Which of the following compounds is used as an adsorbent in column chromatography?

Which of the following statements is incorrect?

Fill in the blanks:
$1$. In differential extraction from two layers,the .......... layer is above because .............
$2$. The organic solvent used in differential extraction is .......... in water.
$3$. If an organic compound is ......... soluble in an organic solvent,then the continuous extraction technique is used.
$4$. ........ solution is added to produce the precipitate of halide for the estimation of halogen.

Which are the types of chromatography?

Three organic compounds $A$,$B$ and $C$ were allowed to run in thin layer chromatography using hexane and gave the following result (see figure). The $R_f$ value of the most polar compound is $............\, \times 10^{-2}$

The fragrance of flowers is due to the presence of some steam volatile organic compounds called essential oils. These are generally insoluble in water at room temperature but are miscible with water vapour in the vapour phase. $A$ suitable method for the extraction of these oils from the flowers is: