Practical Organic Chemistry - Organic Chemistry - Chemistry Previous Year Questions

Consider the following reaction.

On estimation of bromine in $1.00 \mathrm{~g}$ of $\mathbf{R}$ using Carius method, the amount of $\mathrm{AgBr}$ formed (in $\mathrm{g}$ ) is ___________.

[Given: Atomic mass of $\mathrm{H}=1, \mathrm{C}=12, \mathrm{O}=16, \mathrm{P}=31, \mathrm{Br}=80, \mathrm{Ag}=108]$

The weight percentage of hydrogen in $\mathbf{Q}$, formed in the following reaction sequence, is ________.

[Given: Atomic mass of $\mathrm{H}=1, \mathrm{C}=12, \mathrm{~N}=14, \mathrm{O}=16, \mathrm{~S}=32, \mathrm{Cl}=35$ ]

The reaction of 4-methyloct-1-ene $(\mathbf{P}, 2.52 \mathrm{~g})$ with $\mathrm{HBr}$ in the presence of $\left(\mathrm{C}_6 \mathrm{H}_5 \mathrm{CO}\right)_2 \mathrm{O}_2$ gives two isomeric bromides in a $9: 1$ ratio, with a combined yield of $50 \%$. Of these, the entire amount of the primary alkyl bromide was reacted with an appropriate amount of diethylamine followed by treatment with aq. $\mathrm{K}_2 \mathrm{CO}_3$ to give a non-ionic product $\mathbf{S}$ in $100 \%$ yield.

The mass (in mg) of $\mathbf{S}$ obtained is ________.

[Use molar mass (in $\mathrm{g} \mathrm{mol}^{-1}$ ) : $\mathrm{H}=1, \mathrm{C}=12, \mathrm{~N}=14, \mathrm{Br}=80$ ]

Match the compounds in List-I with the appropriate observations in List-II and choose the correct option.

List–I	List–II
(P)	(1) Reaction with phenyl diazonium salt gives yellow dye.
(Q)	(2) Reaction with ninhydrin gives purple color and it also reacts with FeCl3 to give violet color.
(R)	(3) Reaction with glucose will give corresponding hydrazone.
(S)	(4) Lassiagne extract of the compound treated with dilute HCl followed by addition of aqueous $\mathrm{FeCl}_3$ gives blood red color.
	(5) After complete hydrolysis, it will give ninhydrin test and it DOES NOT give positive phthalein dye test.

Consider the following reaction sequence in which $\mathbf{J}, \mathbf{K}, \mathbf{L}$ and $\mathbf{M}$ are the major products.

Given:

Atomic mass (in amu) : $\mathrm{H}: 1, \mathrm{C}: 12, \mathrm{~N}: 14, \mathrm{O}: 16, \mathrm{~S}: 32, \mathrm{Br}: 80, \mathrm{Ba}: 137$

The volume of 1 M aqueous $\mathrm{H}_2 \mathrm{SO}_4$ required to completely neutralize the ammonia evolved from 5.72 g of $\mathbf{L}$ in Kjeldahl's method of nitrogen estimation is $\_\_\_\_$ mL .

Consider the following reaction sequence in which $\mathbf{J}, \mathbf{K}, \mathbf{L}$ and $\mathbf{M}$ are the major products.

Given :

Atomic mass (in amu) : $\mathrm{H}: 1, \mathrm{C}: 12, \mathrm{~N}: 14, \mathrm{O}: 16, \mathrm{~S}: 32, \mathrm{Br}: 80, \mathrm{Ba}: 137$

In sulphur estimation by Carius method, the amount of $\mathrm{BaSO}_4$ formed from 3.79 g of $\mathbf{M}$ is $\_\_\_\_$ g.