From the molecular formula of the compound, given as
, it’s evident that 1 mole of
consists of 3 moles of oxygen.
In one mole, there are
atoms, thus, having 3 moles of oxygen corresponds to
atoms of oxygen.
This means that 1 mole of
contains
oxygen atoms.
1 atom of oxygen is equivalent to
moles.
From the number of oxygen atoms provided, which is
, it will be contained in
moles of
.
The molar mass of
is 125.388 g/mol, enabling us to compute the mass as follows:

By rearranging the equation above,

Substituting the values gives us,

Thus, the mass of
amounts to 2.16 g.