Dehydrogenation of $CH_3-CH(OH)-CH_3$ gives

When concentrated $H_2SO_4$ reacts with $X$ at a temperature of $160 - 170 \, ^\circ C$,ethylene is obtained. What is $X$?

Consider the following reaction sequence:
$CH_3CHO$ $\xrightarrow[(ii) H_3O^+]{(i) CH_3MgBr} A$ $\xrightarrow[\Delta]{Conc. H_2SO_4} B$ $\xrightarrow[(ii) H_2O, OH^-]{(i) B_2H_6} C$
$A$ and $C$ are:

An alcohol of formula $C_9H_{12}O$ reacts with $Na_2Cr_2O_7$ to form a compound having formula $C_9H_{10}O$. The original alcohol might be

Find out the major product from the following reaction.

Glycerol is a trihydric alcohol. It contains . . . . . .