A reaction of 58.1 g of Na and 54.9 g of Br2 yields 67.8 g of NaBr . What is the percent yield?

Asample of the male sex hormone testosterone, c19h28o2, contains 3.88×10^21 atoms of hydrogen.(a) how many atoms of carbon does it contain? (b) how many molecules of testosterone does it contain? (c) how many moles of testosterone does it contain? (d) what is the mass of this sample in grams?

Given that 1 mi = 1760 yd, determine what conver- sion factor is appropriate to convert 1849 yd to miles; to convert 2.781 mi to yards.

Fossil fuels are organic compounds that are made from