Calculating density?

Question

I have two problems to solve that I don't know how to do,I missed school last week and the teacher gave me the worksheet,but I couldn't get a copy of the notes that explained how to do it,haha.
1)A block of aluminum occupies a volume of 15.0 L and weighs 40.5 g.What is the density?
2) Mercury metal is poured into a graduated cylinder that holds exactly 22.5 mL.The mercury used to fill the cylinder weighs 306.0 g.From this information,calculate the density of mercury.
I know that density=mass/volume,but I don't know the relationship between volume,mass,and weight.Anyone care to give me a hand?

Wow.I'm an idiot.All I can say in my defense is that I tend to screw mass and matter up.Thanks for clearing that up and not making me feel like a complete retard.

And yes,I did copy that out wrong-supposed to say mL.God,this is going to be a long week =)

Answer 1

As far as these questions go, weight is the same as mass. Purists will say that weight is the gravitational force on something, and mass is the amount of material as defined by inertia, but don't let that bother you.

So for problem (1), density = mass (or weight) divided by volume. Care with units; if you want density as g/mL, which is usual, you need to have the volume in mL. By the way, I think you must have copied something out wrong there; 15.0 L of aluminum weighs much more than 40.5 g.

and for problem (2), same again; you are told in a very confusing way (why do schools do this?) that the volume is 22.5 mL.

Good luck.

Answer 2

hi, Density is the mass allotted over a given volume. for example, ethyl alcohol has a density of 0.seventy 8 g/mL, that's, one milliliter of ethyl alcohol is 0.seventy 8 grams. To calculate the density, you would be able to desire to weigh a compound and comprehend the quantity it occupies. Then purely divide the mass over the quantity and, voila! you have got here upon the density! nonetheless, you're able to to apply standardized glassware like pycnometers.

Answer 3

WEIGHT=MASS x g(=9.8)