Tiêu đề DPP-3 SOLUTION.pdf ✅

CLASS : XIth SUBJECT : CHEMISTRY DATE : DPP No. : 3 1 (d) Bones contain Ca3 (PO4 )2 . 2 (c) It is a fact. 3 (b) It is a reason for given fact. 4 (d) It is a fact. 5 (a) Alkali metals’ family has closest resemblances in its members. 6 (c) Lithium and magnesium shows diagonal relationship. Some points of similarity are (i) Polarising power of Li + and Mg + are almost same. (ii) Like Li, Mg decomposes water very slowly. (iii) LiCl and MgCl2 are deliquescent. (iv) Like Li, Mg do not form solid bicarbonates. 7 (c) LiOH < NaOH < KOH < RbOH Down the group basic character increases 8 (c) Sodium bicarbonate decomposes on strong heating and gives sodium carbonate. 2NaHCO3 ∆ Na2CO3 + CO2 + H2O 9 (a) Fusion mixture contains K2CO3 and Na2CO3. 10 (d) Mg + 2HCl⟶MgCl2 + H2 ; EOPMg > EOPH 11 (a) Topic :- THE S-BLOCK ELEMENTS Solutions
Baking powder contains NaHCO3, Ca(H2PO2 )2 and starch. 12 (d) Plaster of Paris absorb water to form monoclinic gypsum which is a hard substance. CaSO4 . 1 2 H2O 3/2H2O CaSO4 .2H2O monoclinic gypsum 13 (a) Li and Mg show diagonal relationship. 14 (d) It is a fact. 15 (c) ∵ Carbon dioxide does not help in burning and it reacts with alkali metals to form carbonates. ∴ CO2 is used to extinguish fire of lithium, sodium and potassium. 16 (d) Halides of alkaline earth metals possess all these properties. 17 (c) Le blanc method is for the manufacture of Na2CO3. 18 (b) Thomas slag is Ca3 (PO4 )2 . It is used as a fertilizer. It has 14-18% of P2O5. 6CaO + P4O10 ⟶2Ca3 (PO4 )2 phosphatic slag or Thomas slag 19 (c) Norwegian saltpetre is basic calcium nitrate. 20 (a) Alkali and alkaline earth metals are extracted by the electrolysis of their fused salt.
ANSWER-KEY Q. 1 2 3 4 5 6 7 8 9 10 A. D C B D A C C C A D Q. 11 12 13 14 15 16 17 18 19 20 A. A D A D C D C B C A