1. Magnesium Lab 2 Quantitative: weight before and after burning.

2. Theory/ Justification ► Magnesium plus Oxygen -> Magnesium Oxide ► Mg + O -> MgO ► MgO should weigh 40/24ths as much as Mg (almost double)

3. One Possible Procedure (write yours as you go) ► Carefully weigh clean piece of magnesium and clean crucible (crucible is fragile- careful!) ► Burn magnesium ► Collect all residue and return to crucible ► Weigh crucible

4. Prediction from Theory: ► Weight of MgO = 40 * Weight of Mg / 24

5. Example Data Table ► Find the weights of Mg and O. ► Weigh your Mg (weight of Mg + crucible- weight of empty crucible) ► Weigh your MgO (weight of MgO + crucible – weight of empty crucible) Weight of Mg and O (from P.T.) ____ g/mol Weight of Mg Weight of MgO

6. Comparison with Theory ► Describe how close you got to the predicted weight of your MgO ► Discuss possible reasons for any difference. ► Conclude: does your data support the theory? Weight of Mg (initial) Predicted weight of MgO Actual weight of MgO