Experiment #2 Analysis of Magnesium
Purpose: determine amount of magnesium in a pill
300 enzymes so far need magnesium for function.
No magnesium metal occurs naturally.
Required Daily Allowance (RDA) of Mg is 0.30.4 g
Best sources are coffee, tea, leafy green vegetables
Those with a deficiency take Mg pills
I. A. Find x and y.
2+ 4 n
xMg + yEDTA ▯Mgx((EDTA)y)
1) Put around 100 mL of 0.01 M EDTA stock solution in a clean beaker.
2) Prepare a buret for EDTA solution.
a. Get a funnel and place in buret.
b. Make sure bottom is closed.
c. Fill around 1/4 with solution.
d. Stop buret at top with finger (WITH GLOVES) and invert it to wash the
e. Pour out into slop jar.
3) Fill buret with EDTA.
4) Put about 100 mL of 0.01 M Mg stock solution in a clean beaker.
5) Prepare a 2.5 mL volumetric pipette for Mg.
6) Get a pipette pump, put it on the volumetric pipette, and pump with Mg solution.
7) Invert to wash the pipette and put waste in slop jar.
8) Prepare 100 mL volumetric flask for H O.
9) Pipette 25 mL of Mg stock solution into volumetric flask. (USE PIPETTE PUMP)
10)Dilute to the mark with water (comes from the white tap). (If you pass the mark,
you must start over)
Calculate Magnesium solution
CVi=iCV f f
(0.01)(25) = x(100)
C f 0.0025 M
I. B. Titration
1) Put around 25 mL of NH buff3r in a small beaker.
2) Cover with a watch glass.
3) Pipette 25 mL (use pump) of Mg stock solution into an Erlenmeyer flask.
4) Add 1 dropp