s-block - JEE Main Previous Year Questions with Solutions

JEE Main Previous Year Papers Questions of Chemistry With Solutions are available at eSaral. Simulator Previous Years AIEEE/JEE Mains Questions [esquestion] 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) $\mathrm{Li}_{2} \mathrm{O}+\mathrm{NO}+\mathrm{O}_{2}$ #tag# [AIEEE-2011] #sol# (2) Fact based. [/esquestion] [esquestion] 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 #tag# #sol# (3) $\mathrm{O}^{-2}+\mathrm{H}^{\ominus} \rightarrow \mathrm{O}-\mathrm{H}\left\{\mathrm{O}^{-2} \rightarrow \mathrm{H}^{\ominus}\right\}$ [/esquestion] [esquestion] 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 $_{3}$ #tag# [AIEEE-2012] #sol# (4) [/esquestion] [esquestion] 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) $\mathrm{NaHCO}_{3}$ #tag# [JEE MAIN-2012, Online] #sol# (4) Solution not required [/esquestion] [esquestion] 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 #tag# [JEE MAIN-2012, Online] #sol# (4) NaCl having highest lattice energy have highest melting point among these. [/esquestion] [esquestion] Which one of the following will react most vigorously with water ? (1) Li (2) K (3) Rb (4) Na #tag# [JEE MAIN-2012, Online] #sol# (3) Down the group reactivity of s-block metals increases. [/esquestion] [esquestion] 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) $\mathrm{Mg}\left(\mathrm{NO}_{3}\right)_{2}$ #tag# [JEE MAIN-2012, Online] #sol# (3) $\mathrm{M}+\mathrm{N}_{2} \rightarrow$ metal nitride (y) so according to the given options answer is (3) [/esquestion] [esquestion] 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. #tag# [JEE(Main)-2014] #sol# (4) $\mathrm{CsI}_{3}$ is ionic compound which have $\mathrm{Cs}^{\oplus}$ and $\mathrm{I}_{3}^{\oplus}$ ion. [/esquestion] [esquestion] 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 $\mathrm{H}_{2} \mathrm{O}_{2}$ #tag# [JEE MAIN-2014, Online] #sol# (3) $\mathrm{Na}_{2} \mathrm{O}_{2}$ is sodium peroxide not the superoxide. [/esquestion] [esquestion] 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 $\mathrm{BeCl}_{2}$ #tag# [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. [/esquestion] [esquestion] The correct order of thermal stability of hydroxides is : #tag# [JEE(Main)Online-2015] #sol# (3) For the ionic compound having polyatomic anion, thermal stability increases down the group. [/esquestion] [esquestion] 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) $\mathrm{MgCl}_{2}$ #tag# [JEE(Main)Online-2015] #sol# (3) Fact based. [/esquestion]