The purpose of this lab was to cause a chemical reaction between magnesium and oxygen and then determine the percent composition of each substance in the final product, magnesium oxide. By doing this, the empirical formula of the product (ideally MgO) would be able to be calculated.
Clean a crucible and cover and dry it over a Bunsen burner for 3 minutes. Wait until the crucible has cooled, then measure its mass. Cut a 10 centimeter piece of magnesium ribbon into small pieces (while avoiding touching the magnesium with bare hands). Place the cut-up magnesium in the crucible and measure the total mass. Cover the crucible, put it in the clay triangle, and heat it with the Bunsen burner for three minutes. Tilt the crucible’s…show more content… Instead, our empirical formula had 3 more magnesium moles than oxygen moles. In actuality, magnesium oxide must have an equal number of magnesium and oxygen moles.
5) Justify any deviations from the theoretical results. (For example, if your ration was too high or too low, cite and explain specific reasons why this might be the case.)
Since we did not have enough oxygen, it is likely that we either did not add enough water or all of the magnesium did not react. Supposing that we had added more water, more oxygen may have been added to the compound, since oxygen from water combines with the magnesium nitride (which is the resulting compound of heated magnesium coming into contact with air). Or we could have not heated the magnesium enough, making some of it unable to react with oxygen.
6) If you did not heat the magnesium long enough for full reaction of the metal, how would your empirical formula differ? Explain.
There would be less oxygen moles than magnesium moles in the empirical formula. Because the magnesium needs to be heated to be able to react with nitrogen in the air (making magnesium nitride) and eventually the oxygen in water, magnesium that is not heated all the way through would result in less bonding of magnesium with oxygen and overall less molar mass of oxygen in the