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Chemistry

The metal ion whose electronic configuration is not affected by the nature of the ligand and which gives a violet colour in non-luminous flame under hot condition in borax bead test is:

52.

For a given reaction $ R \rightarrow P $, $ t_{1/2} $ is related to $ [A]_{0} $ as given in table. [Given : $ \log 2 = 0.30 $]
Which of the following is true?

53.

Consider $ 'n' $ is the number of lone pair of electrons present in the equatorial position of the most stable structure of $ \mathrm{ClF_{3}} $. The ions from the following with $ 'n' $ number of unpaired electrons are:
A. $ \mathrm{V}^{3+} $ B. $ \mathrm{Ti}^{3+} $ C. $ \mathrm{Cu}^{2+} $ D. $ \mathrm{Ni}^{2+} $ E. $ \mathrm{Ti}^{2+} $
Choose the correct answers from the options given below:
($ 1 $) A and C Only ($ 2 $) B and D Only ($ 3 $) A, D and E Only ($ 4 $) B and C Only

54.

Given below are two statements:
Statement I: In the oxalic acid vs $ \mathrm{KMnO_4} $ (in the presence of dil. $ \mathrm{H_2SO_4} $) titration the solution needs to be heated initially to $ 60^\circ \mathrm{C} $, but no heating is required in Ferrous ammonium sulphate (FAS) vs $ \mathrm{KMnO_4} $ titration (in the presence of dil. $ \mathrm{H_2SO_4} $).
Statement II: In oxalic acid vs $ \mathrm{KMnO_4} $ titration, the initial formation of $ \mathrm{MnSO_4} $ takes place at high temperature, which then acts as catalyst for further reaction. In the case of FAS vs $ \mathrm{KMnO_4} $, heating oxidizes $ \mathrm{Fe^{2+}} $ into $ \mathrm{Fe^{3+}} $ by oxygen of air and error may be introduced in the experiment.
In the light of the above statements, choose the correct answer from the options given below:

55.

The compounds that produce $ \mathrm{CO_2} $ with aqueous $ \mathrm{NaHCO_3} $ solution are:

56.

Given below are two statements:

Statement-I : will undergo alkaline hydrolysis at a faster rate than

Statement-II : intramolecular substitution takes place first by involving lone pair of electrons on nitrogen.

In the light of the above statements, choose the most appropriate answer
from the options given below:

57.

A molecule (“P”) on treatment with acid undergoes rearrangement and gives (“Q”). (“Q”) on ozonolysis followed by reflux under alkaline condition gives (“R”). The structure of (“R”) is given below:

The structure of (“P”) is:

58.

Given below are two statements:
Statement I : D-glucose pentaacetate reacts with $ 2,4 $-dinitrophenylhydrazine.
Statement II : Starch, on heating with concentrated sulfuric acid at $ 100^\circ \mathrm{C} $ and $ 2\text{–}3 $ atmosphere pressure produces glucose.
In the light of the above statements, choose the correct answer from the options given below:

59.

In a multielectron atom, which of the following orbitals described by three quantum numbers will have same energy in absence of electric and magnetic fields?
A. $ n = 1, \, \ell = 0, \, m_1 = 0 $ B. $ n = 2, \, \ell = 0, \, m_1 = 0 $
C. $ n = 2, \, \ell = 1, \, m_1 = 1 $ D. $ n = 3, \, \ell = 2, \, m_1 = 1 $
E. $ n = 3, \, \ell = 2, \, m_1 = 0 $
Choose the correct answer from the options given below:

60.

A weak acid $ \mathrm{HA} $ has degree of dissociation $ x $. Which option gives the correct expression of $ (\mathrm{pH} - \mathrm{p}K_a) $?

61.

The incorrect decreasing order of atomic radii is:

62.

The products A and B in the following reactions, respectively are:
$ A \xleftarrow{\mathrm{AgNO_2}} \\ \mathrm{CH_3-CH_2-CH_2-Br} \\ \xrightarrow{\mathrm{AgCN}} B $

63.

The correct order of stability of following carbocations is:

64.

Both acetaldehyde and acetone (individually) undergo which of the following reactions?
$ \mathrm{A.} $ Iodoform Reaction $ \mathrm{B.} $ Cannizzaro Reaction $ \mathrm{C.} $ Aldol Condensation $ \mathrm{D.} $ Tollen’s Test $ \mathrm{E.} $ Clemmensen Reduction
Choose the correct answer from the options given below:

65.

The molecules having square pyramidal geometry are:

66.

Match the List-I with List-II.

Choose the correct answer from the options given below:

67.

Ice and water are placed in a closed container at a pressure of $ 1 \, \text{atm} $ and temperature $ 273.15 \, \text{K} $. If pressure of the system is increased $ 2 $ times, keeping temperature constant, then identify correct observation from following:

68.

What is the freezing point depression constant of a solvent, $ 50 \, \mathrm{g} $ of which contain $ 1 \, \mathrm{g} $ non-volatile solute (molar mass $ 256 \, \mathrm{g\,mol^{-1}} $) and the decrease in freezing point is $ 0.40 \, \mathrm{K} $?

69.

Which of the following oxidation reactions are carried out by both $ \mathrm{K_2Cr_2O_7} $ and $ \mathrm{KMnO_4} $ in acidic medium?
A. $ \mathrm{I^- \rightarrow I_2} $ B. $ \mathrm{S^{2-} \rightarrow S} $ C. $ \mathrm{Fe^{2+} \rightarrow Fe^{3+}} $

D. $ \mathrm{I^- \rightarrow IO_3^-} $ E. $ \mathrm{S_2O_3^{2-} \rightarrow SO_4^{2-}} $
Choose the correct answer from the options given below:

70.

Consider the following elements $ \mathrm{In} $, $ \mathrm{Tl} $, $ \mathrm{Al} $, $ \mathrm{Pb} $, $ \mathrm{Sn} $ and $ \mathrm{Ge} $.
The most stable oxidation states of elements with highest and lowest first ionisation enthalpies, respectively, are:

71.

Given below is the plot of the molar conductivity vs $ \sqrt{\text{concentration}} $ for $ \mathrm{KCl} $ in aqueous solution.

If, for the higher concentration of $ \mathrm{KCl} $ solution, the resistance of the conductivity cell is $ 100 \, \Omega $, then the resistance of the same cell with the dilute solution is ‘$ x $’ $ \Omega $. The value of $ x $ is ______. (Nearest integer)

72.

The molarity of a $ 70\% $ (mass/mass) aqueous solution of a monobasic acid (X) is ______ $ \times 10^{-1} $ $ \mathrm{M} $. (Nearest integer)
[Given: Density of aqueous solution of (X) is $ 1.25 \, \mathrm{g\, mL^{-1}} $. Molar mass of the acid is $ 70 \, \mathrm{g\, mol^{-1}} $]

73.

Quantitative analysis of an organic compound (X) shows following $ \% $ composition. C : $ 14.5\% $ Cl : $ 64.46\% $ H : $ 1.8\% $
(Empirical formula mass of the compound (X) is ______ $ \times 10^{-1} $ )
[Given molar mass in $ \mathrm{g\, mol^{-1}} $ of C : $ 12 $ , H : $ 1 $ , O : $ 16 $ , Cl : $ 35.5 $]

74.

Consider the following sequence of reactions:

$ 11.25 \, \mathrm{mg} $ of chlorobenzene will produce ______ $ \times 10^{-1} \, \mathrm{mg} $ of product B. (Consider the reactions result in complete conversion)
[Given molar mass of C, H, O, N and Cl as $ 12 $, $ 1 $, $ 16 $, $ 14 $ and $ 35.5 \, \mathrm{g\, mol^{-1}} $ respectively]

75.

The formation enthalpies, $\Delta\text{H}_\text{f}^\ominus$ for $\text{H(g)}$ and $\text{O(g)}$ are $220.0$ and $250.0\text{ kJ mol}^{-1}$, respectively, at $298.15\text{ K}$, and $\Delta\text{H}_\text{f}^\ominus$ for $\text{H}_2\text{O(g)}$ is $-242.0\text{ kJ mol}^{-1}$ at the same temperature. The average bond enthalpy of the $\text{O}-\text{H}$ bond in water at $298.15\text{ K}$ is $\underline{\qquad}\text{ kJ mol}^{-1}$. (Nearest integer)

JEE Main 2025 28th Jan Morning Shift

Mathematics Physics Chemistry

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Consider the following elements $ \mathrm{In} $, $ \mathrm{Tl} $, $ \mathrm{Al} $, $ \mathrm{Pb} $, $ \mathrm{Sn} $ and $ \mathrm{Ge} $.
The most stable oxidation states of elements with highest and lowest first ionisation enthalpies, respectively, are:

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