Title DPP-10 SOLUTION.pdf ✅

CLASS : XIth SUBJECT : CHEMISTRY DATE : DPP No. : 10 1 (c) Laminaria-a sea-weed containing iodine as iodide. 2 (b) It is a fact. 3 (a) Yellow P is readily oxidized in air and thus, kept in water. 4 (a) N2 does not combine directly with F2. 5 (d) Lowest bond dissociation energy is of I2. 6 (a) 5O3 + I2 + H2O⟶2HIO3 + 5O2 7 (d) This is a use of molten Na and S. 8 (d) Catalyst has no role in oxidation by HNO3. 9 (a) In the froth- floatation process, froths are produced by blowing air through water containing pine oil and ore. Ore particles are not wetted by water, hence these being lighter, comes out to the surface with froths and extracted . The impurities are watted by water and becomes heavy .Thus, these settle down. 10 (a) XeF6 + 3H2O⟶XeO3 + 6HF 11 (d) Zero group members are less abundantly found and thus, called as rare gases; due to their least reactivity they are called inert gases; on account of some compounds formed by Kr, Xe, they are named noble gases. 12 (a) Xe in XeOF4 has sp 3d 3 -hybridisation with one lone pair of electron. Topic :-THE P-BLOCK ELEMENTS-2 Solutions
13 (a) Hypophosphorous acid is a monobasic acid as it forms one type of salts e.g. sodium hydrogen phophite (NaH2PO2) NaOH+ H3PO2⟶NaH2PO2+H2O Hydrophosphorus acid has two hydrogen atoms attached to phosphorus and one hydrogen atom attached to oxygen atom(which is ionisable), i.e., 14 (a) X + e ⟶ X ―; ∆H = ―A; X ― ⟶X + e; ∆H = +A. 15 (a) Oxidizing nature of oxides decreases with increasing oxidation number of central atom. 16 (d) Oswald process of manufacturing of HNO3 4NH3+5O2 Pt 4NO+6H2O+heat 2NO+O2 50°C 2NO2(g) 3NO2+H2O⟶2HNO3+NO ∴ Pt is catalyst in Oswald process. 17 (b) 4HNO3+P4O10⟶4HPO3+2N2O5 Dinitrogen pentoxide The product is dinitrogen pentoxide (N2O5) 18 (b) Phosphorus acid (H3PO3)is a diprotic acid . It forms two series of salt such as NaH2 PO3 and Na2 HPO3 but none of the type NaPO3 with NaOH. Its structure is as 19 (b) +4 +5 2 NO2 + H2O⟶HNO2+ HNO3 mixed acid anhydride 20 (a) Ba3N2 ∆ 3Ba + N2 P O H OH H P H OH OH O
ANSWER-KEY Q. 1 2 3 4 5 6 7 8 9 10 A. C B A A D A D D A A Q. 11 12 13 14 15 16 17 18 19 20 A. D A A A A D B B B A