4. which would contain more atoms a mole of K atoms or a mole of Au atoms?
23. Cosmone is a molecule used by fragrance manufacturers to provide a rich and elegant musky essence to many perfumes. Cosmone has the molecular formula C15H26O.
a) calculate the molar mass of cosmone.
b) calculate the mass of 3082 moles of cosmone.
c) Calculate the number of molecules of cosmone in a sample containing 8.36 X10 (-4) mol cosmone.
d) Calculate the number of moles of carbon in a 8.35- mol sample of cosmone.
e) Calculate the mass of oxygen in a 4.29 g sample of cosmone.
f) Calculate the mass of a sample of cosmone that contains 6.58 x 10 (19)
g) Calculate the mass of one molecule of cosmone,
h) Calculate the number of atoms of carbon in 8.00 g of cosmone.
27.calculate the percent composition by mass of these compounds
A.NaBr d. SiCl4
37. Determine the empirical formula for each of the following using the given masses：
A）a compound containing 26.08 g zinc , 4.79 g carbon, and 19.14 g oxygen
b) a 150.0 g sample of a compound containing 57.66 g carbon , 7.26 g hydrogen and the remainder, chlorine
c) a 75.0 g sample of an oxide of vanadium containing 42.0g V and the remainder ,oxygen
47.ethanedioic acid a compound that is present in many vegetables , has a molar mass of 90.04g/mol and a composition of 26.7%C, 2.2% H , and 71.1% O. What is the molecular formula for this substance?