1. AP chemistry Big idea 1
Titration of Milk

2. Safety Must wear aprons Gloves goggles Disodium EDTA dehydrate-
Calcium carbonate-
6M HCl
8 M NH3
0.1 M Na2S
0.1 M Magnesium chloride
Ammonium chloride
Calmagite
Safety
Must wear aprons
Gloves
goggles

3. Pre lab
Mass of calcium carbonate needed so that a titration with a M EDTA would require 25mL titrant to achieve end point
25mL EDTA x 𝑚𝑜𝑙 𝐸𝐷𝑇𝐴 𝑚𝐿 𝐸𝐷𝑇𝐴 x 1 mol CaCO3 1 mol EDTA x g CaCO3 1 mol CaCO3
= g CaCo3

4. Prelab
Acid required for calcium carbonate to fully dissociate. Determine the amount of 6 M HCl that must be added to dissolve the mass of CaCO3 you calculated in ?1
CaCO3 + CO3 Ca + CO3
2H + CO3  H2CO3  H2O +CO2
0.025 g CaCo3 x 1 mol CaCO g CaCO3 x 2 𝑚𝑜𝑙 𝐻𝐶𝑙 1 mol 𝐶𝑎𝐶𝑂3 x 1000 mL HCl 6 mol HCl
= .083 mL HCl

5. How it works

6. Concentration of EDTA
g CaCO3 mL EDTA x 1 mol CaCO g CaCO3 x 1 mol EDTA 1 mol CaCO3 x 1000 mL EDTA 1 L EDTA =___________ M

7. Hard water