A fictional cubed-shaped bacterium, Bacterius cubis, occupies a volume of 2.0 femtoliters. This particular type of bacteria is known to communicate with its own species by secreting a small molecule called bactoX ( MW=126.9 g/mol ). A. Each bacterium contains 7140 bactoX molecules that can be secreted. How many moles of bactoX are present in a 3.0 μL sample volume that contains 7.512×106 bacterial cells?

There are   moles of bactoX present in a 3.0 μL sample volume that contains 7.512×106 bacterial cells

Explanation:

Given that:

The number of molecules present in one bacterial cell is molecules

and the sample  contains molecules.

Number of moles = number of molecules /Avogadro's number

where;

Avogadro's number = 6.023 × 10²³

Number of moles =

Number of moles = moles

So;   moles  is present in one bacteria cell

Similarly;  the sample  contains molecules.

Therefore; the number of moles present in the bactoX is =

= moles

nacl is added to the aqueous of what? ? in order to get a proper answer you have to specify the exact composition of the aqueous solution.