Problem :
How can the emprical formula be determined when magnesium and oxygen
combine in the lab?
Procedure:
1. Cut a 30cm length of magnesium ribbon into 1cm pieces.
2. Place the pieces in a crucible and measure the mass of the crucible and its
contents.
3. Cover the crucible and heat it gently for two minutes.
4. Uncover the crucible , partially, and heat strongly for at least 10 minutes.
5. Allow to cool and determine mass of reacted magnesium.
Picture:
Label on picture:
1. heating stand
2. ring clamp
3. crucible
4. wire gauze
5. Bunsen burner
Data Chart:
a. Mass of empty crucible = g
b. Mass of crucible + Mg = g
c. Mass of crucible + O = g
{after it burns}
Chemical Reactions:
Magnesium + Oxygen -----> Magnesium Oxide
2Mg + O2 -----> 2MgO
Calculations:
1. Find the mass of Mg used : b-a
2. Find the mass of O used: c-b
3. Determine the empirical formula:
Safty Notes:
1. Do not look at the burning Mg.
2. Don't place any Mg in a open flame.
3. Wear goggles and apron.
Conclusion:
1. How many grams of Mg did you have in the experiment?
2. How many grams of O did you have in the experiment?
3. How many moles of Mg did you have?
4. How many moles of O did you get?
5. What did you get for your empirical formula?