The burning of the magnesium becomes uncontrolled (its burns brightly). Oops! How will this procedural error affect the reported mole ratio of magnesium to oxygen in the analysis? Explain.

Mass of crucible and lid 23.96g
Mass of Sample (Mg) .1018g

Heating the sample in Air
(if too much air comes in contact with the Mg ribbon rapid oxidation of Mg will occur by burning brightly)

Final mass of crucible, lid, and of product .6862g

3 answers

Well, my experience tells me of a greater related problem, when the Mg is burning rapidly, nitrogen from the air reacts to form Magnesium nitride, so in the final product contains oxides and nitrides, and you often assumed oxides only to get the mole ratio.
I am not certain what your instructor's question had in mind here.
if the burning of magnesium is complete , how will this procedural erorr affect the reported of magnesium mass of: magnesium in magnesium oxide? explain
if the burning of magnesium is complete, is seems that that is not a procedural error. after completion the mass of magnesium should be the same and now you have increased mass of magnesium oxide because before you had none