The annual production of sodium hydroxide in the U.S. in 1994 was 25.83 billion pounds.How many grams of sodium hydroxide were produced in that year?The density of sodium hydroxide is 2.130 g/cm3(cube).How many cubic kilometers were produced?

I know how to get the first part which is easy for 1 pound is equal to 453.59 grams. But for the second part I don't understand how you are suppose to convert 2.130 g/cm^3 to km. Can anyone please help me out on this one. Thank you and have a wonderful day

Here the requirement is to work out the volume.
Density is mass per unit volume.
Hence to get volume, divide mass by the density.
After you convert the pounds to grams, divide it by the density ie 2.130 gm/cm^3.
This gives you the volume in cm cube.
Now you need to convert it to kilometre cube.
1 cm = 10^-5 KM.
so 1 cm cubed = 10^-15 KM cubed.
Divide the volume in cm cube by this to get the answer in km cube.