Tiêu đề DPP-4 SOLUTION.pdf ✅

CLASS : XIth SUBJECT : CHEMISTRY DATE : DPP No. : 4 1 (b) Ni combines with CO to form volatile Ni(CO)4 which decomposes to give pure Ni metal and CO on heating. Ni(CO)4 Heat Ni + 4CO↑ Volatile metal 2 (c) In Bessemer’s converter impurities of C, Mn, Si, P in pig iron are oxidized to produce steel. 3 (b) [Ag(CN)2] ― 4 (d) Due to lanthanide contraction there occurs net decrease in size. Only one 0.85 Å is smaller one. 5 (a) When oxyhaemoglobin changes to deoxyhaemoglobin, Fe2+ ion changes from diamagnetic to paramagnetic. 6 (c) Zn blende is ZnS. 7 (d) Transitional metal ion having unpaired electrons are coloured while those which have no unpaired electron are colourless. TiF2― 6 Ti4+ :[Ar]3d 0 ;0 unpaired electrons; colourless Cu2Cl2 Cu+ :[Ar]3d 10;0 unpaired electrons; colourless CoF3― 6 , CO3+ :[Ar]3d 6 ;4 unpaired electrons; coloured NiCl2― 4 Ni2+ :[Ar]3d 8 ;2 unpaired electrons; coloured Topic :- THE D-AND F-BLOCK ELEMENTS Solutions
8 (d) Ti :3d 2 4s 2 ; V:3d 3 4s 2 ; Cr:3d 5 4s 1 ; Mn:3d 5 4s 2 ; Ti 2+:3d 2 ; V 3+:3d 2 ; Cr 4+:3d 2 ; Mn 5+:3d 2 9 (d) Hg2Cl2 + 2NH3 ⟶HgNH2Cl + Hg + NH4Cl white black 10 (b) Molybdenum steel is resistant to acid. 11 (b) A characteristic of transition elements. 12 (c) A characteristic hydride formation by d-block elements. 13 (a) RBCs contain Fe in haemoglobin. 15 (d) Pt is a noble metal. 16 (c) ZnS (white), is precipitated in weak acidic medium ZnCl2 (aq.) and Zn(NO3 )2 (aq.) give strongly acidic solution. 17 (b) Zn, Cd, Hg are d-block elements but not regarded as transition elements because these do not have partially filled d-orbitals in their most common oxidation states 18 (b) The solubility order is AgF > AgCl > AgBr > AgI > Ag2S 19 (b) Brass is an alloy of copper and zinc (60 ― 80% Cu and 40 ― 20% Zn). 20 (c) Fe 2+ ⟶Fe 3+ + e; Mn 7+ + 5e ⟶Mn 2+
ANSWER-KEY Q. 1 2 3 4 5 6 7 8 9 10 A. B C B D A C D D D B Q. 11 12 13 14 15 16 17 18 19 20 A. B C A D D C B B B C