A big irregular shaped vessel contained water, the conductivity of which was 2.56×10−5 S cm−1 . 500 g of NaCl was then added to the water and the conductivity after the addition of NaCl, was found to be 3.10×10−5 S cm−1 . Find the capacity of the vessel if it is fulfilled with water ( ΛM∘ of NaCl = 149.9).