Chemistry
The following materials are provided – solutions of cobalt chloride, ammonia, potassium permanganate, lime water, starch-iodide, sodium hydroxide, lead acetate, potassium iodide. Also provided are litmus and filter papers, glowing splinters and glass rods. Using the above how would you distinguish between :
(a) a neutral, acidic and a basic gas
(b) oxygen and hydrogen gas
(c) carbon dioxide and sulphur dioxide gas
(d) chlorine and hydrogen chloride gas
(e) hydrogen sulphide and nitrogen dioxide gas
(f) ammonia and carbon dioxide gas
(g) zinc carbonate and potassium nitrate
(h) hydrated copper sulphate and anhydrous copper sulphate
(i) ammonium sulphate and sodium sulphate.
Related Questions
Distinguish between the following pairs of compounds using a reagent as a chemical test:
(i) Calcium nitrate and Zinc nitrate solution
(ii) Magnesium chloride and Magnesium nitrate solution
Identify the salts P, Q, R from the following observations:
(i) Salt P has light bluish green colour. On heating, it produces a black coloured residue. Salt P produces brisk effervescence with dil. HCl and the gas evolved turns lime water milky, but no action with acidified potassium dichromate solution.
(ii) Salt Q is white in colour. On strong heating, it produces buff yellow residue and liberates reddish brown gas. Solution of salt Q produces chalky white insoluble ppt. with excess of ammonium hydroxide.
(iii) Salt R is black in colour. On reacting with conc. HCl, it liberates a pungent greenish yellow gas which turns moist starch iodide paper blue black.
Give a chemical test to distinguish between the following:
(i) Sodium carbonate and sodium sulphate
(ii) Potassium chloride and potassium nitrate
(iii) Copper carbonate and copper sulphite
(iv) Lead chloride and lead sulphide
(v) Iron (II) sulphate and iron (III) sulphate
(vi) Calcium sulphate and zinc sulphate
(vii) Lead nitrate and zinc nitrate
(viii) Copper sulphate and calcium sulphate
(ix) Manganese dioxide and copper (II) oxide
(x) dil. HCl, dil. HNO3, dil. H2SO4.
[explain the procedure for the preparation of the solutions for the above tests wherever required]
Identify the cation [positive ion] and anion [negative ion] in - A, B and C. Also identify P, Q, R, S, T, U, V, W.
(a) Substance 'A' is water soluble and gives a curdy white precipitate 'P' with silver nitrate solution. 'P' is soluble in ammonium hydroxide but insoluble in dil. HNO3. Substance 'A' reacts with ammonium hydroxide solution to give a white precipitate 'Q' soluble in excess of NH4OH.
(b) A solution of substance 'B' is added to barium chloride solution. A white ppt. 'R' is formed, insoluble in dil. HCl or HNO3. A dirty green ppt. 'S' is formed on addition of ammonium hydroxide to a solution of 'B' and the precipitate is insoluble in excess of ammonium hydroxide.
(c) Substance 'C' is a coloured, crystalline salt which on heating decomposes leaving a black residue 'T'. On addition of copper turnings and conc. H2SO4 to 'C' a coloured acidic gas 'U' is evolved on heating. A solution of 'C' is added to NaOH soln. until in excess. A pale blue ppt. 'P' is obtained insoluble in excess of NaOH. A solution of 'C' is then added to NH4OH soln. in excess to give an inky blue solution 'V'. A solution of 'C' is warmed and hydrogen sulphide gas is passed through it. A black ppt. 'W' appears.