s-Block Elements PYQs Set 14 (PDF)

Set 14 of 20 · Questions 391-420 of 584

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Mere Teacher · Previous Year Questions JEE Main Chemistry · s-Block Elements · Set 14 (Q391-420)
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391. $The number of hydrogen atom (s) attached to phosphorus atom in hypophosphorus acid is$ (1) $zero$ (2) $two$ (3) $one$ (4) $three$ 392. $Ionic mobility of which of the following alkali metal ions is lowest when aqueous solution of their salts are put under an electric field?$ (1) $K$ (2) $Rb$ (3) $Li$ (4) $Na$ 393. $Which one among the following statements is correct about a solution of borax in water?$ (1) $It is acidic because it contains H_{3} BO_{3} and NaOH$ (2) $It dissociates into NaBO_{2} and B_{2} O_{3}$ (3) $It is neutral because it contains NaOH and H_{3} BO_{3}$ (4) $It is alkaline because it contains NaOH and H_{3} BO_{3}$ 394. $The compound(s) which generate(s) N_{2} gas upon thermal decomposition below 300ºC is (are)$ (1) $N H_{4} N O_{3}$ (2) $(N H_{4})_{2} C r_{2} O_{7}$ (3) $Ba (N_{3})_{2}$ (4) $M g_{3} N_{2}$ 395. $The products formed during thermal decomposition of ammonium dichromate are$ (1) $O_{2}, H_{2} O, Cr (OH)_{3}$ (2) $NO_{2}, H_{2} O, Cr_{2} O_{3}$ (3) $N_{2}, Cr_{2} O_{3}, H_{2} O$ (4) $N_{2} O, Cr (OH)_{3}$ 396. $Identify the correct statements from the following :I. is an amphoteric oxide.II. The dimer of aluminium chloride has three bridge bonds.III. Boron is very hard refractory solid of high melting temperature.$ (1) $I, II only$ (2) $I, III only$ (3) $II, III only$ (4) $I, II, III$ 397. $White phosphorus is heated with concentrated NaOH in CO_{2} atmosphere to form a gas A and compound B . When A is bubbled into aqueous CuSO_{4} solution copper phosphide and C are formed, B and C are respectively$ (1) $PH_{3}, H_{2} SO_{4}$ (2) $NaH_{2} PO_{2}, H_{2} SO_{4}$ (3) $NaHPO_{2}, CuS$ (4) $NaH_{2} PO_{2}, Cu_{2} S$ 398. $Xe (g) + F_{2} (g) \frac{573 K}{60 - 70 bar} X (s) (1 : 20) X + H_{2} O \to Y + HF X + 3 H_{2} O \to Z + HF The correct statements regarding Y and Z are (I) Y has square pyramidal geometry (II) Y has linear geometry (III) Z has 3 σ, 3 π bonds and 1 lone pair of electrons on the central atom (IV) Z has tetrahedral geometry$ (1) $I & III only$ (2) $II & III only$ (3) $III & IV only$ (4) $I & IV only$ 399. $S + Conc. H_{2} SO_{4} ⟶ X + Y Here X is a gas and Y is a liquid and both are triatomic molecules. The number of electron lone pairs present on the central atoms of X and Y are respectively.$ (1) $2,1$ (2) $1,0$ (3) $1,2$ (4) $2,2$ 400. $Assertion (A): SF6 is highly stable. Reason (R): SF6 is a gas.The correct option among the following is$ (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) $(A) is false but (R) is true$ 401. $Statement I : Among the oxides of nitrogen, NO and NO_{2} are paramagnetic. Statement II : NO is paramagnetic in the gaseous state and diamagnetic in liquid state. The correct answer is$ (1) $(I) is correct, (II) is not correct$ (2) $Both (I) and (II) are not correct$ (3) $(I) is not correct, (II) is correct$ (4) $Both (I) and (II) are correct$ 402. $Calcium on heating in N_{2} yields an ionic compound A, which reacts with water to give Ca (OH)_{2} and a gas B . Identify A and B$ (1) $CaN_{2}, NO$ (2) $Ca_{3} N_{2}, NH_{3}$ (3) $CaN_{2}, NH_{3}$ (4) $Ca_{3} N_{2}, NO$ 403. $The oxidation state (n) and coordination number (CN) of Al and number of valence electrons around Al (N) in Al_{2} Cl_{6} are respectively$ (1) $3, 3, 6$ (2) $3, 4, 8$ (3) $4, 4, 8$ (4) $3, 4, 6$ 404. $Magnesium reacts with an element (X) to form an ionic compound. If the ground state electronic configuration of (X) is 1 s^{2} 2 s^{2} 2 p^{3}, the simplest formula for this compound is$ (1) $M g_{2} X_{3}$ (2) $M g X_{2}$ (3) $M g_{2} X$ (4) $M g_{3} X_{2}$ 405. $Which of the compounds among N_{2} O, NO, N_{2} O_{3}, NO_{2}, N_{2} O_{4}, N_{2} O_{5} are diamagnetic?$ (1) $NO, NO_{2}, N_{2} O_{3}$ (2) $N_{2} O, N_{2} O_{3}, N_{2} O_{4}, N_{2} O_{5}$ (3) $NO, NO_{2}$ (4) $N_{2} O_{4}, N_{2} O_{5}$ 406. $Which of the following oxoacids of sulphur has -O-O- linkage ?$ (1) $H_{2} S_{2} O_{3}$ (2) $H_{2} S_{2} O_{5}$ (3) $H_{2} S_{2} O_{6}$ (4) $H_{2} S_{2} O_{8}$ 407. $Lithium nitrate and sodium nitrate, when heated separately, respectively, give :$ (1) $L i N O_{2} and N a N O_{2}$ (2) $L i_{2} O and N a_{2} O$ (3) $L i_{2} O and N a N O_{2}$ (4) $L i N O_{2} and N a_{2} O$ 408. $Commercial name of peroxydisulphuric acid is$ (1) $Marshall's acid$ (2) $Caro's acid$ (3) $oleum$ (4) $fuming sulphuric acid$ 409. $The strong reducing property of hypophosphorous acid is due to$ (1) $two P - H bonds$ (2) $presence of phosphorus in its highest oxidation state$ (3) $its concentration$ (4) $the positive valency of phosphorus.$ 410. $The correct order of the mobility of the alkali metal ions in aqueous solution is$ (1) $R b^{+} > K^{+} > N a^{+} > L i^{+}$ (2) $L i^{+} > N a^{+} > K^{+} > R b^{+}$ (3) $N a^{+} > K^{+} > R b^{+} > L i^{+}$ (4) $K^{+} > R b^{+} > N a^{+} > L i^{+}$ 411. $Unknown inorganic compound ' A' is used for water softening ' A' reacts with Na_{2} CO_{3} to generate an alkaline compound 'B' whose pH = 14 . 'A' on reaction with CO_{2} gives cloudy ppt. 'B' + CaO reacts with unknown organic compound ' C' to give C_{6} H_{6} . A, B and C, respectively, are$ (1) $Ca (OH)_{2}, Na_{2} CO_{3}, C_{6} H_{5} COOH$ (2) $Ca (OH)_{2}, NaOH, C_{6} H_{5} CH_{2} COOH$ (3) $Ca (OH)_{2}, NaOH, C_{6} H_{5} COOH$ (4) $Ca, NaOH, C_{6} H_{5} COOH$ 412. $In the extraction of copper from copper glance, blister copper is formed by the evolution of gas X . The shape of molecule of X is$ (1) $Angular$ (2) $Planar trigonal$ (3) $Tetrahedral$ (4) $Pyramidal$ 413. $The oxidation states of sulphur atoms and number of S-OH bonds in Peroxydisulfuric acid are respectively.$ (1) $(+ 6, + 5), 2$ (2) $(+ 6, + 6), 4$ (3) $(+ 6, + 6), 2$ (4) $(+ 5, + 5), 4$ 414. $When SbF_{5} reacts with XeF_{4} to form an adduct, the shapes of cation and anion in the adduct respectively are$ (1) $square planar, trigonal bipyramidal$ (2) $T-shaped, octahedral$ (3) $square pyramidal, octahedral$ (4) $plane triangular, trigonal bipyramidal$ 415. $The compound A on heating gives a colourless gas and a residue that is dissolved in water to obtain B . Excess of C O_{2} is bubbled through aqueous solution of B, C is formed which is recovered in the solid form. Solid C on gentle heating gives back A . The compound is$ (1) $C a C O_{3}$ (2) $N a_{2} C O_{3}$ (3) $K_{2} C O_{3}$ (4) $C a S O_{4} \cdot 2 H_{2} O$ 416. $In solid state, PC l_{5} is a/an$ (1) $octahedral structure$ (2) $ionic solid with PC l_{6}^{+} and PC l_{4}^{-}$ (3) $ionic solid with PC l_{4}^{+} and PC l_{6}^{-}$ (4) $covalent solid present in the form of P_{2} C l_{10} .$ 417. $AlCl_{3} in water at pH < 7 forms$ (1) $tetrahedral Al (OH)_{4}^{-} ions$ (2) $octahedral Al (OH)_{6}^{3 -} ions$ (3) $square planar Al (OH)_{4}^{-} ions$ (4) $octahedral [Al (O H_{2})_{6}]^{3 +} ions$ 418. $Predict the feasibility of the given reactions in aqueous solution (i) Be (OH)_{2} + 2O H^{-} \to [Be (OH)_{4}]^{2 -} (ii) Be (OH)_{2} + 2 H^{+} + 2 H_{2} O \to [Be (H_{2} O)_{4}]^{2 +}$ (1) $Only (i) is feasible$ (2) $Only (ii) is feasible$ (3) $(i) and (ii) are feasible$ (4) $(i) and (ii) are not feasible$ 419. $The correct order of hydration enthalpies is (A) K^{+} (B) R b^{+} (C) M g^{2 +} (D) C s^{+} (E) C a^{2 +} Choose the correct answer from the options given below:$ (1) $C>A>E>B>D$ (2) $E>C>A>B>D$ (3) $C>E>A>D>B$ (4) $C>E>A>B>D$ 420. $The number of alkali metal(s), from Li, K, Cs, Rb having ionization enthalpy greater than 400 kJ m o l^{- 1} and forming stable super oxide is_____,$