1
JEE Main 2025 (Online) 28th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The incorrect decreasing order of atomic radii is

A
$\mathrm{Si}>\mathrm{P}>\mathrm{Cl}>\mathrm{F}$
B
$\mathrm{Mg}>\mathrm{Al}>\mathrm{C}>\mathrm{O}$
C
$\mathrm{Al}>\mathrm{B}>\mathrm{N}>\mathrm{F}$
D
$\mathrm{Be}>\mathrm{Mg}>\mathrm{Al}>\mathrm{Si}$
2
JEE Main 2025 (Online) 28th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

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

A
$4.43 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$
B
$3.72 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$
C
$5.12 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$
D
$1.86 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$
3
JEE Main 2025 (Online) 28th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

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 $2-3 \mathrm{atmosphere}$ pressure produces glucose.

In the light of the above statements, choose the correct answer from the options given below

A
Statement I is true but Statement II is false
B
Both Statement I and Statement II are true
C
Statement I is false but Statement II is true
D
Both Statement I and Statement II are false
4
JEE Main 2025 (Online) 28th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

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

A
$\log \left(\frac{1-x}{x}\right)$
B
$0$
C
$\log (1+2 \mathrm{x})$
D
$\log \left(\frac{x}{1-x}\right)$
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