JEE Main 2025 Question Paper (28-Jan-2025) (Shift 1)

Question 1

The incorrect decreasing order of atomic radii is :

Accepted Answer

Be > Mg > Al > Si

Answer

Mg > Al > C > O

Answer

Al > B > N > F

Answer

Si > P > CI > F

Question 2

Given below are two statements : Statement I : In the oxalic acid vs KMnO$_{4}$ (in the presence of dil H$_{2}$SO$_{4}$) titration, the solution needs to be heated initially to 60&deg;C, but no heating is required in Ferrous ammonium sulphate (FAS) vs KMnO$_{4}$ titration (in the presence of dil H$_{2}$SO$_{4}$). Statement II : In oxalic acid vs KMnO$_{4}$ titration, the initial formation of MnSO$_{4}$ takes place at high temperature, which then acts as a catalyst for further reaction. In the case of FAS vs KMnO$_{4}$, heating oxidizes Fe$^{2+}$ into 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 :

Accepted Answer

Both Statement I and Statement II are true

Answer

Statement I is false but Statement II is true

Answer

Statement I is true but Statement II is false

Answer

Both Statement I and Statement II are false

Question 3

Match the List-I with List-IIList-I(Redox Reaction)List-II(Type of Redox Reaction)A$ \mathrm{CH}_{4(g)} + 2\mathrm{O}_{2(g)} \stackrel{\Delta}{	o} \mathrm{CO}_{2(g)} + 2\mathrm{H}_{2}\mathrm{O}_{I} $ (I)Disproportionation reaction B$ 2\mathrm{NaH}_{(s)} \stackrel{\Delta}{	o} 2\mathrm{Na}_{(s)} + H_{2(g)}$ (II)Combination reaction C$ \mathrm{V}_{2}\mathrm{O}_{5(s)} + 5\mathrm{Ca}_{(s)} \stackrel{\Delta}{	o} 2\mathrm{V}_{(s)} + 5\mathrm{CaO}_{(s)} $ (III)Decomposition reaction D$ 2\mathrm{H}_{2}\mathrm{O}_{2(aq)} \stackrel{\Delta}{	o} 2\mathrm{H}_{2(I)}\mathrm{O}(l) + \mathrm{O}_{2(g)} $ (IV)Displacement reactionChoose the correct answer from the options given below :

Accepted Answer

A-II, B-III, C-IV, D-I

Answer

A-II, B-III, C-I, D-IV

Answer

A-III, B-IV, C-I, D-II

Answer

A-IV, B-I, C-II, D-II

Question 4

Given below are two statements:Statement I:   will undergo alkyne hydrolysis at a faster rate than Statement II: In    , intramolecular substitution takes place first by involving a lone pair of electrons on nitrogen. In the light of the above statements, choose the most appropriate answers from the options given below

Accepted Answer

Both Statement I and Statement II are correct

Answer

Both Statement I and Statement II are incorrect

Answer

Statement I is incorrect but statement II is correct.

Answer

Statement I is correct but Statement II is incorrect

Question 5

A weak acid HA has degree of dissociation $ x $. Which option gives the correct expression of $\mathrm{pH} = \mathrm{p}K_{a}$?

Accepted Answer

$ \log\left(\frac{x}{1 - x}\right)$

Answer

$ \log (1 + 2x) $

Answer

$ \log\left(\frac{1 - x}{x}\right)$

Answer

$0$

List-I (Redox Reaction)		List-II (Type of Redox Reaction)
A	$ \mathrm{CH}_{4(g)} + 2\mathrm{O}_{2(g)} \stackrel{\Delta}{\to} \mathrm{CO}_{2(g)} + 2\mathrm{H}_{2}\mathrm{O}_{I} $	(I)	Disproportionation reaction
B	$ 2\mathrm{NaH}_{(s)} \stackrel{\Delta}{\to} 2\mathrm{Na}_{(s)} + H_{2(g)}$	(II)	Combination reaction
C	$ \mathrm{V}_{2}\mathrm{O}_{5(s)} + 5\mathrm{Ca}_{(s)} \stackrel{\Delta}{\to} 2\mathrm{V}_{(s)} + 5\mathrm{CaO}_{(s)} $	(III)	Decomposition reaction
D	$ 2\mathrm{H}_{2}\mathrm{O}_{2(aq)} \stackrel{\Delta}{\to} 2\mathrm{H}_{2(I)}\mathrm{O}(l) + \mathrm{O}_{2(g)} $	(IV)	Displacement reaction