A sample of 0.250 g of nickel complex was titrated with 0.150 M EDTA. If the titration of the nickel sample required 7.5 mL of EDTA to reach the equivalence point, what is the percent nickel in the sample?
Ni^2+ + 2EDTA ==> Ni(EDTA)2
mols EDTA - 0.0075 x 0.15 = ?
mols Ni = 1/2 that
g Ni = mols Ni x atomic mass Ni = ?
%yield = (g Ni/mass sample)*100 = ?
To find the percent nickel in the sample, we need to determine the number of moles of nickel and the total mass of the sample.
1. Calculate the number of moles of EDTA used:
Moles EDTA = Concentration of EDTA × Volume of EDTA used
= 0.150 M × 0.0075 L
= 0.001125 mol
2. EDTA reacts with one mole of nickel, so the number of moles of nickel is equal to the number of moles of EDTA used.
Moles of nickel = 0.001125 mol
3. Calculate the mass of nickel:
Mass of Nickel = Moles of nickel × Molar mass of nickel
= 0.001125 mol × 58.69 g/mol
= 0.066 gs
4. Calculate the percent nickel in the sample:
Percent Nickel = (Mass of Nickel / Mass of Sample) × 100
= (0.066 g / 0.250 g) × 100
= 26.4%
Therefore, the percent nickel in the sample is 26.4%.
To calculate the percent nickel in the sample, we need to determine the number of moles of nickel in the complex. Here's how we can calculate it:
1. Calculate the number of moles of EDTA used:
Moles of EDTA = volume of EDTA (in L) × molarity of EDTA
= 0.0075 L × 0.150 mol/L
= 0.001125 mol
2. Calculate the number of moles of nickel complex from the stoichiometric ratio:
Moles of nickel complex = Moles of EDTA / stoichiometric ratio
= 0.001125 mol / 1 (assuming 1:1 stoichiometry)
= 0.001125 mol
3. Calculate the mass of nickel in the sample:
Mass of nickel = Moles of nickel complex × molar mass of nickel
= 0.001125 mol × 58.6934 g/mol (molar mass of nickel)
= 0.065937 g
4. Calculate the percent nickel in the sample:
Percent nickel = (Mass of nickel / Mass of sample) × 100%
= (0.065937 g / 0.250 g) × 100%
= 26.38%
Therefore, the percent nickel in the sample is approximately 26.38%.