1 1/2 liter of water is the same volume as....5000mL, 0.5 cc? 500cm3? or 5dm3?

Hello jrh99-ga 

Thank-you for your question.

1 1/2 liters of water is not the same volume as any of the others that
you have mentioned.

1.5 liters is the same as:

1500 mL
1500 cc
1500 cm3
1.5 dm3

There is an excellent online volume conversion calculator here:
http://www.convert-me.com/en/convert/volume

Simply type 1.5 into box next to the liter label and press convert. 
The page then refreshes to show the volume in many different and
exotic volume measurements.

If you have any further questions on this subject please ask for
clarification and I will do my best to respond swiftly.

Unless the questioner is actually saying one half liter as opposed to
one and a half liters in which case 500cm3 would be the only correct
answer.

I would assume that he meant one half litre because of the options he
gave on the answer and the fact litre wasn't pluralised.