CHEM 115 Lecture Notes - Lecture 3: Natural Abundance, Insect Repellent, Avogadro Constant
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Then the fractional abundance of 30si = 0. 0779 x. Atomic mass = 28. 0855 = {[27. 97693 0. 9221] + [28. 97649x] + [29. 97376(0. 0779 x)]} 28. 0855 28. 13 = - 0. 04 = - 0. 99727x x = - 0. 04 = 0. 04 = 0. 04. Therefore % natural abundance of 29si = 4% And % natural abundance of 30si = (7. 79 4) = 3. 79% = 4% The mass of 6li is 6. 01512 amu and the mass of 7li is 7. 01601 amu. Use the isotopic (atomic) mass of lithium to calculate the relative abundances of the two isotopes. Combining several factors in a calculation molar mass, the avogadro constant, percent. Potassium-40 (40k) is one of the few naturally occurring radioactive isotopes of elements of low atomic number. Its percent natural abundance among k isotopes is 0. 012%. Determining the empirical and molecular formulae of a compound from its mass percent. Dibutyl succinate is an insect repellent used against household ants and roaches.
