The Rf value of compound A is 0.35 when TLC plate is developed in hexane and 0.45 when the plate is developed in diethyl ether. Compound B has an Rf value of 0.45 in hexane and 0.60 in diethyl ether. Hexane would be better for separating a mixture of compounds A and B by TLC. If yes then why?

No.

Explanation:

Under TLC chromatography, the compounds are separated based on the different affinity between stationary phase and mobile phase. The higher difference between Rf's of the compounds will produce the better separation.

In Hexane compound A has a Rf of 0.35 and compound B of 0.45.

The difference is 0.45 - 0.35 = 0.10

In dietyl ether, Rf of compound A is 0.45 and for compound B is 0.60.

The difference is 0.60 - 0.45 = 0.15.

As the difference in Rf is higher for dietyl ether:

Hexane would be better for separating a mixture of compounds A and B by TLC. NO. The better separation would be using dietyhl ether.

the atomic mass is the bottom number on the element.

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