I agree with Mike. To actually give you an answer to the question you asked, yes - mix up a litre and store in smaller bottles that contain the right amount to use to develop one tank's worth of film. In my circumstances I mix up a litre of D76 and store it in 4x 250ml bottles. Each bottle then gives me exactly the right amount to make up 500mls of working solution to develop one roll of 120 film. I can then use just that one bottle, leaving the other three unopened and sealed until they're required. The alternative would be to leave a 1 litre bottle containing 750mls of developer and 250mls of air, encouraging oxidization.