JEE Main 9 Jan 2019 Shift 2 Solved Paper

The molecular species or substance, which concentrates or accumulates at the surface is termed as adsorbate and the material on the surface of which adsorption takes place is called adsorbent.
Using the principle of adsorption chromatography, qualitative and quantitative analysis of benzaldehyde can be done from its mixture with acetonitrile. Here, a mobile phase moves over a stationary phase (adsorbent). Adsorbents used are alumina and silica gel.
The sample solution of benzaldehyde and acetonitrile when comes in contact with the adsorbent, benzaldehyde gets adsorbed on the surface of the adsorbent. So, benzaldehyde acts as adsorbate whereas acetonitrile starts moving as mobile phase over the stationary phase of the adsorbate. Hence act as dynamic phase.