Ethanol is a common laboratory solvent and has a density of 0.789 g/ml. what is the mass, in grams, of 151 ml of ethanol

With the density given, you can use to convert volume (mL) to mass (g)_, and vice versa. you can use the density as a conversion factor.

so if the density is 0.780 g/mL, then 0.789 g= 1 mL

now let's use this conversion factor to convert the mL to grams.