We can determine the content (%) of calcium in milk through complexometric analysis by titration with EDTA. If we weigh 0.50 g of milk powder and titrate with EDTA 0.010 mol/L. What percentage of Ca2+does the milk if expended EDTA was 13.6 ml?
millimols Ca = mL EDTA x M EDTA = ?
grams Ca = mols Ca x atomic mas Ca = ?
% w/w = (grams Ca/mass sample)*100 = ?
* Calculation of the quantity in moles of CA2 +:
V (EDTA) L * M (EDTA) = > 0.0136 * 0.010 = > 0.000136 moles CA2 +
* Calculation of the quantity in grams of Ca2 +:
Moles Ca2 + * atomic mass Ca 0.000136 * 40.078 = > 0.00545 g
Finally, percentage (%) of Ca2 +:
% = (mass g Ca2 +/sample) * 100
% = (0.00545/0.50) * 100
% = 0.0109 * 100
% = 1.09 g of CA2 +
To determine the percentage of calcium in milk through complexometric analysis, you can follow these steps:
1. Calculate the moles of EDTA used in the titration:
Moles of EDTA = concentration of EDTA solution (mol/L) × volume of EDTA solution used (L)
In this case, the concentration of EDTA solution is given as 0.010 mol/L and the volume used is 13.6 mL, which is equal to 0.0136 L:
Moles of EDTA = 0.010 mol/L × 0.0136 L
2. Use the stoichiometry of the reaction to determine the moles of calcium:
The balanced chemical equation for the reaction between calcium and EDTA is:
Ca2+ + EDTA -> Ca-EDTA
From the equation, it can be inferred that each mole of EDTA reacts with one mole of Ca2+. Therefore, the moles of calcium present in the milk powder is equal to the moles of EDTA used.
3. Calculate the percentage of calcium in the milk powder:
Percentage of calcium = (moles of calcium / mass of milk powder) × 100
In this case, the mass of the milk powder is given as 0.50 g:
Percentage of calcium = (moles of calcium / 0.50 g) × 100
By plugging in the values calculated in step 1 and step 2, you can determine the percentage of calcium in the milk powder.