p-Block Elements PYQs Set 5 (PDF)

Set 5 of 15 · Questions 121-150 of 423

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Mere Teacher · Previous Year Questions JEE Main Chemistry · p-Block Elements · Set 5 (Q121-150)
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121. $The ability of a substance to assume two or more crystalline structures is called$ (1) $isomerism$ (2) $polymorphism$ (3) $isomorphism$ (4) $amorphism.$ 122. $Which of the following phosphorus is the most reactive?$ (1) $Scarlet phosphorus$ (2) $White phosphorus$ (3) $Red phosphorus$ (4) $Violet phosphorus$ 123. $Which one of the following statements about the zeolite is false?$ (1) $They are used as cation exchangers.$ (2) $They have open structure which enables them to take up small molecules.$ (3) $Zeolites are aluminosilicates having three-dimensional network.$ (4) $Some of the S i O_{4}^{4 -} units are replaced by A l O_{4}^{5 -} and A l O_{6}^{9 -} ions in zeolites.$ 124. $Which of the following is the increasing order of enthalpy of vaporization ?$ (1) $NH3, PH3, AsH3$ (2) $AsH3, PH3, NH3$ (3) $NH3, AsH3, PH3$ (4) $PH3, AsH3, NH3$ 125. $Identify the element having general electronic configuration n s^{2} n p^{4} from following.$ (1) $Se$ (2) $Br$ (3) $Xe$ (4) $Kr$ 126. $Method used for obtaining highly pure silicon, used as a semiconductor material, is$ (1) $crystallization$ (2) $zone refining$ (3) $oxidation$ (4) $electrochemical.$ 127. $Which of the following sets has strongest tendency to form anions?$ (1) $Ga, Ni, Tl$ (2) $Na, Mg, Al$ (3) $N, O, F$ (4) $V, Cr, Mn.$ 128. $Consider the following elements In, Tl, Al, Pb, Sn and Ge . The most stable oxidation states of elements with highest and lowest first ionisation enthalpies, respectively, are$ (1) $+4 and +1$ (2) $+1 and +4$ (3) $+4 and +3$ (4) $+2 and +3$ 129. $Number of electrons shared in the formation of nitrogen molecule is$ (1) $6$ (2) $10$ (3) $2$ (4) $8$ 130. $The number of pentagons in C_{60} and trigons (triangles) inwhite phosphorous, respectively, are:$ (1) $20 and 3$ (2) $12 and 4$ (3) $12 and 3$ (4) $20 and 4$ 131. $Which of the following has the greatest electron affinity?$ (1) $I$ (2) $Br$ (3) $F$ (4) $Cl$ 132. $Which one of the following orders presents the correct sequence of the increasing basic nature of the given oxides ?$ (1) $A l_{2} O_{3} < MgO < N a_{2} O < K_{2} O$ (2) $MgO < K_{2} O < A l_{2} O_{3} < N a_{2} O$ (3) $N a_{2} O < K_{2} O < MgO < A l_{2} O_{3}$ (4) $K_{2} O < N a_{2} O < A l_{2} O_{3} < MgO$ 133. $It is because of inability of n s^{2} electrons of the valence shell to participate in bonding that$ (1) $S n^{2 +} is oxidising while P b^{4 +} is reducing$ (2) $S n^{2 +} and P b^{2 +} are both oxidising and reducing$ (3) $S n^{4 +} is reducing while P b^{4 +} is oxidising$ (4) $S n^{2 +} is reducing while P b^{4 +} is oxidising.$ 134. $Dinitrogen is a robust compound, but reacts at high altitude to form oxides. The oxide of nitrogen that can damage plant leaves and retard photosynthesis is .$ (1) $NO$ (2) $N O_{3}^{-}$ (3) $N O_{2}$ (4) $N O_{2}^{-}$ 135. $Which from following molecules exhibits highest acidic nature?$ (1) $H_{2} O$ (2) $H_{2} S$ (3) $H_{2} Se$ (4) $H_{2} Te$ 136. $HF has highest boiling point among hydrogen halides, because it has:$ (1) $strongest van der Waals' interactions$ (2) $lowest ionic character$ (3) $strongest hydrogen bonding$ (4) $lowest dissociation enthalpy$ 137. $Which of the following statements is not true for halogens?$ (1) $All form monobasic oxyacids.$ (2) $All are oxidizing agents.$ (3) $All but fluorine show positive oxidation states.$ (4) $Chlorine has the highest electron‐gain enthalpy$ 138. $Given below are two statements : Statement I :Colourless cupric metaborate is reduced to cuprous metaborate in a luminous flame. Statement II : Cuprous metaborate is obtained by heating boric anhydride and copper sulphate in a non-luminous flame. choose the most appropriate answer from the optionsgiven below.$ (1) $Statement I is false but statement II is true.$ (2) $Statement is true but Statement II is false.$ (3) $Both Statement I and Statement II are true.$ (4) $Both Statement I and Statement II are false.$ 139. $In which one of the following molecules strongest back donation of an electron pair from halide to boron is expected?$ (1) $B C l_{3}$ (2) $B F_{3}$ (3) $B B r_{3}$ (4) $B I_{3}$ 140. $Boron compounds behave as Lewis acids, because of them$ (1) $ionisation property$ (2) $electron deficient nature$ (3) $acidic nature$ (4) $covalent nature.$ 141. $The ion that has s p^{3} d^{2} hydridization for the central atom, is:$ (1) $I C l_{4}^{-}$ (2) $(ICl_{2})^{-}$ (3) $I F_{6}^{-}$ (4) $(BrF_{2})^{-}$ 142. $Given below are two statements: Statement I: The boiling points of the following hydrides of group 16 elements increases in the order: H_{2} O < H_{2} S < H_{2} Se < H_{2} Te . Statement II: The boiling points of these hydrides increase with increase in molar mass. choose the most appropriate answer from the options given below:$ (1) $Statements I is incorrect but Statements II is correct.$ (2) $Both Statements I and Statements II are correct$ (3) $Both Statements I and Statements II are incorrect$ (4) $Statements I is correct but Statements II is incorrect$ 143. $The large difference between the melting and boiling points of oxygen and sulphur may be explained on the basis of$ (1) $Atomicity$ (2) $Electron gain enthalpy$ (3) $Electronegativity$ (4) $Atomic size$ 144. $White phosphorus on reaction with concentrated NaOH solution in an inert atmosphere of C O_{2} gives phosphine and compound (X) . (X) on acidification with HCl gives compound (Y) . The basicity of compound (Y) is :$ (1) $1$ (2) $2$ (3) $3$ (4) $4$ 145. $The nature of oxide (TeO_{2}) and hydride (TeH_{2}) formed by Te, respectively are:$ (1) $Reducing and basic$ (2) $Reducing and acidic$ (3) $Oxidizing and acidic$ (4) $Oxidizing and basic$ 146. $Which among the following is the most reactive ?$ (1) $Cl2$ (2) $Br2$ (3) $Ι2$ (4) $ΙCl$ 147. $The correct order of thermal stability of hydroxides is :$ (1) $Ba (O H)_{2} < Ca (O H)_{2} < Sr (O H)_{2} < Mg (O H)_{2}$ (2) $Ba (O H)_{2} < Sr (O H)_{2} < Ca (O H)_{2} < Mg (O H)_{2}$ (3) $Mg (O H)_{2} < Ca (O H)_{2} < Sr (O H)_{2} < Ba (O H)_{2}$ (4) $Mg (O H)_{2} < Sr (O H)_{2} < Ca (O H)_{2} < Ba (O H)_{2}$ 148. $Bleaching powder reacts with a few drops of conc. HC1 to give$ (1) $chlorine$ (2) $hypochlorous acid$ (3) $calcium oxide$ (4) $oxygen.$ 149. $Sum of oxidation states of bromine in bromine acid and perbromic acid is________.$ 150. $The ratio of number of water molecules in Mohr's salt and potash alum is ____x 1 0^{- 1} . (Integer answer)$