CHEM 205 Chapter Notes - Chapter 2: Unified Atomic Mass Unit, Bromine, Natural Abundance

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In 1774, antoine lavoisier (1774-1794) performed an experiment in which he heated a sealed glass vessel containing a sample of tin and some air. He found that the glass before heating and the glass after heating were the same. Through further investigation, he proved that the product of the reaction, tin calx, consisted of the original tin together with a portion of the air. Problem: a 0. 455g sample of mg is allowed to burn in 2. 315 g of o2 gas. After the reaction, no magnesium remains and the mass of unreacted oxygen is 2. 015g. Mass before reaction: 0. 455g magnesium + 2. 315g oxygen = 2. 770 g. 2. 770g mass after reaction =? g magnesium oxide after reaction + 2. 015g oxygen after reaction g magnesium oxide after reaction = 2. 770 g mass after reaction 2. 015 g oxygen after reaction = 0. 755 g magnesium oxide after reaction.