5. 1.16 x
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
kg
number of moles = 
number of moles = 
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
grams

x = 1.16 x
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
.
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 = 
density x volume = mass
0.79 x 750 = 592.5 grams
number of moles = 
number of moles of ethanol = 
= 12.86 moles of ethanol