A closely thermally insulated vessel contains 100 g of water at `0^@C`. If the air from this vessel is rapidly pumped out, intensive evaporation will produce cooling and as a result of this, water freeze. How much ice will be formed by this method? If latent heat of fusion is `80 cal//g` and of evaporation `560 cal//g` .
[ Hint If `m` gram ice is formed, `mL_(f)=(100-m)l_(v)`]
