The principle of column chromatography is :

At room temperature, a dilute solution of urea is prepared by dissolving 0.60 of urea in 360 g of water. If the vapour pressure of pure water at this temperature is 35 mm Hg, lowering of vapour pressure will be. (molar mass of urea = 60 g mol^–1)

The major product of the following reaction is :

The species that can have a trans-isomer is :
(en = ehane-1, 2-diamine, ox = oxalate)