s-Block Elements PYQs Set 3 (PDF)

Set 3 of 20 · Questions 61-90 of 584

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Mere Teacher · Previous Year Questions JEE Main Chemistry · s-Block Elements · Set 3 (Q61-90)
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61. $A and B are formed when borax is dissolved in water. C and B are formed when borax is reacted with aqueous HCl solution. What are A and C respectively?$ (1) $NaCl, NaOH$ (2) $NaOH, NaCl$ (3) $NaBO_{2}, NaCl$ (4) $NaOH, NaBO_{2}$ 62. $The element having greatest difference between its first and second ionization energies is:$ (1) $Ca$ (2) $Sc$ (3) $Ba$ (4) $K$ 63. $Which one of the following is not a colourless compound?$ (1) $NO$ (2) $N_{2} O_{4}$ (3) $N_{2} O$ (4) $NO_{2}$ 64. $BF_{3} reacts with NaH at 450 K to form NaF and X . When X reacts with LiH in diethyl ether, Y is formed. What is Y ?$ (1) $LiBO_{2}$ (2) $Li_{2} B_{4} O_{7}$ (3) $LiBH_{4}$ (4) $B_{2} H_{6} \cdot LiH$ 65. $From the following statements regarding H_{2} O_{2}, choose the incorrect statement :$ (1) $It can act only as an oxidizing agent$ (2) $It decomposed on exposure to light$ (3) $It has to be stored in plastic or wax lined glass bottles in dark$ (4) $It has to be kept away from dust$ 66. $The oxide that gives H_{2} O_{2} most readily on treatment with H_{2} O is :$ (1) $P b O_{2}$ (2) $N a_{2} O_{2}$ (3) $S n O_{2}$ (4) $B a O_{2} \cdot 8 H_{2} O$ 67. $The correct order of melting points of Al, Ga, In is$ (1) $Ga < In < Al$ (2) $In < Ga < Al$ (3) $Al < Ga < In$ (4) $Ga < Al < In$ 68. $In the flame test of a mixture of salts, a green flame with blue centre was observed. Which one of the following cations may be present?$ (1) $C u^{2 +}$ (2) $S r^{2 +}$ (3) $B a^{2 +}$ (4) $C a^{2 +}$ 69. $Metal ' M' in the following reaction is 2 MNO_{3} \to M_{2} O + 2 NO_{2} + \frac{1}{2} O_{2}$ (1) $Cs$ (2) $K$ (3) $Na$ (4) $Li$ 70. $Highly pure dilute solution of sodium in liquid ammonia :$ (1) $shows blue colour.$ (2) $exhibits electrical conductivity.$ (3) $produces sodium amide.$ (4) $produces hydrogen gas$ 71. $Assertion (A) : (B (OH_{2})_{6})^{3 +} and B(OH)4-form octahedral and tetrahedral structures.Reason (R) : Bcing electron deficient, boron readily reacts with Lewis bases like H_{2} O, OH^{-} The correct option among the following is$ (1) $(A) is true, (R) is true and (R) is the correct explanation for (A)$ (2) $(A) is true, (R) is true but (R) is not the correct explanation for (A)$ (3) $(A) is true but (R) is false$ (4) $(A) is false but (R) is true$ 72. $(N H_{4})_{2} C r_{2} O_{7} on heating gives a gas which is also given by$ (1) $heating N H_{4} N O_{2}$ (2) $heating N H_{4} N O_{3}$ (3) $treating M g_{3} N_{2} with H_{2} O$ (4) $treating Na(compound) with H_{2} O_{2}$ 73. $A metallic oxide reacts with water to form its hydroxide, hydrogen peroxide and also liberates oxygen. The metallic oxide could be$ (1) $CaO$ (2) $KO_{2}$ (3) $Li_{2} O$ (4) $Na_{2} O_{2}$ 74. $Concentrated nitric acid, upon long standing, turns yellow-brown due to the formation of :$ (1) $NO$ (2) $N O_{2}$ (3) $N_{2} O$ (4) $N_{2} O_{4}$ 75. $Hydrogen peroxide in its reaction with K I O_{4} and N H_{2} OH respectively, is acting as a$ (1) $reducing agent, oxidising agent$ (2) $reducing agent, reducing agent$ (3) $oxidising agent, oxidising agent$ (4) $oxidising agent, reducing agent$ 76. $The functional groups that are responsible for the ion-exchange property of cation and anion exchange resins, respectively, are:$ (1) $- SO_{3} H and - NH_{2}$ (2) $- SO_{3} H and -COOH$ (3) $- NH_{2} and -COOH$ (4) $- NH_{2} and - SO_{3} H$ 77. $Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R Assertion A :- The alkali metals and their salts impart characteristic colour to reducing flame. Reason R :- Alkali metals can be detected using flame tests. choose the most appropriate answer form the options given below$ (1) $Both A and R are correct but R is NOT the correct explanation of A.$ (2) $A is correct but R is not correct,$ (3) $A is not correct but R is correct$ (4) $Both A and R are correct and R is the correct explanation of A.$ 78. $Which one of the following statements is not correct?$ (1) $Molecular formula of calgon is NaAlSiO_{4}$ (2) $Beryllium halides are soluble in organic solvents$ (3) $Among alkali metals, the reducing property of sodium is least in aqueous solution$ (4) $White metal is an alloy of Lithium$ 79. $Match List I with List IL LIST I A. Chlorophyll B. Soda ash C. Dentistry, Ornamental work D. Used in white washing LIST II I. N a_{2} C O_{3} II. C a S O_{4} III. M g^{2 +} IV. Ca (O H)_{2} Choose the correct answer from the options given below:$ (1) $A-III,B-I,C-II,D-IV$ (2) $A-II,B-I,C-III,D-IV$ (3) $A-III,B-IV,C-I,D-II$ (4) $A- II, B - III, C - IV, D - I$ 80. $Conc. HNO_{3} turns brown on standing due to formation of\dots\dots\dots\dots$ (1) $NO$ (2) $NO_{2}$ (3) $N_{2} O$ (4) $N_{2} O_{4}$ 81. $The correct sequence of thermal stability of the following carbonates:$ (1) $BaC O_{3} < CaC O_{3} < SrC O_{3} < MgC O_{3}$ (2) $MgC O_{3} < CaC O_{3} < SrC O_{3} < BaC O_{3}$ (3) $MgC O_{3} < SrC O_{3} < CaC O_{3} < BaC O_{3}$ (4) $BaC O_{3} < SrC O_{3} < CaC O_{3} < MgC O_{3}$ 82. $Assertion (A) : Noble gases have very low boiling points. Reason (R) : All noble gases have general electronic configuration of n s^{2} n p^{6} (except He).$ (1) $Both (A) and (R) are true and (R) is the correct explanation of (A)$ (2) $(A) is false but (R) is true$ (3) $(A) is true but (R) is false$ (4) $Both (A) and (R) are true and (R) is the not the correct explanation of (A)$ 83. $Solubility of the alkaline earth metal sulphates in water decreases in the sequence$ (1) $Sr > C a > M g > B a$ (2) $Ba > M g > S r > C a$ (3) $Mg > C a > S r > B a$ (4) $Ca > S r > B a > M g$ 84. $In which one of the following pairs, both oxides are acidic?$ (1) $CO, CO_{2}$ (2) $SnO, PbO_{2}$ (3) $GeO, SiO_{2}$ (4) $SnO, PbO$ 85. $Amphoteric hydroxide from the following is$ (1) $Al (OH)_{3}$ (2) $In (OH)_{3}$ (3) $B (OH)_{3}$ (4) $Tl (OH)_{3}$ 86. $When carbon monoxide is passed over solid caustic soda heated to 200^{\circ} C, it forms$ (1) $HCOONa$ (2) $Na_{2} CO_{3}$ (3) $2 CH_{3} COONa$ (4) $NaHCO_{3}$ 87. $All the following substances react with water. The pair that gives the same gaseous product is$ (1) $K and K O_{2}$ (2) $Na and N a_{2} O_{2}$ (3) $Ca and C a H_{2}$ (4) $Ba and B a O_{2} .$ 88. $Which among the following compound shows the highest lattice energy?$ (1) $LiF$ (2) $CsF$ (3) $NaF$ (4) $KF$ 89. $Identify the correct statements from the following : I. Tendency to form halide hydrates gradually increases from Be to Ba down the group. II. Tendency to form stable super oxides increases from Li to Cs down the group. III. Low solubility of LiF is due to its high lattice energy. IV. Solubility of carbonates of group-2 elements increases down the group.$ (1) $I, II$ (2) $III, IV$ (3) $II, III$ (4) $I, III$ 90. $Which element among the following does not form diatomic molecules?$ (1) $Argon$ (2) $Oxygen$ (3) $Nitrogen$ (4) $Bromine$