To calculate the number of molecules, we can simply use this rule:
number of molecules = number of moles x Avogadro's number
In this problem, we have:
number of moles = 4.56 moles
Avogadro's number is a constant = 6.02 x 10^23
Substituting in the above equation, we can calculate the number of molecules as follows:
number of molecules = 4.56 x 6.02 x 10^23
= 2.74512 x 10^24 molecules
