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

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

To determine the effect of the procedural error on the reported mole ratio of magnesium to oxygen in the analysis, we need to analyze the mass changes of the substances involved.

Given:
Mass of crucible and lid = 23.96 g
Mass of sample (Mg) = 0.1018 g
Final mass of crucible, lid, and product = 0.6862 g

To calculate the mass of oxygen in the product, we need to determine the mass difference before and after the reaction.

Mass difference = Final mass - Initial mass
= (Mass of crucible, lid, and product) - (Mass of crucible and lid + Mass of sample)
= 0.6862 g - (23.96 g + 0.1018 g)
= 0.6862 g - 24.0618 g
= -23.3756 g

The negative mass difference indicates that there was a loss of mass during the reaction. This loss of mass can be attributed to the combustion of magnesium resulting in the formation of magnesium oxide.

Since magnesium oxide (MgO) consists of 1 atom of magnesium (Mg) and 1 atom of oxygen (O), the mole ratio of magnesium to oxygen is 1:1. This means that for every 1 mole of magnesium, there is 1 mole of oxygen.

However, if the burning of magnesium became uncontrolled, it would lead to excessive oxidation and the consumption of extra oxygen. This would result in an incorrect determination of the mole ratio of magnesium to oxygen in the analysis.

In this case, due to the uncontrolled burning, the mass loss of the sample would be greater than expected, meaning that more oxygen was consumed than it should have been. As a result, the reported mole ratio of magnesium to oxygen would be lower than the actual 1:1 ratio.