Tiêu đề DPP-8 SOLUTION.pdf ✅

CLASS : XIth SUBJECT : CHEMISTRY DATE : DPP No. : 8 1 (a) The formation of ozone from oxygen is an endothermic reaction not exothermic reaction. So, statement Is not correct statement. 2 (b) NH4NO3→N2O + 2H2O (Laughing gas) 3 (c) P2O5 is solid acidic oxide. 4 (a) KNO3 ∆ KNO2 + 1 2 O2 5 (c) (NH4 )2 SO4 + KCNO→NH4CNO + K2SO4 ↓ NH2CONH2 urea 6 (d) AgI is insoluble in NH4OH. 8 (a) The structure of phosphorous acid H3PO3 is as follows As it has two —groups, hence it shows dibasic character 9 (a) The thermal stability of the hydrides of nitrogen family or group15 elements decreases on HO P OH H O Topic :-THE P-BLOCK ELEMENTS-2 Solutions
moving downwards in the group. Therefore, NH3is the most stable and BiH3is the least stable. The stability of the hydride of group 15 elements decreases in the order. NH3>PH3>AsH3>SbH3> BiH3 10 (d) The electropositive character increases down the group, eg., I(CH3COO)3 ,IPO4, etc., are ionic. 12 (c) K2CS3 is potassium thiocarbonate. 13 (a) Only H2S2O6contains S—S bond. Its structure is 14 (a) Orthophosphoric acid(H3PO4) is a tribasic acid. Hence, its structure can be represented as O⟵P(OH)3. (lp + σbp = 1 + 3 = 4) Hence hybridization of p in H3PO4 is sp3 and thus it is tetrahedral in shape. 15 (b) Cl2 + H2O⟶2HCl + [O] 16 (a) Clatherate formation involves dipole induced dipole attraction ( ∵ water is polar molecule and Xe is non ― polar). 17 (b) Divers use He + O2 mixture for respiration in place of N2 + O2. The N2 was found to dissolve in blood at high pressure during diving and after it, the N2 gas comes out from blood causing painful nerve bursting. The mixture is also used for respiration by asthma patients. 18 (d) Ammonium nitrate on heating at 250°C gives N2O. 19 (c) F2 has low reactivity for Cu and steel. 20 (a) HO S O O S O O OH O P O O H H H O
Due to the formation of thin oxide film on iron surface. ANSWER-KEY Q. 1 2 3 4 5 6 7 8 9 10 A. A B C A C D B A A D Q. 11 12 13 14 15 16 17 18 19 20 A. C C A A B A B D C A