This is not a sort of an answer which is common on this site, but asking [wolframalpha][1] about the answer [it says][2]: $$9971 \text{grams}$$ [1]: http://www.wolframalpha.com [2]: http://www.wolframalpha.com/input/?i=mass+of+10+litters+of+water+at+298+kelvin+and+1+atm+pressure