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1 liter is defined as 10 by 10 by 10 cm
The density of ice is 0.9167 g/cm whereas the density of water 0.9998 g/cm (this is at 0, water and ice change their density with temperature).
1 liter thus equals 1000cm which means that:
1 liter of Water (0) weighs: 999,8 grams
and 999,8 grams of water (as matter cannot just disappear(usually)) turns into 999,8 grams of ice, which is, in liters: