After working through all of the Chapter 8 activities demonstrate your mastery o

Question

After working through all of the Chapter 8 activities demonstrate your mastery of the mole and Avogadro's number through this Have a calculator and a Periodic Table ready before you start. You will have an unlimited number of attempts to earn the high score on this quiz. Calculate the empirical formula of caffeine. The percent composition of caffeine is 49.48% carbon, 5.190% hydrogen. 28.85% nitrogen, and 16.48% oxygen. Omit subscripts and type the elements in the order listed. For example the formula for water is H20

Explanation / Answer

The percent composition of caffeine, carbon-49.48%, hydrogen-5.190%, nitrogen-28.85%, and oxygen-16.48%

49.48/12 (mol of C) = 4.123

5.190/1.01 (mol of H) = 5.139

28.85/14 (mol of N) = 2.061

16.48/16 (mol of O) = 1.03

divide all the fractions by least one to get relative moles of each element

C: 4.123/1.03 = 4

H: 5.139/1.03 = 5

N: 2.061/1.03 = 2

O: 1.03/1.03 = 1

the empirical formula of caffeine = C4H5N2O

Best wishes

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