Determine the percentage of nickel present in hydrated nickel sulphate by complexometric titration with EDTA.
by
rahul1994 (student)
UNIT 2 - PPA 1 - Complexometric Determination of Nickel Using EDTA
AIM
The aim of the experiment is to determine the percentage of nickel present in hydrated nickel sulphate by complexometric titration with EDTA. The aim will be achieved by complexometric titration of EDTA into a solution of nickel sulphate until a colour change is observed. EDTA act as a ligand because of its structure in alkaline conditions it is able to form stable complexes with metal ions such as nickel as it has the capacity to donate electron and it has six lone pair of electrons which forms an octahedral complex in a 1:1 ratio with Ni2+ or metal ions.
Ni2+ (aq) + EDTA2- (aq) ➔ Ni-EDTA (aq)
The percentage mass of nickel in nickel sulphate is given by the following calculation.
mol of nickel sulphate (NiSO4.6H2O) = 58.7 + 32.1 + (4*16) + 6(2*1) + 16)
= 262.8g
% mass of nickel = 58.7 / 262.8 * 100
= 22.33%
PROCEDURE
Approximately 2.6g of hydrated nickel sulphate was weighed using a weighting bottle, and 25cm³ of deionised water was transferred in a 100cm³ beaker followed by 2.6g nickel sulphate. The weighing bottle was reweighed to ensure that all the nickel salt was transferred to the beaker and any mass need to be deducted for calculation purpose. The solution was stirred until the solid dissolved and the solution was transferred to a 100cm³ flasks. the beaker was rinsed several times to ensure that all the solution had been transferred to the flask and the solution was made up to the graduation mark by adding deionised water, the solution was inverted several time to ensure a proper mix.
AIM
The aim of the experiment is to determine the percentage of nickel present in hydrated nickel sulphate by complexometric titration with EDTA. The aim will be achieved by complexometric titration of EDTA into a solution of nickel sulphate until a colour change is observed. EDTA act as a ligand because of its structure in alkaline conditions it is able to form stable complexes with metal ions such as nickel as it has the capacity to donate electron and it has six lone pair of electrons which forms an octahedral complex in a 1:1 ratio with Ni2+ or metal ions.
Ni2+ (aq) + EDTA2- (aq) ➔ Ni-EDTA (aq)
The percentage mass of nickel in nickel sulphate is given by the following calculation.
mol of nickel sulphate (NiSO4.6H2O) = 58.7 + 32.1 + (4*16) + 6(2*1) + 16)
= 262.8g
% mass of nickel = 58.7 / 262.8 * 100
= 22.33%
PROCEDURE
Approximately 2.6g of hydrated nickel sulphate was weighed using a weighting bottle, and 25cm³ of deionised water was transferred in a 100cm³ beaker followed by 2.6g nickel sulphate. The weighing bottle was reweighed to ensure that all the nickel salt was transferred to the beaker and any mass need to be deducted for calculation purpose. The solution was stirred until the solid dissolved and the solution was transferred to a 100cm³ flasks. the beaker was rinsed several times to ensure that all the solution had been transferred to the flask and the solution was made up to the graduation mark by adding deionised water, the solution was inverted several time to ensure a proper mix.