Other Chemistry · JEE Main previous year questions

2026 44 questions

1. Q512026 · 8 Apr 2026 · Shift 2

   Match List - I with List - II. $$\begin{array}{llll}\text{List - I}& & \text{List - II}& \\ \text{Mass of substance}& & \text{Number of atoms}& \\ \text{A.}& 1.8\mathrm{mg}\text{water}& \text{I.}& 2\times 10^{-4}\times {\mathrm{N}}_{\mathrm{A}}\\ \text{B.}& 9.8\mathrm{mg}\text{sulphuric acid}& \text{II.}& 1.5\times 10^{-4}\times {\mathrm{N}}_{\mathrm{A}}\\ \text{C.}& 1.8\mathrm{mg}\text{carbon}& \text{III.}& 3\times 10^{-4}\times {\mathrm{N}}_{\mathrm{A}}\\ \text{D.}& 5.85\mathrm{mg}\text{salt }(\mathrm{NaCl})& \text{IV.}& 7\times 10^{-4}\times {\mathrm{N}}_{\mathrm{A}}\end{array}$$ Choose the correct answer from the options given below :

   1. A.A-IV, B-III, C-I, D-II
   2. B.A-III, B-II, C-IV, D-I
   3. C.A-III, B-IV, C-II, D-I
   4. D.A-III, B-IV, C-I, D-II
   Show answer

   Answer: C

2. Q522026 · 6 Apr 2026 · Shift 1

   If shortest wavelength of hydrogen atom in Lyman series is $x$, then longest wavelength in Balmer series of $\mathrm{H}{\mathrm{e}}^{+}$ is:

   1. A.$\frac{9x}{5}$
   2. B.$\frac{36x}{5}$
   3. C.$\frac{x}{4}$
   4. D.$\frac{5x}{9}$
   Show answer

   Answer: A

3. Q542026 · 6 Apr 2026 · Shift 1

   The pairs among $\mathrm{A}=\left[\mathrm{S}{\mathrm{O}}_3^{2-},\mathrm{C}{\mathrm{O}}_3^{2-}\right]$, $\mathrm{B}=\left[{\mathrm{O}}_2^{2-},{\mathrm{F}}_2\right]$, $\mathrm{C}=\left[\mathrm{C}{\mathrm{N}}^{-},\mathrm{CO}\right]$, $\mathrm{D}=\left[\mathrm{N}{\mathrm{H}}_3,{\mathrm{H}}_3{\mathrm{O}}^{+}\right]$ and $\mathrm{E}=\left[\mathrm{Mn}{\mathrm{O}}_4^{2-},\mathrm{Cr}{\mathrm{O}}_4^{2-}\right]$ that do not have similar Lewis dot structure are

   1. A.A, B and E
   2. B.A and E
   3. C.B, C and D
   4. D.C and D
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   Answer: B

4. Q752026 · 6 Apr 2026 · Shift 1· Numerical answer

   Consider the reaction $\mathrm{X}\rightleftharpoons \mathrm{Y}$ at $300\mathrm{K}$. If $\Delta {\mathrm{H}}^{\theta }$ and $\mathrm{K}$ are $28.40\mathrm{kJ}\mathrm{mo}{\mathrm{l}}^{-1}$ and $1.8\times 10^{-7}$ at the same temperature, then the magnitude of $\Delta {\mathrm{S}}^{\theta }$ for the reaction in $\mathrm{J}{\mathrm{K}}^{-1}\mathrm{mo}{\mathrm{l}}^{-1}$ is ____. (Nearest integer) (Given : $\mathrm{R}=8.3\mathrm{J}{\mathrm{K}}^{-1}\mathrm{mo}{\mathrm{l}}^{-1}$, $\ln 10=2.3$, $\log 3=0.48$, $\log 2=0.30$)

   Show answer

   Answer: 34

5. Q512026 · 5 Apr 2026 · Shift 1

   How many grams of residue is obtained by heating $2.76\text{ g}$ of silver carbonate? (Given : Molar mass of $\text{C}$, $\text{O}$ and $\text{Ag}$ are $12$, $16$ and $108{\text{ g mol}}^{-1}$ respectively)

   1. A.$1.08\text{ g}$
   2. B.$2.16\text{ g}$
   3. C.$3.24\text{ g}$
   4. D.$4.32\text{ g}$
   Show answer

   Answer: B

6. Q602026 · 5 Apr 2026 · Shift 1

   Which of the following is NOT a physical or chemical characteristics of interstitial compounds?

   1. A.They have high melting points, higher than those of pure metals.
   2. B.They are very soft and ionic in nature.
   3. C.They retain metallic conductivity.
   4. D.They are chemically inert and usually non-stoichiometric.
   Show answer

   Answer: B

7. Q552026 · 5 Apr 2026 · Shift 2

   The $\underline{\text{correct}}$ order of molar heat capacities measured at $298\mathrm{K}$ and $1\mathrm{bar}$ is :

   1. A.$\mathrm{Copper}(\mathrm{s})>\mathrm{Bromine}(\mathrm{l})>\mathrm{Helium}(\mathrm{g})$
   2. B.$\mathrm{Bromine}(\mathrm{l})>\mathrm{Copper}(\mathrm{s})>\mathrm{Helium}(\mathrm{g})$
   3. C.$\mathrm{Helium}(\mathrm{g})>\mathrm{Bromine}(\mathrm{l})>\mathrm{Copper}(\mathrm{s})$
   4. D.$\mathrm{Helium}(\mathrm{g})>\mathrm{Bromine}(\mathrm{l})=\mathrm{Copper}(\mathrm{s})$
   Show answer

   Answer: B

8. Q572026 · 5 Apr 2026 · Shift 2

   One half cell in a voltaic cell is constructed by dipping silver rod in $\mathrm{AgN}{\mathrm{O}}_3$ solution of unknown concentration, other half cell is $\mathrm{Zn}$ rod dipped in $1\text{molar}$ solution of $\mathrm{ZnS}{\mathrm{O}}_4$. A voltage of $1.60\mathrm{V}$ is measured at $298\mathrm{K}$ for this cell. What is the concentration of ${\mathrm{Ag}}^{+}$ ions used in terms of $\log x(x=[{\mathrm{Ag}}^{+}])$ ? $${\mathrm{E}}_{\mathrm{Z}{\mathrm{n}}^{2+}/Zn}^{\ominus }=-0.76V,{\mathrm{E}}_{\mathrm{A}{\mathrm{g}}^{+}/Ag}^{\ominus }=+0.80V,\frac{2.303\mathrm{RT}}{\mathrm{F}}=0.059\mathrm{V}$$

   1. A.$\frac{2}{3.9}$
   2. B.$\frac{4}{5.9}$
   3. C.$\frac{2.9}{2}$
   4. D.$\frac{5.9}{4}$
   Show answer

   Answer: B

9. Q522026 · 4 Apr 2026 · Shift 1

   What is the ratio of wave number of first line (lowest energy line) of Balmer series of H atomic spectrum to first line of its Brackett series?

   1. A.$5:1$
   2. B.$5:0.81$
   3. C.$5:1.75$
   4. D.$5:27$
   Show answer

   Answer: B

10. Q632026 · 4 Apr 2026 · Shift 1

    Increasing order of electron withdrawing power of following functional groups is: a. $-\mathrm{CN}$ b. $-\mathrm{COOH}$ c. $-\mathrm{N}{\mathrm{O}}_2$ d. $-\mathrm{I}$

    1. A.$\mathrm{c}<\mathrm{b}<\mathrm{d}<\mathrm{a}$
    2. B.$\mathrm{c}<\mathrm{a}<\mathrm{b}<\mathrm{d}$
    3. C.$\mathrm{d}<\mathrm{b}<\mathrm{a}<\mathrm{c}$
    4. D.$\mathrm{a}<\mathrm{b}<\mathrm{c}<\mathrm{d}$
    Show answer

    Answer: C

11. Q662026 · 4 Apr 2026 · Shift 1
    
    1. A.5
    2. B.4
    3. C.6
    4. D.3
    Show answer

    Answer: A

12. Q702026 · 4 Apr 2026 · Shift 1
    
    1. A.Violet
    2. B.Green
    3. C.Red
    4. D.Colourless
    Show answer

    Answer: D

13. Q632026 · 4 Apr 2026 · Shift 2
    
    1. A.The order of all the three reactions is same.
    2. B.The rate constant of reaction 3 is larger than the rate constant of reaction 2 if the order of reaction is same for both.
    3. C.The SI unit of rate constant of reaction 1 is ${\mathrm{s}}^{-1}$.
    4. D.Thermal decomposition of $\mathrm{HI}$ on gold surface is an example of reaction 2.
    Show answer

    Answer: B

14. Q652026 · 4 Apr 2026 · Shift 2
    
    1. A.enantiomers.
    2. B.identical molecules.
    3. C.diastereomers.
    4. D.meso compounds.
    Show answer

    Answer: B

15. Q662026 · 4 Apr 2026 · Shift 2
    
    1. A.B > D > E > A > C
    2. B.D > B > E > A > C
    3. C.C > A > B > D > E
    4. D.D > E > B > A > C
    Show answer

    Answer: D

16. Q612026 · 2 Apr 2026 · Shift 1

    Which of the following sets includes all the species that will change the orange colour of ${\mathrm{K}}_2\mathrm{C}{\mathrm{r}}_2{\mathrm{O}}_7$ in acidic medium ?

    1. A.$\mathrm{F}{\mathrm{e}}^{2+},\mathrm{S}{\mathrm{n}}^{2+},{\mathrm{I}}^{-},{\mathrm{S}}^{2-}$
    2. B.${\mathrm{S}}^{2-},\mathrm{F}{\mathrm{e}}^{3+},{\mathrm{I}}^{-},{\mathrm{C}}_2{\mathrm{O}}_4^{2-}$
    3. C.$\mathrm{F}{\mathrm{e}}^{2+},\mathrm{N}{\mathrm{O}}_2^{-},\mathrm{S}{\mathrm{O}}_2,\mathrm{S}{\mathrm{n}}^{4+}$
    4. D.$\mathrm{F}{\mathrm{e}}^{3+},\mathrm{S}{\mathrm{O}}_4^{2-},{\mathrm{S}}^{2-},\mathrm{S}{\mathrm{n}}^{4+}$
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    Answer: A

17. Q652026 · 2 Apr 2026 · Shift 1

    For a thin symmetric prism made of glass (refractive index 1.5), the ratio of incident angle and minimum deviation will be _______.

    1. A.3 : 4
    2. B.3 : 2
    3. C.2 : 1
    4. D.1 : 2
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    Answer: C

18. Q522026 · 2 Apr 2026 · Shift 2

    The first and second ionization constants of a weak dibasic acid ${\mathrm{H}}_2\mathrm{A}$ are $8.1\times 10^{-8}$ and $1.0\times 10^{-13}$ respectively. $0.1\mathrm{mol}$ of ${\mathrm{H}}_2\mathrm{A}$ was dissolved in $1\mathrm{L}$ of $0.1\mathrm{M}$ $\mathrm{HCl}$ solution. The concentration of $\mathrm{H}{\mathrm{A}}^{-}$ in the resultant solution is :

    1. A.$0.1\mathrm{M}$
    2. B.$9.53\times 10^{-6}\mathrm{M}$
    3. C.$8.1\times 10^{-8}\mathrm{M}$
    4. D.$1.0\times 10^{-13}\mathrm{M}$
    Show answer

    Answer: C

19. Q582026 · 2 Apr 2026 · Shift 2

    The correct set that contains all kinds (basic, acidic, amphoteric and neutral) of oxides is :

    1. A.$\mathrm{N}{\mathrm{a}}_2\mathrm{O}$, ${\mathrm{K}}_2\mathrm{O}$, $\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3$ and $\mathrm{A}{\mathrm{s}}_2{\mathrm{O}}_3$
    2. B.$\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3$, $\mathrm{A}{\mathrm{s}}_2{\mathrm{O}}_3$, $\mathrm{CO}$ and $\mathrm{NO}$
    3. C.${\mathrm{K}}_2\mathrm{O}$, $\mathrm{C}{\mathrm{l}}_2{\mathrm{O}}_7$, $\mathrm{A}{\mathrm{s}}_2{\mathrm{O}}_3$ and $\mathrm{NO}$
    4. D.$\mathrm{N}{\mathrm{a}}_2\mathrm{O}$, ${\mathrm{N}}_2\mathrm{O}$, $\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3$ and $\mathrm{CO}$
    Show answer

    Answer: C

20. Q672026 · 2 Apr 2026 · Shift 2
    
    1. A.A, B and C Only
    2. B.B and C Only
    3. C.C and D Only
    4. D.A and D Only
    Show answer

    Answer: D

21. Q722026 · 2 Apr 2026 · Shift 2· Numerical answer

    Consider the following gas phase reaction being carried out in a closed vessel at $25^{\circ }\text{C}$. $$2\mathrm{A}(g)⟶4\mathrm{B}(g)+\mathrm{C}(g)$$ | time (min) | total pressure of the system (mm Hg) | | :---: | :---: | | 30 | 300 | | $\infty$ | 600 | The pressure of $\mathrm{C}(g)$ at 30 minutes time interval would be ________ $\text{mm Hg}$. (nearest integer)

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    Answer: 20

22. Q632026 · 28 Jan 2026 · Shift 1

    CORRECT order of stability for the following is $\mathrm{C}{\mathrm{H}}_2=\mathrm{C}{\mathrm{H}}^{-}$ , $\mathrm{C}{\mathrm{H}}_3-\mathrm{C}{\mathrm{H}}_2^{-}$ , $\mathrm{CH}\equiv {\mathrm{C}}^{-}$

    1. A.$\mathrm{CH}\equiv {\mathrm{C}}^{-}>\mathrm{C}{\mathrm{H}}_3-\mathrm{C}{\mathrm{H}}_2^{-}>\mathrm{C}{\mathrm{H}}_2=\mathrm{C}{\mathrm{H}}^{-}$
    2. B.$\mathrm{C}{\mathrm{H}}_2=\mathrm{C}{\mathrm{H}}^{-}>\mathrm{CH}\equiv {\mathrm{C}}^{-}>\mathrm{C}{\mathrm{H}}_3-\mathrm{C}{\mathrm{H}}_2^{-}$
    3. C.$\mathrm{CH}\equiv {\mathrm{C}}^{-}>\mathrm{C}{\mathrm{H}}_2=\mathrm{C}{\mathrm{H}}^{-}>\mathrm{C}{\mathrm{H}}_3-\mathrm{C}{\mathrm{H}}_2^{-}$
    4. D.$\mathrm{C}{\mathrm{H}}_3-\mathrm{C}{\mathrm{H}}_2^{-}>\mathrm{C}{\mathrm{H}}_2=\mathrm{C}{\mathrm{H}}^{-}>\mathrm{CH}\equiv {\mathrm{C}}^{-}$
    Show answer

    Answer: C

23. Q692026 · 28 Jan 2026 · Shift 1

    The correct statement among the following is:

    1. A.$[\mathrm{Ni}(\mathrm{CN}{)}_4{]}^{2-}$ and $[\mathrm{NiC}{\mathrm{l}}_4{]}^{2-}$ are diamagnetic and $\mathrm{Ni}(\mathrm{CO}{)}_4$ is paramagnetic.
    2. B.$\mathrm{Ni}(\mathrm{CO}{)}_4$ is diamagnetic and $[\mathrm{NiC}{\mathrm{l}}_4{]}^{2-}$ and $[\mathrm{Ni}(\mathrm{CN}{)}_4{]}^{2-}$ are paramagnetic.
    3. C.$\mathrm{Ni}(\mathrm{CO}{)}_4$ and $[\mathrm{NiC}{\mathrm{l}}_4{]}^{2-}$ are diamagnetic and $[\mathrm{Ni}(\mathrm{CN}{)}_4{]}^{2-}$ is paramagnetic.
    4. D.$\mathrm{Ni}(\mathrm{CO}{)}_4$ and $[\mathrm{Ni}(\mathrm{CN}{)}_4{]}^{2-}$ are diamagnetic and $[\mathrm{NiC}{\mathrm{l}}_4{]}^{2-}$ is paramagnetic.
    Show answer

    Answer: D

24. Q572026 · 28 Jan 2026 · Shift 2
    
    1. A.
    2. B.
    3. C.
    4. D.
    Show answer

    Answer: A

25. Q612026 · 28 Jan 2026 · Shift 2

    For the given reaction; ${\text{CaCO}}_3+2\text{HCl}\to {\text{CaCl}}_2+{\text{H}}_2\text{O}+{\text{CO}}_2$ If 90 g ${\text{CaCO}}_3$ is added to 300 mL of HCl which contains 38.55% HCl by mass and has density $1.13{\text{ g mL}}^{-1}$, then which of the following option is correct? Given molar mass of H, Cl, Ca and O are 1, 35.5, 40 and $16{\text{ g mol}}^{-1}$ respectively.

    1. A.64.97 g of HCl remains unreacted
    2. B.60.32 g of HCl remains unreacted
    3. C.32.85 g of ${\text{CaCO}}_3$ remains unreacted
    4. D.97.30 g of HCl reacted
    Show answer

    Answer: A