What information woul you need to predict the mass of 40 ml of any liquad?

The molar mass of the substance

To predict the mass of 40 mL of a liquid, you would need to know the density. Density is a measure of mass per volume, so since you have a volume measurement, you’d need to know the density to retrieve the mass.

Maybe you should get some from your teacher and learn more so you can get your grades up and maybe study a bit more