Step-by-step explanation:
Number of moles present in a substance is equal to the mass divided by molar mass.
Mathematically, No. of moles =

As it is given that mass is 4.00 g and molar mass of
is 46.07 g/mol.
Hence, calculate the number of moles of
as follows.
No. of moles =

=

= 0.086 mol
Thus, we can conclude that number of moles of
present in 4.00 g is 0.086 mol.