In addition to determining elemental composition of pure unknown compounds, combustion analysis can be used to determine the purity of the known compounds. A sample of 2-naphthol, C10H7OH, which is used to prepare antioxidants to incorporate into synthetic rubber, was found to be contaminated with a small amount of LiBr. The combustion analysis of this sample gave the following results: 77.48% C and 5.20% H. Assuming that the only species present are 2-naphthol and LiBr, caluclate the percentage purity by mass of the sample.
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I did it in a weird way using ratios that makes more sense in your head.. 2-naphthol molecular weight is 144g which is 120g is carbon so thats 83.3333% carbon... your sample has 77.48 carbon, SO
oxygen is 16/ 144 or 11.1111%
using ratios 77.48/x = 83.333333/11.111111 find x =10.33% so 77.48 + 5.2 + 10.3348 + % LiBr = 100
so its ~ 7 % contamination of Li Br I hope that helps
oxygen is 16/ 144 or 11.1111%
using ratios 77.48/x = 83.333333/11.111111 find x =10.33% so 77.48 + 5.2 + 10.3348 + % LiBr = 100
so its ~ 7 % contamination of Li Br I hope that helps