Tiêu đề DPP-10 SOLUTION.pdf ✅

CLASS : XIth SUBJECT : CHEMISTRY DATE : DPP No. : 10 1 (b) Bleaching powder is obtained by treating chlorine with slaked lime. Ca(OH)2 + Cl2 →CaOCl2 + H2O Slaked lime bleaching powder 2 (c) Siedlitz powder contains NaHCO3. 3 (d) NaHCO3 is manufactured as byproduct in Solvay process for Na2CO3. 4 (c) It is a reason for given fact. 5 (b) Na2O2 + 2H2O →H2O2 + 2NaOH 2H2O2 NaOH 2H2O + O2 Water used during the reaction reacts with Na2O2 to from NaOH which tends to decompose H2O2. 6 (a) A characteristics of alkali metals. 7 (a) It is a reason for given fact. 8 (b) When CO2 gas is passed through a brine solution (28% NaCl) saturated with ammonia, it gives sodium bicarbonate which on drying and heating gives sodium carbonate. 9 (c) In Down process, sodium is manufactured by the electrolysis of fused sodium chloride in the presence of CaCl2 and KF using graphite anode and iron cathode. NaCl ⇌Na + + Cl ― Topic :- THE S-BLOCK ELEMENTS Solutions
Na + + e ― ⟶Na (at cathode) 2Cl ― →Cl2 + 2e ―(at anode) CaCl2 +KF lower the melting point from the 1085 K to 850 K. 10 (d) From Be to Ba ionic character increases 11 (a) Mg combines directly with N2. 12 (d) It is a fact. 13 (c) On moving down the group, lattice energy remains almost constant as the sulphate is so big that small increase in size of the cations does not make difference. Hydration energy causes decrease in the solubility of the sulphates as the ionic size increases. Thus, the correct order is Be > Mg > Ca > Sr > Ba 14 (b) It is a reason for given fact. 16 (c) 4S + 6NaOH⟶Na2S2O3 + 2Na2S + 3H2O 18 (a) On fusion ions are separated from each other. NaH ∆ Na + + H ― 19 (a) Plaster of Paris CaSO4 . 1 2 H2O, gypsum CaSO4. 2H2O. 20 (d) Mg alloys are lighter.