d- and f-Block Elements PYQs Set 15 (PDF)

Set 15 of 15 · Questions 421-443 of 443

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Mere Teacher · Previous Year Questions JEE Main Chemistry · d- and f-Block Elements · Set 15 (Q421-443)
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421. $When a brown compound of Mn (A) is treated with HCl, it gives a gas (B). The gas (B) taken in excess reacts with NH_{3} to give an explosive compound (C). The compounds A, B and C are$ (1) $A = MnO_{2}, B = Cl_{2}, C = NCl_{3}$ (2) $A = MnO, B = Cl_{2}, C = NH_{3} Cl$ (3) $A = Mn_{3} O_{4}, B = Cl_{2}, C = NCl_{3}$ (4) $A = MnO_{3}, B = Cl_{2}, C = NCl_{2}$ 422. $Highest oxidation state of Mn is exhibited in M n_{2} O_{7} . The correct statements about M n_{2} O_{7} are (A) Mn is tetrahedrally surrounded by oxygen atoms (B) Mn is octahedrally surrounded by oxygen atoms (C) Contains Mn-O-Mn bridge (D) Contains Mn-Mn bond. Choose the correct answer from the options given below$ (1) $A and C only$ (2) $A and D only$ (3) $B and D only$ (4) $B and C only$ 423. $Number of electrons transferred in each case when K M n O_{4} acts as an oxidising agent to give M n O_{2}, M n^{2 +}, Mn (O H)_{3} and MnO_{4}^{2-} are respectively :$ (1) $3, 5, 4 and 1$ (2) $4, 3, 1 and 5$ (3) $1, 3, 4 and 5$ (4) $5, 4, 3 and 1$ 424. $When X O_{2} is fused with an alkali metal hydroxide in presence of an oxidizing agent such as K N O_{3}; a dark green product is formed which disproportioates in acidic solution to afford a dark purple solution. X is :$ (1) $Mn$ (2) $Cr$ (3) $V$ (4) $Ti$ 425. $During the qualitative analysis of S O_{3}^{2 -} using dilute H_{2} S O_{4}, S O_{2} gas is evolved which turns K_{2} C r_{2} O_{7} solution (acidified with dilute H_{2} S O_{4}):$ (1) $Black$ (2) $Red$ (3) $Green$ (4) $Blue$ 426. $For the reaction, Cr_{2} O_{7}^{2 -} pH = x CrO_{4}^{2 -} pH = y Cr_{2} O_{7}^{2 -} pH values 'x' and 'y' can be$ (1) $4 and 5$ (2) $4 and 8$ (3) $8 and 4$ (4) $8 and 9$ 427. $Preparation of potassium permanganate from MnO_{2} involves two step process in which the 1st step is a reaction with KOH and KNO_{3} to produce$ (1) $K_{3} MnO_{4}$ (2) $K_{4} (Mn (OH)_{6})$ (3) $KMnO_{4}$ (4) $K_{2} MnO_{4}$ 428. $An ammoniacal metal salt solution gives a brilliant red precipitate on addition of dimethylglyoxime. The metal ion is ;$ (1) $C u^{2 +}$ (2) $C o^{2 +}$ (3) $Fe$ (4) $N i^{2 +}$ 429. $The manganate and permanganate ions are tetrahedral, due to:$ (1) $The π-bonding involves overlap of d-orbitals of oxygen with d-orbitals of manganese.$ (2) $The π-bonding involves overlap of p-orbitals of oxygen with d-orbitals of manganese.$ (3) $There is no π-bonding.$ (4) $The π-bonding involves overlap of p-orbitals of oxygen with p-orbitals of manganese.$ 430. $The set having ions which are coloured and paramagnetic both is -$ (1) $C u^{2 +}, C r^{3 +}, S c^{+}$ (2) $C u^{2 +}, Z n^{2 +}, M n^{4 +}$ (3) $S c^{3 +}, V^{5 +}, T i^{4 +}$ (4) $N i^{2 +}, M n^{7 +}, H g^{2 +}$ 431. $In neutral or alkaline solution, M n O_{4}^{-} oxidises thiosulphate to:$ (1) $S_{2} O_{7}^{2 -}$ (2) $S_{2} O_{8}^{2 -}$ (3) $S O_{3}^{2 -}$ (4) $S O_{4}^{2 -}$ 432. $The ionic charges of manganate and permanganate ion are respectively$ (1) $- 2, - 2$ (2) $- 1, - 2$ (3) $- 2, - 1$ (4) $- 1, - 1$ 433. $The total number of Mn = O bonds in M n_{2} O_{7} is ______$ (1) $4$ (2) $5$ (3) $6$ (4) $3$ 434. $In alkaline medium. MnO_{4}^{-} oxidises I^{-} to$ (1) $IO_{4}^{-}$ (2) $IO^{-}$ (3) $I_{2}$ (4) $IO_{3}^{-}$ 435. $Which of the following pair is not isoelectronic species? (At. no. Sm, 62; Er, 68: Yb, 70: Lu, 71; Eu, 63: Tb, 65; Tm, 69)$ (1) $S m^{2 +} and E u^{3 +}$ (2) $Y b^{2 +} and L u^{3 +}$ (3) $E u^{2 +} and T b^{4 +}$ (4) $T b^{2 +} and T m^{4 +}$ 436. $Which transition metal oxide among the following has electrical conductivity similar to that of copper?$ (1) $MnO$ (2) $FeO$ (3) $Re O_{3}$ (4) $Ti O_{2}$ 437. $The correct statement is$ (1) $the earlier members of lanthanoid series resemble calcium in their chemical properties$ (2) $the extent of actinoid contraction is almost the same as lanthanoid contraction$ (3) $in general, lanthanoids and actinoids do not show variable oxidation states$ (4) $Ce^{4 +} in aqueous solution is not known.$ 438. $Which of the statements is not true?$ (1) $On passing H_{2} S through acidified K_{2} C r_{2} O_{7} solution, a milky colour is observed.$ (2) $N a_{2} C r_{2} O_{7} is preferred over K_{2} C r_{2} O_{7} in volumetric analysis.$ (3) $K_{2} C r_{2} O_{7} solution in acidic medium is orange.$ (4) $K_{2} C r_{2} O_{7} solution becomes yellow on increasing the p H beyond 7.$ 439. $Potassium dichromate acts as a strong oxidizing agent in acidic solution. During this process, the oxidation state changes from (a) + 3 to +l (b) + 6 to + 3$ 440. $The difference in oxidation state of chromium in chromate and dichromate salts is_______$ 441. $The oxidation state of manganese in the product obtained in a reaction of potassium permanganate and hydrogen peroxide in basic medium is______.$ 442. $The spin-only magnetic moment value of the most basic oxide of vanadium among V_{2} O_{3}, V_{2} O_{4} and V_{2} O_{5} is________B.M. (Nearest Integer)$ 443. $The spin-only magnetic moment value of the compound with strongest oxidizing ability among M n F_{4}, M n F_{3} and M n F_{2} is ______B.M. [nearest integer]$