s-Block Elements PYQs Set 6 (PDF)

Set 6 of 20 · Questions 151-180 of 584

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Mere Teacher · Previous Year Questions JEE Main Chemistry · s-Block Elements · Set 6 (Q151-180)
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151. $On combustion of Li, Na and K in excess of air, the major oxides formed, respectively, are$ (1) $Li2O,Na2O2and K_{2} O_{2}$ (2) $Li_{2} O_{2}, Na_{2} O_{2} and K_{2} O_{2}$ (3) $Li2O,Na2O2and KO_{2}$ (4) $Li_{2} O, Na_{2} O and K_{2} O_{2}$ 152. $Assertion (A) : Alkali metals are soft and have low melting and boiling points. Reason (R) : This is because interatomic bonds are weak.$ (1) $Both (A) and (R) are not true$ (2) $(A) is true but (R) is not the correct explanation of (A)$ (3) $(A) is true but (R) is false$ (4) $Both (A) and (R) are true and (R) is the correct explanation of (A)$ 153. $Which of the following is not a disadvantage of using hard water?$ (1) $In production of steam in boilers$ (2) $Formation of scales in cooking utensils$ (3) $In cooking, bathing and washing$ (4) $In ion exchangers$ 154. $A metal (A) on heating in nitrogen gas gives compound B . B on treatment with H_{2} O gives a colorless gas which when passed through CuSO_{4} solution gives a dark blue-violet coloured solution. A and B respectively, are:$ (1) $Mg, M g_{3} N_{2}$ (2) $Na N a_{3} N$ (3) $MgMg (N O_{3})_{2}$ (4) $Na NaNO_{3}$ 155. $Statement I: Sulphur vapour is paramagnetic. Statement II: Reaction of dil. HCl with finely divided iron forms FeCl_{3} and H_{2} gas.$ (1) $Statement I is correct, but statement II is wrong.$ (2) $Both the statements are correct.$ (3) $Statement I is wrong, but statement II is correct.$ (4) $Both the statements are wrong.$ 156. $The main products P and Q of the following unbalanced disproportionation reaction are SeCl_{2} \to P + Q P Q$ (1) $SeCl_{2} SeCl_{3}$ (2) $SeCl_{4} SeCl_{2}$ (3) $SeCl_{4} Se$ (4) $SeCl_{4} Se_{2}$ 157. $The hybridizations of carbon in graphite, diamond and C_{60} are respectively$ (1) $sp^{2}, sp^{3}, sp$ (2) $sp^{2}, sp^{3}, sp^{2}$ (3) $sp, sp^{2}, sp^{3}$ (4) $sp, sp^{3}, sp$ 158. $Among the hydrides of group 16 elements, the hydride X has lowest boiling point and the hydride Y has highest boiling point. X and Y respectively are$ (1) $H_{2} Te, H_{2} Se$ (2) $H_{2} O, H_{2} Te$ (3) $H_{2} S, H_{2} Te$ (4) $H_{2} S, H_{2} O$ 159. $The correct decreasing order of the following ' Xe' compounds to act as both fluorinating and oxidizing agent is (i) XeF_{6} (ii) XeF_{4} (iii) XeF_{2}$ (1) $XeF_{2} > XeF_{4} > XeF_{6}$ (2) $XeF_{6} > XeF_{4} > XeF_{2}$ (3) $XeF_{4} > XeF_{6} > XeF_{2}$ (4) $XeF4>XeF2>XeF6$ 160. $Aqueous solution of N a_{2} S_{2} O_{3} on reaction with C l_{2} gives :$ (1) $N a_{2} S_{4} O_{6}$ (2) $N a H S O_{4}$ (3) $NaCl$ (4) $NaOH$ 161. $Which among the following element has only one electron in valence shell?$ (1) $Ba$ (2) $Rb$ (3) $Ca$ (4) $Ra$ 162. $Among the alkali metals cesium is the most reactive because$ (1) $its incomplete shell is nearest to the nucleus$ (2) $it has a single electron in the valence shell$ (3) $it is the heaviest alkali metal$ (4) $the outermost electron is more loosely bound than the outermost electron of the other alkali metals.$ 163. $The correct order of melting points of the following salts is LiCl LiF LiI I II III$ (1) $I > II > III$ (2) $II > I > III$ (3) $III > II > I$ (4) $II > III > I$ 164. $Statement-1 : Alkali metals dissolve in liquid ammonia to give blue solutions. Statement-2 : Alkali metals in liquid ammonia give solvated species of the type [M(N H_{3})_{n}]^{+} (M = alkali metals).$ (1) $Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1.$ (2) $Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1.$ (3) $Statement-1 is True, Statement-2 is False.$ (4) $Statement-1 is False, Statement-2 is True.$ 165. $B e C l_{2} reacts with L i A l H_{4} to give$ (1) $Be + Li[A l C l_{4}] + H_{2}$ (2) $Be + A 1 H_{3} + LiCl + HC1$ (3) $B e H_{2} + LiCl + A 1 C 1_{3}$ (4) $B e H_{2} + Li[A l C l_{4}]$ 166. $The substance not likely to contain C a C O_{3} is :$ (1) $calcined gypsum$ (2) $sea shells$ (3) $dolomite$ (4) $a marble statue$ 167. $The property of the alkaline earth metals that increases with their atomic number is$ (1) $ionisation enthalpy$ (2) $electronegativity$ (3) $solubility of their hydroxides in water$ (4) $solubility of their sulphates in water.$ 168. $Which of the following statement is false?$ (1) $Strontium decomposes water readily than beryllium.$ (2) $Barium carbonate melts at a higher temperature than calcium carbonate.$ (3) $Barium hydroxide is more soluble in water than magnesium hydroxide.$ (4) $Beryllium hydroxide is more basic than barium hydroxide.$ 169. $For ozone molecule consider the following(A) It is a linear molecule with bond angle 180^{\circ} (B) It is an angular molecule with bond angle 117^{\circ} (C) The bond lengths of both O - O bonds are same(D) With respect to oxygen it is thermodynamically more stableThe correct options are$ (1) $(B), (C) only$ (2) $(A), (B) only$ (3) $(B), (D) only$ (4) $(A), (D) only$ 170. $Which of the following is employed in flash tubes in photography?$ (1) $Ar$ (2) $Ne$ (3) $Kr$ (4) $none of the above$ 171. $The element that does not show catenation is$ (1) $C$ (2) $Ge$ (3) $Sn$ (4) $Pb$ 172. $A Lewis acid ' X' reacts with LiAlH_{4} in ether medium to give a highly toxic gas. This gas when heated with NH_{3} gives a compound commonly known as inorganic benzene. The gas is$ (1) $B_{2} H_{6}$ (2) $B_{3} N_{3} H_{6}$ (3) $BF_{3}$ (4) $B_{2} O_{3}$ 173. $X e F_{6} on partial hydrolysis with water produces a compound 'X'. The same compound 'X' is formed when X e F_{6} reacts with silica. The compound 'X' is$ (1) $X e O_{3}$ (2) $X e F_{4}$ (3) $X e F_{2}$ (4) $X e O F_{4}$ 174. $In case of nitrogen, NCl3 is possible but no NCl5 while in case of phosphorus, PCl3 as well as PCl5 are possible. It is due to :$ (1) $availability of vacant d-orbital in P but not in N.$ (2) $lower electronegativity of P then N.$ (3) $lower tendency of H bond formation in P than N.$ (4) $occurrence of P in solid while N in gaseous state at room temperature.$ 175. $Which of the following reactions represents "slaking of lime"?$ (1) $CaCO_{3} ⇌ CaO + CO_{2}$ (2) $CaO + CO_{2} ⟶ CaCO_{3}$ (3) $CaO + H_{2} O ⟶ Ca (OH)_{2}$ (4) $CaO + SiO_{2} ⟶ CaSiO_{3}$ 176. $What is the most abundant element on earth?$ (1) $Hydrogen$ (2) $Nitrogen$ (3) $Oxygen$ (4) $Silicon$ 177. $The aqueous solution of following salt will have the lowest pH$ (1) $NaClO$ (2) $NaClO_{4}$ (3) $NaClO_{3}$ (4) $NaClO_{2}$ 178. $Among the following oxides, which one is weakly basic and yet a powerful oxidant?$ (1) $CO_{2}$ (2) $SnO_{2}$ (3) $SiO_{2}$ (4) $PbO_{2}$ 179. $Brown ring test is used to detect the presence of$ (1) $NO_{3}^{-}$ (2) $Cl^{-}$ (3) $1^{-}$ (4) $Br^{-}$ 180. $The correct order of " Δ_{f} H^{\circ} " values of Diamond (I), Graphite (II) and Fullerene (III) is$ (1) $I > II > III$ (2) $II > I > III$ (3) $III > I > II$ (4) $III > II > I$