Practical and Analytical Chemistry — JEE Main PYQs

Consider the following reactions.
${\mathrm{PbCl}}_2+{\mathrm{K}}_2{\mathrm{CrO}}_4\to \mathrm{A}+2\mathrm{KCl}$ (Hot solution)
$\mathrm{A}+\mathrm{NaOH}\rightleftharpoons \mathrm{B}+{\mathrm{Na}}_2{\mathrm{CrO}}_4$ …

In Carius method, 0.75 g of an organic compound gave 1.2 g of barium sulphate, find percentage of sulphur (molar mass $32\mathrm{g}{\mathrm{mol}}^{-1}$). Molar mass of barium sulphate is $233\mathrm{g}{\mathrm{mol}}^{-1}$.

Sodium fusion extract of an organic compound (Y) with ${\mathrm{CHCl}}_3$ and chlorine water gives violet color to the ${\mathrm{CHCl}}_3$ layer. 0.15 g of $(\mathrm{Y})$ gave 0.12 g of the silver halide precipitate in Carius method. Percentage of halogen in the compound …

When 1 g of compound ( X ) is subjected to Kjeldahl's method for estimation of nitrogen, 15 $\mathrm{mL},1\mathrm{M}{\mathrm{H}}_2{\mathrm{SO}}_4$ was neutralized by ammonia evolved. The percentage of nitrogen in compound $(\mathrm{X})$ is :

Identify the correct statements:
A. Hydrated salts can be used as primary standard.
B. Primary standard should not undergo any reaction with air.
C. Reactions of primary standard with another substance should be instantaneous and stoichiometric.
D. Primary standard should not be …

Match List-I with List-II.

List-I: Functional group (detection)
(A) Unsaturation (Baeyer's test)
(B) Alcoholic group (Ceric ammonium nitrate test)
(C) Aldehyde group (Tollen's reagent)
(D) Phenolic group ($\mathrm{FeCl}{}_3$ test)

List-II: Change observed during detection
(I) Red co …

Given below are two statements :

Statement-I : Sublimation is used for the separation and purification of compounds with low melting point.

Statement-II : The boiling point of a liquid increases as the external pressure is reduced.

In the light of the above statements, choose …

x mg of pure HCl was used to make an aqueous solution. 25.0 mL of 0.1 M $\mathrm{Ba}(\mathrm{OH}){}_2$ solution is used when the HCl solution was titrated against it. The numerical value of x is ____ $\times 10^{-1}$. (Nearest integer)
Given : Molar mass of HCl and $\mathrm{Ba}(\mathrm{OH}){}_2$ are 3 …

In Carius method 0.2425 g of an organic compound gave 0.5253 g silver chloride. The percentage of chlorine in the organic compound is

In Dumas method for estimation of nitrogen, 0.50 g of an organic compound gave 70 mL of nitrogen collected at 300 K and 715 mm pressure. The percentage of nitrogen in the organic compound is ______ %
(Aqueous tension at 300 K is 15 mm ).

In the Group analysis of cations, ${\mathrm{Ba}}^{2+}$ & ${\mathrm{Ca}}^{2+}$ are precipitated respectively as

0.25 g of an organic compound "A" containing carbon, hydrogen and oxygen was analysed using the combustion method. There was an increase in mass of ${\mathrm{CaCl}}_2$ tube and potash tube at the end of the experiment. The amount was found to be 0.15 g and 0.1837 g, respectivel …

A student has been given 0.314 g of an organic compound and asked to estimate Sulphur. During the experiment, the student has obtained 0.4813 g of barium sulphate. The percentage of sulphur present in the compound is ______.
(Given Molar mass in $\mathrm{g}{\mathrm{mol}}^{-1}$ S: …

Match List-I with List-II.

List-I (Mixture of Compounds):
A. Diethyl amine + Ethyl amine
B. Acetaldehyde + Acetone
C. Ethanol + Phenol
D. Benzoic acid + Cinnamic acid

List-II (Reagent used to distinguish):
I. Bromine water
II. ${\mathrm{CHCl}}_3+\mathrm{KOH},\Delta$
III. Neutr …

A salt with few drops of conc. HCl gives apple green colour in flame test. The group precipitate of the salt is dissolved in acetic acid and treated with ${\mathrm{K}}_2{\mathrm{CrO}}_4$ to give yellow precipitate. When the sodium carbonate extract of the salt solution is heated …

2.0 g of a bromo hydrocarbon ( X ) was subjected to Carius analysis, gave 3.36 g of AgBr . The percentage of carbon in the compound ( X ) is $26.7\%$. Total number of carbon atoms in the empirical formula for compound ( X ) is ______ .
(Given molar mass in …

Consider the following reactions sequence

When the product (P) is subjected to Carius analysis using ${\mathrm{AgNO}}_3$, 1.0 g of the product (P) will produce ______ g of the precipitate of AgBr. (Nearest integer)
(Given: molar mass in ${\mathrm{g}\mathrm{mol}}^{-1}$ C: 12, H: 1, O: 16, …

Among ${\mathrm{Fe}}^{3+}$, ${\mathrm{Pb}}^{2+}$, ${\mathrm{Cu}}^{2+}$ and ${\mathrm{Mn}}^{2+}$, identify the one that gets precipitated out while passing ${\mathrm{H}}_2\mathrm{S}$ in presence of ${\mathrm{NH}}_4\mathrm{OH}$ as group reagent. The highest possible oxidation state of the …

In sulphur estimation, $2.0\times 10^{-3}\mathrm{mol}$ of an organic compound (X) (molar mass $76{\mathrm{g}\mathrm{mol}}^{-1}$) gave 0.4813 g of barium sulphate (molar mass $233{\mathrm{gmol}}^{-1}$). The percentage of sulphur in the compound (X) is _____ $\times 10^{-1}\%$ (Nearest in …

Statement I : Sodium dichromate and potassium dichromate are classified as primary standard in titrimetric analysis .

Statement II : Phenolphthalein is a weak base, therefore it dissociates in acidic medium.

In the light of the above statements, choose the correct answer from t …

In an estimation of sulphur by Carius method 0.2 g of the substance gave 0.6 g of ${\mathrm{BaSO}}_4$. The percentage of sulphur in the substance is ____ %.
(Given molar mass in $\mathrm{g}{\mathrm{mol}}^{-1}\mathrm{S}:32,{\mathrm{BaSO}}_4:231$ )

Given below are two statements :

Statement I: A mixture of ${\mathrm{C}}_{12}{\mathrm{H}}_{22}{\mathrm{O}}_{11}$ (sugar) and NaCl can be separated by dissolving sugar in alcohol, due to differential solubility
Statement II : Rose essence from rose petals is separated by steam dist …

In Carius method for estimation of halogens, 180 mg of an organic compound produced 143.5 mg of AgCl . The percentage composition of chlorine in the compound is ____ %.
[Given : molar mass in $\mathrm{g}{\mathrm{mol}}^{-1}$ of $\mathrm{Ag}:108$, $\mathrm{Cl}=35.5]$

Given below are two statement :

Statement (I) : Nitrogen, sulphur, halogen and phosphorus present in an organic compound are detected by Lassaigne's Test.

Statement (II) : The elements present in the compound are converted from covalent form into ionic form by fusing the compou …

Given below are two statements I and II.

Statement I : Dumas method is used for estimation of "Nitrogen" in an organic compound.
Statement II : Dumas method involves the formation of ammonium sulphate by heating the organic compound with conc ${\mathrm{H}}_2{\mathrm{SO}}_4$. …

Among the following cations, the number of cations which will give characteristic precipitate in their identification tests with ${\mathrm{K}}_4\left[\mathrm{Fe}(\mathrm{CN}{)}_6\right]$ is : …

Find the compound ' $A$ ' from the following reaction sequences.

In Carius method of estimation of halogen, 0.25 g of an organic compound gave 0.15 g of silver bromide ( AgBr ). The percentage of Bromine in the organic compound is ______ $\times 10^{-1}$ % (Nearest integer).
(Given : Molar mass of Ag is 108 and Br is …

Given below are two statements :

Statement I: In Lassaigne's test, the covalent organic molecules are transformed into ionic compounds.

Statement II : The sodium fusion extract of an organic compound having N and S gives prussian blue colour with ${\mathrm{FeSO}}_4$ and …

During "S" estimation, 160 mg of an organic compound gives 466 mg of barium sulphate. The percentage of Sulphur in the given compound is
____ %.
(Given molar mass in $\mathrm{g}{\mathrm{mol}}^{-1}$ of $\mathrm{Ba}:137,\mathrm{S}:32$, O : 16)

Given below are two statements :

Statement I: In the oxalic acid vs ${\mathrm{KMnO}}_4$ (in the presence of dil ${\mathrm{H}}_2{\mathrm{SO}}_4$) titration the solution needs to be heated initially to $60^{\circ }\mathrm{C}$, but no heating is required in Ferrous ammonium sulpha …

Identify A, B and C in the given below reaction sequence

(1) Ammonium acetate
(2) Acetic acid
(3) ${\mathrm{K}}_2{\mathrm{CrO}}_4$

C → Yellow ppt

The purification method based on the following physical transformation is :

Identify the inorganic sulphides that are yellow in colour :
(A) $({\mathrm{NH}}_4{)}_2\mathrm{S}$
(B) PbS
(C) CuS
(D) ${\mathrm{As}}_2{\mathrm{S}}_3$
(E) ${\mathrm{As}}_2{\mathrm{S}}_5$

Choose the correct answer from the options given below :

The steam volatile compounds among the following are:
(A) (see structure)
(B) (see structure)
(C) (see structure)
(D) (see structure)

Choose the correct answer from the options given below:

Given below are two statements :

Statement (I) : In partition chromatography, stationary phase is thin film of liquid present in the inert support.
Statement (II) : In paper chromatography, the material of paper acts as a stationary phase.
In the light of the above statements, c …

In the sulphur estimation, 0.20 g of a pure organic compound gave 0.40 g of barium sulphate. The percentage of sulphur in the compound is ______
$\times 10^{-1}\%$.
(Molar mass : $\mathrm{O}=16,\mathrm{S}=32,\mathrm{Ba}=137$ in $\mathrm{g}{\mathrm{mol}}^{-1}$ )

Choose the correct tests with respective observations.
(A) ${\mathrm{CuSO}}_4$ (acidified with acetic acid) + ${\mathrm{K}}_4\left[\mathrm{Fe}(\mathrm{CN}{)}_6\right]\to$ Chocolate brown precipitate.
(B) …

Formation of ${\mathrm{Na}}_4\left[\mathrm{Fe}(\mathrm{CN}{)}_5\mathrm{NOS}\right]$, a purple coloured complex formed by addition of sodium nitroprusside in sodium carbonate extract of salt indicates the presence of :

In Dumas' method for estimation of nitrogen, 0.5 gram of an organic compound gave 60 mL of nitrogen collected at 300 K temperature and 715 mm Hg pressure. The percentage composition of nitrogen in the compound (Aqueous tension at $300\mathrm{K}=15\mathrm{mm}\mathrm{Hg}$ ) …

During estimation of nitrogen by Dumas' method of compound X (0.42 g):

_____ mL of ${\mathrm{N}}_2$ gas will be liberated at STP. (nearest integer)
(Given molar mass in $\mathrm{g}{\mathrm{mol}}^{-1}$: C: 12, H: 1, N : 14)

In Dumas' method for estimation of nitrogen 1g of an organic compound gave 150 mL of nitrogen collected at 300 K temperature and 900 mm Hg pressure. The percentage composition of nitrogen in the compound is ____ % (nearest integer).
(Aqueous tension at …

In Dumas' method 292 mg of an organic compound released 50 mL of nitrogen gas ( ${\mathrm{N}}_2$ ) at 300 K temperature and 715 mm Hg pressure. The percentage composition of ' N ' in the organic compound is $\_\_\_\_$ % (Nearest integer)
(Aqueous tension at …

$\mathrm{A}\underset{\text{ (ii) }{\mathrm{H}}_3{\mathrm{O}}^{+}}{\overset{\text{(i) }\mathrm{NaOH}}{\to }}\mathrm{B}\underset{\text{ (ii) }{\mathrm{H}}_2{\mathrm{SO}}_4,\Delta }{\overset{\text{ (i) }\mathrm{EtOH}}{\to }}\mathrm{C}$
'A' shows positive Lassaign's test for N and its molar mass i …

Compounds that should not be used as primary standards in titrimetric analysis are :
A. ${\mathrm{Na}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$
B. Oxalic acid
C. NaOH
D. ${\mathrm{FeSO}}_4\cdot 6{\mathrm{H}}_2\mathrm{O}$
E. Sodium tetraborate

Choose the most appropriate answer from the …

In Dumas' method for estimation of nitrogen 0.4 g of an organic compound gave 60 mL of nitrogen collected at 300 K temperature and 715 mm Hg pressure. The percentage composition of nitrogen in the compound is
(Given : Aqueous tension at …

Match the LIST-I with LIST-II:
LIST-I (Reagent): A. Sodium bicarbonate solution B. Neutral ferric chloride C. Ceric ammonium nitrate D. Alkaline KMnO₄
LIST-II (Functional Group detected): I. Double bond/unsaturation II. Carboxylic acid III. Phenolic -OH IV. Alcoholic -OH …

In the precipitation of the iron group (III) in qualitative analysis, ammonium chloride is added before adding ammonium hydroxide to :

Which of the following nitrogen containing compound does not give Lassaigne's test?

Only 2 mL of KMnO₄ solution of unknown molarity is required to reach the end point of a titration of 20 mL of oxalic acid (2 M) in acidic medium. The molarity of KMnO₄ solution should be ____ M.