Name the factors responsible for the solubility of alcohols in water.
Solubility of alcohols in water depends upon the two factors.
(i) Hydrogen bonding Higher the extent of hydrogen bonding, higher is the solubility. The hydrogen group of alcohol form hydrogen bonding. Solubility increases with increase in the number of - OH groups in alcohols of comparable molecular masses.
(I) Compound (II) will form stronger H -bond due to two - OH group and hence has higher boiling point.
(ii) Size of alkyl/aryl group Higher the size of alkyl/aryl group (hydrocarbon part), lower is the extent of hydrogen bonding and lower is the solubility. Hence,
$$\mathrm{H}_3 \mathrm{C}-\mathrm{CH}_2-\mathrm{OH}>\mathrm{CH}_3 \mathrm{CH}_2-\mathrm{CH}_2 \mathrm{OH}>\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CH}_2-\mathrm{CH}_2 \mathrm{OH}$$
What is denatured alcohol?
Alcohol is used in large quantities in the manufacture of alcoholic liquors. Its continuous use damages the various vital organs. Therefore, to refrain the people from drinking alcohol, heavy excise duty is levied on the sale of alcoholic beverages. But, it is used in various industries as it is a very good solvent.
Therefore, industrial alcohol must be cheap. Thus, to provide cheaper alcohol to industries and to refrain people from drinking alcohol, it is mixed with some copper sulphate, pyridine, methyl alcohol or acetone.
Alcohol is made unfit for drinking by mixing some quantity of any of these substances in it. This is called denatured alcohol.
Suggest a reagent for the following conversion.
The given reactant is 
.
It is a secondary alcohol. Secondary alcohol 
gives ketone when oxidises by CrO$_3$ or pyridinium chlorochromate without carrying out oxidation at the double bond.
Out of 2-chloroethanol and ethanol which is more acidic and why?
2 -chloroethanol is more acidic than ethanol. Due to $-I$ effect (electron withdrawing group) of the Cl -atom electron density in $\mathrm{O}-\mathrm{H}$ bond decreases. So, $\mathrm{O}-\mathrm{H}$ bond of 2-chloroethanol becomes weaker than $\mathrm{O}-\mathrm{H}$ bond of ethanol. Thus, 2-chloroethanol is more acidic than ethanol.
Stronger acid due to $-I$ effect of Cl.
Suggest a reactant for conversion of ethanol to ethanal.
Ethanol can be oxidises into ethanal by using pyridinium chlorochromate. $\left(\mathrm{C}_6 \mathrm{H}_5 \stackrel{+}{\mathrm{N}} \mathrm{HCl} \overline{\mathrm{C}} \mathrm{CrOO}_3\right)$ in $\mathrm{CH_2Cl_2}$.
$\mathrm{H}_3 \mathrm{C}-\underset{\text { Ethanol }}{\mathrm{CH}_2}-\mathrm{OH} \xrightarrow{\mathrm{PCC} / \mathrm{CH}_2 \mathrm{Cl}_2} \mathrm{\mathop {C{H_3}}\limits_{Ethanal} - CHO}$