Practical and Analytical Chemistry — JEE Main PYQs

Using the given figure, the ratio of $R_f$ values of sample A and sample C is $\mathrm{x}\times 10^{-2}$. Value of x is

Which of the following statements are correct?
A. Glycerol is purified by vacuum distillation because it decomposes at its normal boiling point.
B. Aniline can be purified by steam distillation as aniline is miscible in water.
C. Ethanol can be separated from ethanol water mixtur …

Match List I with List II :
| B. | …

During the detection of acidic radical present in a salt, a student gets a pale yellow precipitate soluble with difficulty in ${\mathrm{NH}}_4\mathrm{OH}$ solution when sodium carbonate extract was first acidified with dil. ${\mathrm{HNO}}_3$ and then ${\mathrm{AgNO}}_3$ s …

The correct statements among the following, for a "chromatography" purification method is:

In qualitative test for identification of presence of phosphorous, the compound is heated with an oxidising agent. Which is further treated with nitric acid and ammonium molybdate respectively. The yellow coloured precipitate obtained is :

Match List-I with List-II.

List-I (Test)
(A) Bayer's test
(B) Ceric ammonium nitrate test
(C) Phthalein dye test
(D) Schiff's test

List-II (Identification)
(I) Phenol
(II) Aldehyde
(III) Alcoholic-OH group
(IV) Unsaturation

Choose the correct answer from the options given belo …

Given below are two statements :

Statement (I) : Kjeldahl method is applicable to estimate nitrogen in pyridine.

Statement (II) : The nitrogen present in pyridine can easily be converted into ammonium sulphate in Kjeldahl method.

In the light of the above statements, choose th …

Methods used for purification of organic compounds are based on :

Identify the incorrect statements regarding primary standard of titrimetric analysis
(A) It should be purely available in dry form.
(B) It should not undergo chemical change in air.
(C) It should be hygroscopic and should react with another chemical instantaneously and stoichiome …

In the given TLC, the distance of spot $\mathrm{A}\&\mathrm{B}$ are $5\mathrm{cm}\&7\mathrm{cm}$, from the bottom of TLC plate, respectively.
$R_f$ value of $B$ is $x\times 10^{-1}$ times more than $A$. The value of $x$ is ____.

Lassaigne's test is used for detection of :

Following Kjeldahl's method, 1g of organic compound released ammonia, that neutralised 10 mL of $2\mathrm{M}{\mathrm{H}}_2{\mathrm{SO}}_4$. The percentage of nitrogen in the compound is ____ %.

In Kjeldahl's method for estimation of nitrogen, ${\mathrm{CuSO}}_4$ acts as :

Given below are two statements:

Statement (I): Potassium hydrogen phthalate is a primary standard for standardisation of sodium hydroxide solution.
Statement (II): In this titration phenolphthalein can be used as indicator.
In the light of the above statements, choose the most a …

The number of white coloured salts among the following is ____
(A) ${\mathrm{SrSO}}_4$
(B) $\mathrm{Mg}({\mathrm{NH}}_4){\mathrm{PO}}_4$
(C) ${\mathrm{BaCrO}}_4$
(D) $\mathrm{Mn}(\mathrm{OH}{)}_2$
(E) ${\mathrm{PbSO}}_4$
(F) ${\mathrm{PbCrO}}_4$
(G) AgBr
(H) ${\mathrm{PbI}}_2$
(I …

Phenolic group can be identified by a positive:

The technique used for purification of steam volatile water immiscible substance is:

Appearance of blood red colour, on treatment of the sodium fusion extract of an organic compound with FeSO₄ in presence of concentrated H₂SO₄ indicates the presence of element/s

A reagent which gives brilliant red precipitate with Nickel ions in basic medium is

On passing a gas, ' X ', through Nessler's reagent, a brown precipitate is obtained. The gas ' X ' is

Chromatographic technique/s based on the principle of differential adsorption is/are
A. Column chromatography
B. Thin layer chromatography
C. Paper chromatography

Choose the most appropriate answer from the options given below:

The compound that is white in color is

'Adsorption' principle is used for which of the following purification method?

Molar mass of the salt from $\mathrm{NaBr},{\mathrm{NaNO}}_3,\mathrm{KI}$ and ${\mathrm{CaF}}_2$ which does not evolve coloured vapours on heating with concentrated ${\mathrm{H}}_2{\mathrm{SO}}_4$ is ____ $\mathrm{g}{\mathrm{mol}}^{-1}$, (Molar mass in …

Given below are two statements:

Statement-I: The gas liberated on warming a salt with dil ${\mathrm{H}}_2{\mathrm{SO}}_4$, turns a piece of paper dipped in lead acetate into black, it is a confirmatory test for sulphide ion.
Statement-II: In statement-I the colour of paper tu …

The Lassiagne's extract is boiled with dil ${\mathrm{HNO}}_3$ before testing for halogens because,

On a thin layer chromatographic plate, an organic compound moved by 3.5 cm, while the solvent moved by 5 cm. The retardation factor of the organic compound is ______ $\times 10^{-1}$

The fragrance of flowers is due to the presence of some steam volatile organic compounds called essential oils. These are generally insoluble in water at room temperature but are miscible with water vapour in vapour phase. A suitable method for the extraction of these oils from t …

Which among the following purification methods is based on the principle of "Solubility" in two different solvents?

Match List I with List II:
LIST-I (Technique): A. Distillation B. Fractional distillation C. Steam distillation D. Distillation under reduced pressure
LIST-II (Application): I. Separation of glycerol from spent-lye II. Aniline–Water mixture III. Separation of crude oil fra …

Element not present in Nessler's reagent is:-

Formation of which complex, among the following, is not a confirmatory test of ${\mathrm{Pb}}^{2+}$ ions

From the figure of column chromatography given below, identify incorrect statements.
A. Compound 'c' is more polar than 'a' and 'b'
B. Compound 'a' is least polar
C. Compound 'b' comes out of the column before 'c' and after 'a'
D. Compound 'a' spends more time in the column
Choos …

In Carius tube, an organic compound 'X' is treated with sodium peroxide to form a mineral acid 'Y'. The solution of ${\mathrm{BaCl}}_2$ is added to 'Y' to form a precipitate 'Z'. 'Z' is used for the quantitative estimation of an extra element. 'X' could be:

Using column chromatography, mixture of two compounds 'A' and 'B' was separated. 'A' eluted first, this indicates 'B' has

When a solution of mixture having two inorganic salts was treated with freshly prepared ferrous sulphate in acidic medium, a dark brown ring was formed whereas on treatment with neutral ${\mathrm{FeCl}}_3$, it gave deep red colour which disappeared on boiling and a brown red ppt …

Thin layer chromatography of a mixture shows the following observation :

Three organic compounds $\mathrm{A},\mathrm{B}$ and C were allowed to run in thin layer chromatography using hexane and gave the following result (see figure). The ${\mathrm{R}}_{\mathrm{f}}$ value of the most polar compound is
$\_\_\_\_$ $\times 10^{-2}$

20 mL of calcium hydroxide was consumed when it was reacted with 10 mL of unknown solution of ${\mathrm{H}}_2{\mathrm{SO}}_4$. Also 20 mL standard solution of 0.5 M HCl containing 2 drops of phenolphthalein was titrated with calcium hydroxide the mixture showed pink colour when …

In the wet tests for detection of various cations by precipitation, ${\mathrm{Ba}}^{2+}$ cations are detected by obtaining precipitate of

0.400 g of an organic compound (X) gave 0.376 g of AgBr in Carius method for estimation of bromine. % of bromine in the compound (X) is ______.
(Given: Molar mass $\mathrm{AgBr}=188{\mathrm{g}\mathrm{mol}}^{-1}$, $\mathrm{Br}=80{\mathrm{g}\mathrm{mol}}^{-1}$)

Which of the following statement is correct for paper chromatography?

Number of isomeric compounds with molecular formula ${\mathrm{C}}_9{\mathrm{H}}_{10}\mathrm{O}$ which
(i) do not dissolve in NaOH
(ii) do not dissolve in HCl.
(iii) do not give orange precipitate with 2, $4-\mathrm{DNP}$
(iv) on hydrogenation give identical compound with mole …

In sulphur estimation, 0.471 g of an organic compound gave 1.4439 g of barium sulphate.

The percentage of sulphur in the compound is ______ (Nearest Integer)
(Given: Atomic mass Ba: $137$ u; S: $32$ u, O: $16$ u)

A chloride salt solution acidified with dil. ${\mathrm{HNO}}_3$ gives a curdy white precipitate, [A], on addition of ${\mathrm{AgNO}}_3$. [A] on treatment with ${\mathrm{NH}}_4\mathrm{OH}$ gives a clear solution, B .

Compound that will give positive Lassaigne's test for both nitrogen and halogen is

Following chromatogram was developed by adsorption of compound 'A' on a 6 cm TLC glass plate. Retardation factor of the compound 'A' is ______ $\times 10^{-1}$.

Which of the following compounds would give the following set of qualitative analysis?
(i) Fehling's Test : Positive
(ii) Na fusion extract upon treatment with sodium nitroprusside gives a blood red colour but not

During the qualitative analysis of ${\mathrm{SO}}_3^{2-}$ using dilute ${\mathrm{H}}_2{\mathrm{SO}}_4,{\mathrm{SO}}_2$ gas is evolved which turns ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ solution (acidified with dilute ${\mathrm{H}}_2{\mathrm{SO}}_4$ ):