While separating a mixture of ortho and para nitrophenols by steam distiliation, name the isomer whịch will be steam volatile. Give reason.

The most suitable method of separation of amixture of ortho and para nitrophenols mixed in the ratio of 1:1 is

The structure of o-nitrophenol and p-nitrophenol are shown in the figure. The former is a steam volatile liquid whereas the letter is a solid. Justify your answer giving reason.

Justify the following statements. i. Water mixed with formic acid cannot be separated by fractional distillation. ii. o -nitrophenol is steam volatile while p-nitrophenol is not. iii. Freshly prepared FeSO_4 solution is insisted during the test for nitrogen in Lassaignes test. iv. Copper spiral is used in the apparatus for Dumas method.

Paragraph Carboxylic acids are distinctly acidic because they ionize in water to give hydronium ions: RCOOH+H_(2)O hArr RCOO^(-) +H_(3)O^(+) The acidic strength depends upon the extent of ionizations of the acid and the stability of the anion formed. The acidic strength can also be expressed in terms of dissociation constant K_(a) or pK_(a) which are related as pK_(a)= -log K_(a) . Most unsubstituted carboxylic acids have K_(a) values in the range of 10^(-4) to 10^(-5) (pK_(a) =4-5) . The substitutents have marked effect on the acidic strength of carboxylic acids. Any group that stabilizes the carboxylate ion more than the carboxylic acid group will increase the acidic strength, and the group which destabilizes the carboxylate group more than the carboxylic acid group will decrease the acidic strength. In a similar manner, the electron-releasing groups makes benzoic acid weaker, while the electron-withdrawing groups make benzoic acid stronger. The ortho isomer of every substituted benzoic acid (whether electron releasing or electron withdrawing) is the strongest among the three isomers due to ortho effect. Which of the following is the weakest acid?

Paragraph Carboxylic acids are distinctly acidic because they ionize in water to give hydronium ions: RCOOH+H_(2)O hArr RCOO^(-) +H_(3)O^(+) The acidic strength depends upon the extent of ionizations of the acid and the stability of the anion formed. The acidic strength can also be expressed in terms of dissociation constant K_(a) or pK_(a) which are related as pK_(a)= -log K_(a) . Most unsubstituted carboxylic acids have K_(a) values in the range of 10^(-4) to 10^(-5) (pK_(a) =4-5) . The substitutents have marked effect on the acidic strength of carboxylic acids. Any group that stabilizes the carboxylate ion more than the carboxylic acid group will increase the acidic strength, and the group which destabilizes the carboxylate group more than the carboxylic acid group will decrease the acidic strength. In a similar manner, the electron-releasing groups makes benzoic acid weaker, while the electron-withdrawing groups make benzoic acid stronger. The ortho isomer of every substituted benzoic acid (whether electron releasing or electron withdrawing) is the strongest among the three isomers due to ortho effect. Which of the following statement is not correct?

Toulene reacts with bromine and iron to give a mixture of three isomeric monobromo products, while with bromine in light it gives exclusively the fourth isomer. Justify the observation.