for #7 the molecular volume is 0.000000360mL or 3.60x10^-7

For #8 please use dimensional analysis

8. Using your molecular volume (mL/molecule, #5): what is the volume in UL) of 7.15 x 10-5 moles of this compound? Use dimensional analysis (and use the expected value for Avogadro's number): 9. Suppose a different fatty acid molecule were used, with a molecular volume of 6.82 x 10-22 mL/molecule and a density of 0.915 g/mL. Use the expected value for Avogadro's number with dimensional analysis to calculate its molar mass (in g/mol)