Hi answer these 2 questions. The two photos are just guide1. What is the color of the doubly ionized Eriochrome Black T indicator in slightly basic solution? 2. Is it possible to use the sodium salt of EDTA as a primary standard? ..ll.l 0.02KB/s10:4559%Experiment N...Objective: At the end of the experiment, the student should be able to determine the totalhardness caused by dissolved calcium and magnesium ions by complexationtitration.Materials and ReagentsErlenmeyer flasksBeakerPipetStirring rodNa,H,Y.2H,Ocalmagite indicatorNH,CI/NH,buffer, 3.2 g NH.CI + 28.5 ml conc. NH, diluted to 500 mlvolumetric flaskburetdropperwatch glassNaOHProcedureA. Preparation of EDTA solution1. Weigh approximately 0.94 g of the dihydrate Na:H;Y.2H;O in a 100-ml beaker and dryfor one hour at 80°C.2. Cool and add about 50.00 ml distilled water into the beaker and stir to dissolve theEDTA.3. Transfer the solution into a 250-ml volumetric flask through a funnel.4. Add another 50.00 ml distilled water in the beaker to completely remove the EDTAremained in the beaker5. Transfer the washings into the flask and add water up to the mark.6. Correct the mass of the EDTA by subtracting the 0.30% moisture it usually contains.Using this mass and the formula weight of the sodium salt dihydrate, calculate themolarity of the EDTA solution prepared. The solution prepared should be approximately0.0100MB. Preparation of pH 10 buffer solution1. Weigh approximately 3.500g of ammonium chloride in 100 ml beaker2. Add 30.00 ml of concentrated aqueous ammonia with sufficient distilled water to yield50.00 ml of solution.C. Analysis of the unknown1. Pipet a 100.00 ml water sample assigned to your group into a 250 ml Erlenmeyer flaskand swirl the solution.2. Add 3-4 ml of the ammonia-ammonium chloride buffer to the flask and add sufficientcalmagite indicator so that the solution turns a deep red.3. Heat the solution to between 60-80°C, place a magnetic stir bar in the flask4. Titrate with the EDTA solution until the last tint of red disappears. ..l.l 0.23KB/s?10:4559%Experiment N...Experiment # 8Determination of the Total Hardness of Water by Complexometric TitrationThe technique involves titrating metal ions with a complexing agent or chelating agentThis method represents the(ligand) and is commonly known as complexation titration.analytical application of a complexation reaction in which a simple ion is transformed into acomplex ion and the equivalence point is determined by using metal indicators orelectrometrically. A primary standard solution of EDTA (the dihydrate of the disodium salt ofethylenediaminetetraacetic acid - typically written as NaH,Y) is prepared and used it todetermine the magnesium content of an unknown solution. EDTA from a 1:1 complex withpractically every metal on the periodic table most of which are stable enough for titration. Themole relationship in metal-EDTA complexes is a result of the ability of the Y“ anion to interactwith acan then occupy four, five, or six coordination positions around a central metal ion. Because ofthis fact only one to one metal ligand complexes are formed eliminating the stepwise formationof simpler complexes and minimizing calculations.performed in neutral or alkaline solutions which control not only the pH but the species prevalentin the EDTA (remember it is a weak acid so it's protonation depends on pH). Typically a bufferis used to maintain the pH at a specific value based on the metal to be complexed.of six functional groups – fourrbonyl groups ae groups. The groupsMost metal - EDTA titrations areIn this equation, a buffer of sufficiently high pH is used to ensure the equilibriumbetween Mg" and the EDTA anion lies far to the right promoting the complete complexation ofthe magnesium ions.MgH;Y → MgY²*2HNHH2N--č CH3MgEDTA[Ca-EDTAP complex-CH2H3C c-NH2HNte)EDTA[Mg-EDTAP complexb)The complex of the indicator calmagite with magnesium ions is a bright wine red. Theend point corresponds to the disappearance of the last trace of red to leave a pure blue. Since thereaction of the indicator complex with the EDTA is somewhat slow the solution is usuallywarmed during the titration.

Complexometric titration involves the formation of a complex between ligand and metal ion present in…

Answered: 1. What is the color of the doubly…

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...