AbstractPartition co‐efficient of the chlorides and Nitrates of Nickel and Cobalt were studied and the average partition co‐efficients have been determined. Effect of temperature, acids and ketones have also been investigated. The partition co‐efficient increases with the increase in temperature in case of Nitrates while a reverse influence is seen in the case of the Chlorides. Acids have analogous effect to that of common ion and depress solubilities of Chlorides and Nitrates in water. Lower ketones like acetone, methyl ethyl ketone and acetonyl acetone appreciably decrease the partition co‐efficient. The other Ketones did not show any appreciable partitioning