Tiêu đề 10. THE S-BLOCK ELEMENTS - 01.pdf ✅

1 ADVANCED BATCH S-Block Single Correct Question 1. The yellow colour of chromates changes to orange on acidification due to formation of (1) Cr3+ (2) Cr2O3 (3) Cr2O7 − (4) CrO4 − 2. The compounds A and B according to the reaction given below are (1) CuCN, K2 [Cu(SO4 )] (2) Cu(CN)2, Cul2 (3) Cu2I2, K3 [Cu(CN)4 ] (4) Cul2, K2 [Cu(CN)4 ] 3. The wrong statement regarding transition metals among the following is : (1) 4 s electrons penetrate towards the nucleus more than 3 d electrons (2) atomic radii of transition metals increase rapidly with increase in atomic number because of poor shielding of nuclear attraction by (n − 1) d electrons (3) second and third transition series elements have nearly the same size (4) their densities are higher and densities of the 5 d series elements are higher than those of 4 d series elements. 4. First IE of 5 d series elements are higher than those of 3 d and 4 d series elements. This is due to : (1) bigger size of atoms of 5 d-series elements than 3 d-series elements. (2) greater effective nuclear charge is experienced by valence electrons because of the weak shielding of the nucleus by 4f-electrons in 5 d series. (3) (1) and (2) both. (4) None of these. 5. Ionisation energies of Ni and Pt in kJmol−1 are given below. (⏟IE ) 1 + ( IE ) 2 (⏟IE ) 3 + ( IE ) 4 Ni 2.49 8.80 Pt 2.60 6.70 So, (select the correct statement) (1) nickel (II) compounds tend to be thermodynamically more stable than platinum (II) (2) platinum (IV) compounds tend to be more stable than nickel (IV) (3) (1) & (2) both (4) none is correct More than type Questions 6. Which of the following compounds are coloured due to charge transfer spectra? (1) K2Cr2O7 (2) KMnO4 (3) AgBr (4) FeSO4 7. Which of the following statement is correct when a mixture of CaCl2 and K2Cr2O7 is gently warmed with conc. H2SO4 acid? (1) Deep red vapours are evolved (2) The vapours when passed into NaOH solution gives a yellow solution of Na2CrO4 (3) Chlorine gas is evolved (4) Chromyl chloride is formed 8. Which of the following statements are correct ? (1) Transition elements exhibit higher enthalpies of atomization as they have stronger interatomic interaction. (2) IE2 of 23 V < 24Cr > 25Mn and 28Ni < 29Cu > 30Zn (3) Ni( II) compounds are more stable than Pt(II) where as Pt(IV) compounds are more stable than nickel (IV). (4) The elements which gives the greatest number of oxidation states does not occur in or near the middle of the series. DPP - 01
2 9. Which of the following statement is/are correct? (1) Transition metals and their many compounds act as good catalyst. (2) The enthalpies of atomistation of the transition metals are high. (3) The transition metals generally form interstitial compounds with small atoms like C, B, H etc. (4) All transition metal compounds are not paramagnetic. 10. Incorrect statement is/are (1) In acidic medium MnO4 −disproportionates to MnO2 and MnO4 2− (2) KMnO4 spot can be bleached by H2O2 (3) Alkaline KMnO4 can be used to test unsaturation in (4) Eq. wt. of KMnO4 in acidic medium is M 5 Integer Type Question 11. Total number of 3 d -series transition elements contain either 3 d 1 or 4 s 1 orbital in their ground state electronic configuration. 12. An element of I st transition series X +3 have highest magnetic moment in series and X +2 have non magnetic nature as low spin complex. If Atomic number of X is ' a ' and number of unpaired e −in free state X +2 and X +3 is ' b ' and ' c ' then calculate a + b + 2c. 13. Statement -1 : Ti metal is present in Ziegler Natta catalyst. Statement -2 : Os with +8 oxidation state exists in OsF8 . Statement- 3: +7 oxidation state is more stable for 4 d and 5 d elements compared to 3 d metal. (1) TTT (2) TFT (3) FTT (4) FFT 14. What should be the oxidation state of iron for maximum magnetic moment? Matrix type Questions 15. Match the pairs of complexes/compounds listed in column(I) with the characteristic(s) of the reaction products listed in column(II). Column - I Column - II (A) Cu(I) and Zn(II) complexes (p) Pair of compounds having similar colour and some magnetic moment but equal. (B) KMnO4 and K2Cr2O7 (q) Pair of compounds which are diamagnetic but coloured. (C) Cu2O and Hgl2 (r) Pair of compounds having metals in the highest stable oxidation states. (D) VOCl2 and CuCl2 (s) Pair of compounds which show diamagnetism and are

4 Answer Key 1. (3) 2. (3) 3. (2) 4. (3) 5. (3) 6. (1, 2) 7. (1, 2, 4) 8. (1, 2, 3) 9. (1, 2, 3, 4) 10. (1, 3) 11. (3) 12. (40) 13. (2) 14. (3) 15. (A) − s; (B) − q, r; (C) − q; (D) − p 16. (A) − r; (B) − s; (C) − p; (D) − q 17. (3) 18. (3) 19. (3) 20. (4)