I need help with one chemistry problem.?

Question

I'm new to chemistry. so I really need your help.
I have never learned chemistry in america, sometimes it's really hard to understand the question's meaning.

here is the chemistry problem.

Q) Ethanol (the drinking alcohol), C2H5OH, has a density of 0.789 g/cm^3. You have a 5.0 gallon drum of alcohol. How many pounds does the alcohol weigh?

I don't know how to solve the problem....

could you please help me?

thanks in advance!

Answer 1

One (liquid) gallon can be (unit) converted to 3.785 412 L, or 3.785 412 dm^3 = 3785.412 cm^3 = 3785.412 mL.
Now volume x density is the weight. So:
3785.412 cm^3 x 0.789 g/cm^3 = 2986.7g = 2.9867 kg.
Perform the unit conversion again to "pounds":
1 pound = 454 g
2986.7/454 = 6.58 (pounds)
I would like to suggest you to keep a table of the english units for your convenience of unit conversions.

http://en.wikipedia.org/wiki/English_unit
http://en.wikipedia.org/wiki/U.S._customary_units#Liquid_volume