s-block – JEE Main Previous Year Questions with Solutions

JEE Main Previous Year Papers Questions of Chemistry With Solutions are available at eSaral.



Previous Years AIEEE/JEE Mains Questions

Q. The products obtained on heating $\mathrm{LiNO}_{3}$ will be :-

(1) $\mathrm{LiNO}_{2}+\mathrm{O}_{2}$

(2) $\mathrm{Li}_{2} \mathrm{O}+\mathrm{NO}_{2}+\mathrm{O}_{2}$

(3) $\mathrm{Li}_{3} \mathrm{N}+\mathrm{O}_{2}$

(4) $\mathrm{Li}_{2} \mathrm{O}+\mathrm{NO}+\mathrm{O}_{2}$


Sol. (2)

Fact based.

Q. What is the best description of the change that occurs when $\mathrm{Na}_{2} \mathrm{O}(\mathrm{s})$ is dissolved in water ?

(1) Oxidation number of sodium decreases

(2) Oxide ion accepts sharing in a pair of electrons

(3) Oxide ion donates a pair of electrons

(4) Oxidation number of oxygen increases

Sol. (3)

$\mathrm{O}^{-2}+\mathrm{H}^{\ominus} \rightarrow \mathrm{O}-\mathrm{H}\left\{\mathrm{O}^{-2} \rightarrow \mathrm{H}^{\ominus}\right\}$

Q. Which of the following on thermal-decomposition yields a basic as well as an acidic oxide ?

(1) $\mathrm{NH}_{4} \mathrm{NO}_{3}$

(2) NaNO $_{3}$

(3) $\mathrm{KClO}_{3}$

(4) CaCO $_{3}$


Sol. (4)

Q. Fire extinguishers contain $\mathrm{H}_{2} \mathrm{SO}_{4}$ and which one of the following :-

(1) $\mathrm{CaCO}_{3}$

(2) $\mathrm{NaHCO}_{3}$ and $\mathrm{Na}_{2} \mathrm{CO}_{3}$

(3) $\mathrm{Na}_{2} \mathrm{CO}_{3}$

(4) $\mathrm{NaHCO}_{3}$

[JEE MAIN-2012, Online]

Sol. (4)

Solution not required

Q. Based on lattice energy and other considerations, which one of the following alkali metal chloride is expected to have the highest melting point ?

(1) RbCl

(2) LiCl

(3) KCl

(4) NaCl

[JEE MAIN-2012, Online]

Sol. (4)

NaCl having highest lattice energy have highest melting point among these.

Q. Which one of the following will react most vigorously with water ?

(1) Li (2) K (3) Rb (4) Na

[JEE MAIN-2012, Online]

Sol. (3)

Down the group reactivity of s-block metals increases.

Q. A metal M on heating in nitrogen gas gives Y. Y on treatment with $\mathrm{H}_{2} \mathrm{O}$ gives a colourless gas which when passed through $\mathrm{CuSO}_{4}$ solution gives a blue colour, Y is :-

(1) $\mathrm{NH}_{3}$

(2) MgO

(3) $\mathrm{Mg}_{3} \mathrm{N}_{2}$

(4) $\mathrm{Mg}\left(\mathrm{NO}_{3}\right)_{2}$

[JEE MAIN-2012, Online]

Sol. (3)

$\mathrm{M}+\mathrm{N}_{2} \rightarrow$ metal nitride (y) so according to the given options answer is (3)

Q. The correct statement for the molecule, $\mathrm{CSI}_{3}$, is :

(1) it contains $\mathrm{Cs}^{3+}$ and I– ions

(2) it contains $\mathrm{Cs}^{+}$, I– and lattice I2 molecule

(3) it is a covalent molecule

(4) it contains $\mathrm{Cs}^{+}$ and ions.


Sol. (4)

$\mathrm{CsI}_{3}$ is ionic compound which have $\mathrm{Cs}^{\oplus}$ and $\mathrm{I}_{3}^{\oplus}$ ion.

Q. Which of the following statements about $\mathrm{Na}_{2} \mathrm{O}_{2}$ is not correct ?

(1) $\mathrm{Na}_{2} \mathrm{O}_{2}$ oxidises $\mathrm{Cr}^{3+}$ to $\mathrm{CrO}_{4}^{2-}$ in acid medium

(2) It is diamagnetic in nature

(3) It is the super oxide of sodium

(4) It is a derivative of $\mathrm{H}_{2} \mathrm{O}_{2}$

[JEE MAIN-2014, Online]

Sol. (3)

$\mathrm{Na}_{2} \mathrm{O}_{2}$ is sodium peroxide not the superoxide.

Q. Amongst LiCl, RbCl, $\mathrm{BeCl}_{2}$ and $\mathrm{MgCl}_{2}$ the compounds with the greatest and the least ionic character, respectively are :

(1) $\mathrm{RbCl}$ and $\mathrm{MgCl}_{2}$

(2) LiCl and RbCl

(3) $\mathrm{MgCl}_{2}$ and $\mathrm{BeCl}_{2}$

(4) $\mathrm{RbCl}$ and $\mathrm{BeCl}_{2}$

[JEE MAIN-2014, Online]

Sol. (4)

Due to smallest cationic size $\mathrm{BeCl}_{2}$ is least ionic while due to biggest ionic size of $\mathrm{Rb}^{\oplus}$, RbCl has greatest ionic character.

Q. The correct order of thermal stability of hydroxides is :


Sol. (3)

For the ionic compound having polyatomic anion, thermal stability increases down the group.

Q. Which of the alkaline earth metal halide given below is essentially covalent in nature :-

(1) $\mathrm{SrCl}_{2}$

(2) $\mathrm{CaCl}_{2}$

(3) $\mathrm{BeCl}_{2}$

(4) $\mathrm{MgCl}_{2}$


Sol. (3)

Fact based.


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  • July 7, 2020 at 10:52 am

    super still want more

  • June 22, 2020 at 1:15 am

    If every year questions were available then it would be more helpful!!!anyways thank you☺☺

  • June 14, 2020 at 1:03 pm

    thanqu so much for these valuable question…it is very helpfull for medical aspirants

  • June 9, 2020 at 7:52 pm

    Bhai 2020 tk ke questions post kr dete please