please help with both

A student dissolves 15. g of styrene (C8H8) in 300 . mL of a solvent with a density of 1.20g/ml. The student notices that the volume of the solvent does not change when the styrene dissolves in it. Calculate the molarity and molality of the student's solution. Round both of your answers to 2 significant digits. Decide whether each molecule or polyatemic ion is polar or nonpolar. If the molecule or polyatomic ion is polar, write the chemical symbol of the atom dosest to the negative side. For example, it the molecule ware HCl and yoy decided the hydrogen atom was closest to the negative side of the molecule, you'd enter "H" in the last column of the tabie