# Experimental Determination Of The Formula Of Magne

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Introduction: The purpose of this experiment is to determine the empirical formula of magnesium oxide formed by the reaction of magnesium with oxygen. To work out formula by the experiment it is necessary to measure the exact masses of each element present in a sample of a compound. Knowing the masses of magnesium and oxygen and its molar masses it is possible to find how many moles of each element is present in the magnesium oxide. The number of moles then can be used to obtain a molar ratio, which gives us the empirical formula of the compound. During the combustion reaction the ribbon of magnesium metal is heated, it reacts with oxygen from the air in a crucible, producing magnesium oxide: magnesium + oxygen → magnesium oxide We measure the mass of magnesium we use for the reaction, and the mass of magnesium oxide produced at the end of it, then we can work out the mass of oxygen that has been combined with the magnesium. Hypothesis: As we know, the empirical formula of a compound indicates the simplest whole number ratio of atoms of each element present in it. According to Lewis formula of ionic bonding: ionic bonding and the formula of oxidation reaction of Mg: 2Mg + O2 => 2MgO indicates that in one molecule of a magnesium oxide chemical compound there is only one atom of magnesium and one atom of oxygen, therefore by carrying out the experiment the molar ratio of Mg and O is predicted to be 1:1. Method: The materials used in conducting this experiment are as follows: safety goggles, a porcelain crucible with a lid, a length of magnesium ribbon (about 25 cm in length), emery paper, a laboratory balance, a pipeclay triangle, a tripod, a Bunsen burner, and crucible tongs. 1. A dry porcelain crucible with lid was weighed using a laboratory balance and the mass was recorded. 2. The surface of magnesium ribbon was cleaned with emery