!el* "+e! te#)n te#)ni" i"e e in or!er or!er to a#" a#"ire ire "ali "alitat tative ive in.o in.orm rmat atio ion n abo" abo"tt t)e t)e ele# ele#tr tro# o#)e )emi mi#a #all rea#tion+ o##"rrin/ ar!  Fa"l'ner, 2008 5t /ive+ a "i#' lo#ation o. re!ox potential+ o. t)e t)e +pe#ie +pe#ie+ + .o"n .o"n! ! to be ele#tr ele#troa oa#ti #tive ve ar!  Fa"l'ner, 2008  & (*#li# voltammeter voltammeter #on+i+t o.  t)ree main part+ namel* a or'i r'in/ ele# ele#tr tro! o!e, e, a re.e re.ere ren# n#e e ele# ele#tr tro! o!e e an! an! a #o"nter ele#tro!e ar!  Fa"l'ner, 2008  & rever+ible ele#tro#)emi#al ele#tro#)emi#al rea#tion t)e #*#l #*#li# i# volt voltam amme metr* tr* pro! pro!"# "#e+ e+ )ave )ave ell ell !e.ine! #)ara#teri+ti#+ +"#) a+ t)e ratio o.  t)e pea' #"rrent+ i+ e"al to one, )e pea' #"rrent+ are proportional to t)e +"are root o. t)e +#an rate, an! )e po+ition+ o. pea' volta/e !o not alter a+ a ."n#tion o. volta/e +#an rate niver+it* o. (ambri!/e, 201 )e +t"!* +t"!* aim+ aim+ to #reate #reate a #*#li# #*#li# voltammetr* in or!er to t)e .ormal re!"#tion poten potentia tiall E0 o. t)e Fe Fe555( 55(N N 6 3- < 4Fe55(N 6 #o" #o"plin lin/, to !e.in .ine t)e t)e #on+e"en#e+ o. +#an rate an! #on# #on#en entr trat atio ion n vari varian antt o. = 3Fe(N6 on pea' #"rrent, an! to "anti.* t)e #on# #on#en entr trat atio ion n o. "n'n "n'no on n = 3Fe(N 6 +ol"tion Ele#tro#)emi+tr* - (*#li# Coltammetr* $a/e 1

:Fe0(N38;3- > e-

:Fe0(N36;4-

IV. Experimental  . -toc% &reparation &reparation %to#' %ol"tion  & 16462 / o. = 3Fe(N6 a+ !il" !il"te te! ! it) it) 01? 01? @NA @NA 3 in a 100 ml vol"metri# .la+' in or!er to prepare 0 m? =3Fe(N6 +to#' +ol"tion Beterminin/ t)e Formal e!"#tion $otential an! t)e e..e#t o. %#an ate  &n ali"ot o. 4 ml o. t)e +to#' +ol"tion a+ !il"te! in a 0 ml vol"metri# .la+' in or!er to prepare a 4 m? = 3Fe(N6 +ol"tion Beterminin/ t)e E..e#t o. Car*in/ %#an ate an! (on#entration  & var*in/ #on#entration #on#entration o.  =3Fe(N6 a+ prepare! in 0 ml vol"metri# .la+' at #on#entration+ o. 2,4,6, 8, 10 m? o. = 3Fe(N6 +ol"tion +ol"tion !il"te! !il"te! it) 01? @NA 3

)e +tep+ .or .ormal re!"#tion $otential a+ repeate! at var*in/ +#an rate o. 0, 100, 160, an! 200 mC