Which of the following intermediates is formed when an alcohol reacts with concentrated $H_2SO_4$?

Explain the intermolecular hydrogen bonding in alcohols and phenols and its effect on their physical properties.

Dehydration of an alcohol $(A)$ gives an alkene. Ozonolysis of one molecule of this alkene yields two molecules of acetaldehyde. Identify the alcohol $(A)$.

The alcohol which gives a red color with the Victor Meyer test is:

Identify $Z$ in the following reaction sequence:
$C_2H_5OH$ $\xrightarrow{PBr_3} X$ $\xrightarrow{KOH(alc.)} Y$ $\xrightarrow[(ii) H_2O, \Delta]{(i) H_2SO_4} Z$

Identify $Z$ in the following sequence of reactions:
$CH_{3}-CH_{2}-CH_{2}-OH$ $\xrightarrow{PCl_{3}} X$ $\xrightarrow[\Delta]{alco.KOH} Y$ $\xrightarrow[H-OH/heat]{conc.H_{2}SO_{4}} Z$