Classify the following into elements, compounds and mixtures .
a) Sodium b) Soil c) Sugar Solution d) Silver e) Calcium carbonate f) Tin g) Silicon h) Coal i) Air J) Soap k) Methane l) Carbondioxide m) Blood

Identify the solution among the following mixtures. a) Soil b) Sea Water c) Air d) Coal e) Soda water.

Which of the following materials fall in the category of a "pure substances"? Give reasons. (a) Ice (b) Milk (c ) Iron (d) Hydrochloric acid ( e) Calcium oxide (f) Mercury (g) Brick (h) Wood (f) Air

Write the formulae for the following compounds. a) Mercury (II) chloride b) Nickel (II) sulphate c) Tin (IV) oxide d) Thallium (I) sulphate e) Iron (III) sulphate f) Chromium (III) oxide.

Which separation techniques will you apply for the separation of the following ? (a) Sodium chloride from its solution in water. (b) Ammonium chloride from a mixture containing sodium chloride and ammonium chloride. ( c) Small pieces of metal in the engine oil of a car. (d) Different pigments from an extract of flower petals. (e) Butter from cards (f) Oil from water (g) Tea leaves from tea. (h) Iron pins from sand (i) Wheat grains from husk. (j) Find mud particles suspended in water.

classify the following processes into physical changes or chemical changes? (a) Twinkling of stars (b) Cooking of vegetables (c) Cutting of fruits (d) Boiling of waters. (e) Rusting of iron (f) Combustion of magnesium ribbon (g) Burning of candle (h) Melting of wax

How many of the following statements is (are) true about resonance. a) Resonance is an intramolecular process. b) Resonance involves delocalization both of s and p electrons. c) Resonance involves delocalization of pi electrons only. d) Resonance decreases potential energy of a molecule. e) Resonance has no effect on the potential energy of a molecule. f) Resonance is the only way to increase molecular stability. g) Resonance is not the only way to increase molecular stability. h) Any resonating molecule is always more stable than any nonresonating molecule. i) The canonical struture explains all features of a molecule. j) The resonance hybrid explains all features of a molecule. k) Resonating structures are real and resonance hybrid is imaginary. l) Resonance hybrid is real and resonating structures are imaginary. m) Resonance hybrid is always more stable than all canonical structures.

A compound (A) is greenish crystalline salt, which gave the following results. i) Addition of BaCl_(2) solution to the solution of (A) results in the formation of white ppt. (B). which is insoluble in dil HCL ii) On heating (A), water vapours and two oxides of sulphur, (C) and (D) are liberated leaving a red brown residue (E) iii) (E) dissolves in warm conc. HCI to give a yellow solution (F). iv) With H2S the solution (F) yields a pale yellow ppt. (G) which when filtered, leaves a greenish filtrate (H). v) Solution (F) on treatment with thiocynaate ions gives blood red coloured compound (I). Compound (A) is

A compound (A) is greenish crystalline salt, which gave the following results. i) Addition of BaCl_(2) solution to the solution of (A) results in the formation of white ppt. (B). which is insoluble in dil HCL ii) On heating (A), water vapours and two oxides of sulphur, (C) and (D) are liberated leaving a red brown residue (E) iii) (E) dissolves in warm conc. HCI to give a yellow solution (F). iv) With HS the solution (F) yields a pale yellow ppt. (G) which when filtered, leaves a greenish filtrate (H). v) Solution (F) on treatment with thiocynaate ions gives blood red coloured compound (I). White ppt (B) is of

A compound (A) is greenish crystalline salt, which gave the following results. i) Addition of BaCl_(2) solution to the solution of (A) results in the formation of white ppt. (B). which is insoluble in dil HCL ii) On heating (A), water vapours and two oxides of sulphur, (C) and (D) are liberated leaving a red brown residue (E) iii) (E) dissolves in warm conc. HCI to give a yellow solution (F). iv) With HS the solution (F) yields a pale yellow ppt. (G) which when filtered, leaves a greenish filtrate (H). v) Solution (F) on treatment with thiocynaate ions gives blood red coloured compound (I). The yellow solution is of