5. 1.16 x [tex]10^{26}[/tex] moles  moles of pennies would be required to equal the mass of the moon.
6. 12.86 moles of ethanol are in a 750 ml bottle of vodka.
Explanation:
5 .Data given:
mass of penny = 2.5 grams
atomic mass of penny = 62.93 grams/mole
moles present in mass of the moon given as = 7.3 x [tex]10^{24}[/tex] kg
number of moles = [tex]\frac{mass}{atomic mass of 1 mole}[/tex]
number of moles = [tex]\frac{2.5}{62.93}[/tex]
0.039 moles of penny is present in 2.5 grams
0.039 moles of penny in 2.5 grams of it
so, x moles in 7.3 X [tex]10^{27}[/tex] Â grams
[tex]\frac{0.039}{2.5} =\frac{x}{7.3 X 10^{27} }[/tex]
x = 1.16 x [tex]10^{26}[/tex] moles
so when the mass of the penny given is equal to the mass of moon, number of moles of penny present is 1.1 x [tex]10^{26}[/tex] .
6.
Given:
vodka = 40% ethanol
volume of vodka bottle = 750 ml
moles of ethanol =?
density of ethanol =0.79 g/ml
atomic mass of ethanol = 46.07 grams/mole
so, from the density of ethanol given we can calculate how much ethanol is present in the solution.
density = [tex]\frac{mass}{volume}[/tex]
density x volume = mass
0.79 x 750 = 592.5 grams
number of moles = [tex]\frac{mass}{atomic mass of 1 mole}[/tex]
number of moles of ethanol = [tex]\frac{592.5}{46.07}[/tex]
                        = 12.86 moles of ethanol
