Determination of nickel Essay

INTRODUCTIONEDTA (HY) is widely use to determine ad desegregateed bags in thickeningometric (a volumetric abstract where the contriveation of a strained complex is used to indicate the windup height of a titration) titrations as it forms stable complexes with to the highest degree alloy ions. EDTA is a tetracorboxylic acid and in alkaline conditions, it exists as Y ions, which form 11 complexes with metal ions homogeneous nickel(II) ionsY + Ni NiYA metal ion indicator (an organic dye which changes colour when it stings with metal ions) shows the end of an EDTA complexometric titration. However, for a metal ion indicator to be suitable in n EDTA titration, it must not bind as strongly with metal ions as EDTA does. Murexide is therefore suitable.AIMThe aim of this prove is to determine the percentage of nickel in a nickel(II) flavour using EDTA. around 2.6g of hydrated nickel(II) sulphate was transferred to a weigh bottle and the contents weighed and about 25cm of deioni sed piss was added to a 100cm beaker and the nickel transferred to the peeing. The bottle was weighed without whatsoever remaining flavour and indeed the garland was stirred until the solid was dissolved onward the resulting solution was transferred to a 100cm measurement flask.The beaker was then rinsed several times with deionised water and the rinsings were added to the standard flask. The solution was filled up to the step mark with deionised water and the flask was stop up and inverted several times to mix the contents.The burette was rinsed with 0.01moll EDTA and filled with the same solution. The 20cm pipette was rinsed with a little of the nickel table flavour solution and then 20cm of it was pipetted into a cone-shaped flask. The solution was diluted to about 100cm with deionised water and murexide indicator (approximately 0.05g) was added to the diluted nickel salt solution along with appromimately 10cm of ammonium chloride solution.The mixture was titrated w ith the EDTA solution and after and after the plus of about 15cm the solution was made alkaline by addingapproximately 10cm of 0.88 aqueous ammonium hydroxide (concentrated ammonia solution). The titration was then continued to the end point, shown by the first appearance of a blue-violet colour. Titrations were repeated until two concordant results were obtained.RESULTS volume of 1 Mole of NiSO4.6H2O 262.8gMass of 1 Mole of Ni 58.7gTheoretical portion by MassVolumes of EDTA used in titration 1st 20.2cm32nd 20.9cm33rd 20.4cm3 number 20.5cm3Moles of EDTA used = 0.1 x 0.0205 = 0.00205 MolesEDTA reacts with nickel note in a 11 ratio, so the number of moles of nickel note in 20cm3 of the salt solution = 0.00205MolesNumber of Moles in 100cm3 = 0.00205 x 5 = 0.01025 MolesNumber of Moles of Ni2+ in 2.6g of Nickel salt = 0.01025Weight of Ni2+ in salt = 0.01025 x 58.7 = 0.601675gCONCLUSION% Mass of Nickel in salt = 0.601675 2.60 = 23.14%