Volume 2 (Issue 2) Download

Volume changes during dissolving of ionic compounds in water

S.B. Kanade, A.P. Malandkar, Prakash Nawale and P.K. Joshi

 

Abstract

When ionic salts (which break up into ions easily, in water) are dissolved in water, the increase in volume is less than the sum of the two volumes (salt and water). But after a turning point, this increase is additive in nature. Before this turning point, the number of ions keep increasing but the number saturates beyond the turning point, indicated by saturation of current passing through the solution. This turning point is not observed in solutes which do not break up into ions. In present experimental work, these properties are established using a simple school level experiment. A connection between refractive index of solution and point of saturation is also established.