CBSE Area

An organic acid �X� is a liquid which often freezes during winter time in cold countries, has the molecular formula, C2H4O2. On warming   it with ethanol in the presence of a few drops of concentrated  sulphuric acid, a compound �Y� with a sweet smell is formed   (i) Identify �X� and �Y�. (ii) Write a chemical equation for the reaction involved. (i) The organic acid X is ethanoic acid (CH 3 COOH) and The compound Y is ethyl Ethanoate CH 3 � COOH + CH 3 � CH 2 OH ---------->  (CH 3  �  C � O � CH 2 � CH 3 ) II O Write name of the following � i.   Alkaline earth metal belonging to the third period ii.   The alkali metal atom having largest atomic radius iii.   The halogen atom belonging to fourth period iv.   The element having lowest ionization energy v.   The element having second lowest electronegativity    i.   Magnesium   ii.   Franciu...

10th Chemistry : Soaps and Detergents [Carbon and Its Compound]   SOAPS Metallic salts prepared from natural fats are called soaps. Soap is a sodium salt or potasium salt of long chain fatty acids that has cleansing action in water. Sodium stearate, sodium oliate and sodium  palmitate are some examples of soaps. Stearic acid is a long chain fatty acid. Its formula is C 17 H 35 COOH. This reacts with sodium hydroxide to give a compound called sodium stearate, which has properties of soap. Similarly, sodium hydroxide reacts with oleic acid and palmitic acid forming sodium oleate   (C 17 H 33 COONa) and sodium palmitate (C 17 H 31 COONa) respectively. Please Note! Fatty acids are organic compounds. The molecules of these compounds contain a carboxyl  group                 {-COOH}. These molecules react with a trihydric alcohol called glycerol to form a class of compounds called esters. Groundnut oil, coconut oi...

10th Carbon and its compounds_ CBSE_NCERT Class Xth  (a) Alkanes are gas (C 1 to C 4 ) ; liquid (C 5 to C 17 ) and rest are solid at room temperature. (b) The melting and boiling point of Alkanes increases with increase in number  of C  � atom in Alkanes . Alkane Formula Boiling point [�C] Melting point [�C] State (at 20 �C) Methane CH 4 -162 -182 gas Ethane C 2 H 6 -89 -183 gas Propane C 3 H 8 -42 -188 gas Butane C 4 H 10 0 -138 gas Pentane C 5 H 12 36 -130 liquid Hexane C 6 H 14 69 -95 liquid Heptane C 7 H 16 98 -91 liquid Octane C 8 H 18 126 -57 liquid Nonane C 9 H 20 151 -54 liquid Decane C 10 H 22 174 -30 liquid Undecane C 11 H 24 196 -26 liquid Dodecane C 12 H 26 216 -10 liquid Hexadecane C 16 H 34 281 18 liquid Icosane C 20 H 42 343 37 solid Triacontane C 30 H 62 450 66 solid Tetracontane ...