10,000 L (if you are talking about concentration)
the question can be a little more clear. Is that 5% a concentration or a molarity percent.
Anyway if you were thinking about concentration, if you are given a percent, you have to divide your persent by 100 due to the fact that you want to get rid of your percentage.
Then since you are given a solute for your solution, you have to divide the grams given by the number of percentage.
This seems like a large number but thinking about what was given to us, if you are mixing 500g (which is half a kg) in water to get a small concentration, you will need to have lots and lots of water.
Let me know in the comments if I answered the question correctly. I enjoy comments that people ask me.