> e-ps Chemisrqy 3: SOME INVESTIGA'TIONS INTO TI-IE CORROSION OF IIION Ptocedure: Part I. Reaction of Iron wirlr Variorrs Aqueous Ileagents a' Place a cleatt, bright nail in each of the nl.i.*r rrrbe.s. .slicle each 'ail care{rrlly down the side to avoid breaking the botton, oft,ir. tesr rube. b. Partially fill eacrr of trre rc.rr rub"*s *irh ;;.';i rn. r"rr"*i,if ,.rg",,,s s. thrt rhe nail is just covered. Your teacher will ,.iLyou which ;. ;i1i,;;rorrps ro use. Allsolutions are 0.lM. KOI"I HNO c' Determine the approxitnate hydrogen iorr corrcenrration o[:eac6 .solution using litmus pape'; Flydrion-papei or otrrer iiiai.r.o, soruriorrs. It is sufficient to recotd siilrply *liutir.ith. r;il;; is acidic, basic, or neurral. Go on to part II. d' Allow the nails t'sta.nd overnight in the solutions. observe and recor4 any changes thar have taken place.-(..omparc 1rou,. ,.r,rtrs rvitlr rhose of s...rcle rrrs using the_1ther sets oFreagenrs. Recorcr d-,.i,1 ,=rrrrr rro,,f *iirr,-r",,*;" tabular fornr. e' After the soltrtiotrs have stoocl nvernigh_t, arld o'c or rwo clr.trrs ,:F0.11.4 . potassiunr fbrricya'ide, KFc(CN)., i"l,;.1, conrai^$ rhe ir:rrr.s l(, ;r.cf ^ f"J9N)0."', to each solution ,n,l o'dse*. ,r;r,-l,r,,g*. f' Add one 4lop oro.l M potassiurn fbrricyani<Je solution r' abour I rnl- of , fe*ous strlfaie solrrtio'. c.rnpare ,hi- ;;J;o il,r, obtairrerJ when rlre . potassium ferricyanide was adied to the various sol,rtion,, .",,rri,,i"* ,r,,;l*. vhat concrr-rsio's can be made nor" ii," ,;;;;rr; in step e? Part II. 'Reactions invorving Merar coupres -'fwo Metars irr colrracL a' Prepare "!!::l.ro1, nrL of agrr-apyrr sorurior,,i, fniluws: Freat arrorrt 200 r'r_. of distilled water t. a gentlJboil.' Remo". irt" iu,,,,., a'cl srir. itr 2 g of powdered agar-agar' dontirtrre the heating."a .t1i1 rrntil the :rgar- i.s clispersecl. b. Add about iO arlp, of 0..1M potassiurn feiri.yanide ancl5 drops o[0.]%, phenolphtharein indic*ror ro ,t,. ;qir;;;'r"ii;;,,. stir r horougrrry. c. Mrile the agar-agar solution i, .ooiirrg,"1,r.p;. L,,r crearr brighr nairs as shown i. Figure la4- Place one nail on one side of a perri dish or.sr'all beaker. Bend another nair sharpty *i,h';;;;i, "i pr;.* arrrr 'race ir on trrr: other side of the dish. Twisr. il.rn pi.."'"r.t irJ rnop.r.,ryirc arourr<J a.rhircl ,t ii 1i t ,.1 &€9,*. [r,PQ, l&s"!I Distilled water