Differentiate between the following pairs of compounds using the reagent given in the bracket:
(a) Ammonium chloride and Sodium chloride (using an alkali)
(b) Zinc Nitrate solution and Calcium Nitrate solution (using excess sodium hydroxide solution)
(a) When ammonium chloride is reacted with an alkali like NaOH, the colourless gas ammonia having a sharp pungent characteristic smell is evolved. Whereas, sodium chloride (NaCl) does not show any reaction with alkali.
\mathrm{NH_4Cl + NaOH \rightarrow NH_3 \uparrow + NaCl + H_2O} \mathrm{NaCl + NaOH \rightarrow No\ reaction}(b) Add sodium hydroxide (NaOH) solution first drop by drop and then in excess.
Zinc Nitrate solution: A white gelatinous precipitate of zinc hydroxide forms, which dissolves in excess NaOH to give a clear solution.
Calcium Nitrate solution: A white precipitate of calcium hydroxide forms and remains insoluble even in excess NaOH.
More ICSE Moderate level questions
Complete the following sentences by choosing the correct word(s) from the brackets: (a) ............... solution forms a coloured precipitate with ammonium hydroxide which is soluble in excess of ammonium hydroxide. [Ferrous chloride / Copper nitrate] (b) Zinc blende is converted to zinc oxide by ................ [Calcination / Roasting] (c) ............... conducts electricity by the movement of ions. [Molten iron / Molten sodium chloride] (d) The reaction that takes place at the anode during the electrolysis of aqueous Sodium argentocyanide with silver electrodes is ................ [Ag ⟶ Ag+ + e-/ Ag+ + e- ⟶ Ag] (e) The salt formed when ZnO reacts with hot concentrated NaOH is ............... . [sodium zincate / zinc hydroxide]
Rohit took two different salt solutions in test tubes C and D as shown in the figure below. He added dilute HCl to each of the two test tubes. The products formed in the test tubes C and D are silver chloride and lead chloride respectively. State: (a) one common observation made by Rohit in both the reactions. (b) the observations made by him on addition of excess of ammonium hydroxide to the products formed in: 1. test tube C 2. test tube D
Match the Column A with Column B: Column A Column B (a) N2 + 3H2 ⇌ 2NH3 1. Vanadium Pentoxide (b) 4NH3 + 5O2 ⟶ 4NO + 6H2O 2. Nickel (c) 2SO2 + O2 ⇌ 2SO3 3. Iron (d) C2H4 + H2 ⟶ C2H6 4. Concentrated Sulphuric acid (e) CuSO4.5H2O ⟶ CuSO4 + 5H2O 5. Platinum
Give one significant observation when: (a) Barium chloride solution is added to zinc sulphate solution. (b) Lead nitrate is heated strongly. (c) Chlorine gas is passed through moist starch iodide paper.
Identify only the anion present in the following compound: (a) The compound on heating produces a colourless, odourless gas which turns lime water milky and has no effect on acidified potassium dichromate solution. (b) The solution of the compound which on treating with concentrated sulphuric acid and freshly prepared ferrous sulphate solution produces a brown ring.
Identify the cation in each of the following cases: (a) Ammonium hydroxide solution when added to Solution B gives a white precipitate which does not dissolve in excess of ammonium hydroxide solution. (b) Sodium hydroxide solution when added to Solution C gives a white precipitate which is insoluble in excess of sodium hydroxide solution.
Alex was given a solution of an unknown salt Y for analysis. He performed the following tests and recorded his observations: To a part of the solution Y, he added silver nitrate solution and obtained a white precipitate which was soluble in ammonium hydroxide solution. To the remaining solution he added a few drops of sodium hydroxide solution and obtained a pale blue precipitate. Based on the observations made by Alex, identify: (a) the anion and (b) the cation present in salt Y.
Rita was given an unknown salt for identification. She prepared a solution of the salt and divided it into two parts. To the first part of the salt solution, she added a few drops of ammonium hydroxide and obtained a reddish-brown precipitate. To the second part of the salt solution, she added a few drops of silver nitrate solution and obtained a white precipitate. Name: (a) the cation present and (b) the anion present in the salt given for identification.
State one relevant observation for each of the following: (a) To the copper nitrate solution, initially few drops of sodium hydroxide solution is added and then added in excess. (b) Burning of ammonia in excess of oxygen. (c) Dry ammonia gas is passed over heated PbO.
Fill in the blanks with the choices given in the brackets: (a) Metals are good ............... [oxidizing agents /reducing agents] (b) Non-polar covalent compounds are ............... [good / bad] conductors of heat and electricity. (c) Higher the pH value of a solution, the more is ............... [acidic / alkaline] it is. (d) ............... [Silver chloride / Lead chloride] is a white precipitate that is soluble in excess of Ammonium hydroxide solution. (e) Conversion of ethene to ethane is an example of ............... . [hydration / hydrogenation]
Complete the following sentences by choosing the correct option from the brackets: (a) The oxide that dissolves in caustic potash (KOH) is ............... . [ZnO / CuO] (b) The reaction that takes place at the anode during the electrolysis of molten lead bromide is ............... . [2Br − 2e− ⟶ 2Br− / 2Br− − 2e− ⟶ Br2] (c) The volume occupied by 8 grams of oxygen gas at STP is ............... litres. [5.6 / 8.96] [Atomic weight of O = 16] (d) ............... does not give hydrogen gas when it reacts with cold and very dilute nitric acid. [Cu / Mn] (e) ............... is a polar covalent compound. [HCl / CCl4]
Identify the following terms / compounds: (a) A compound which reacts with water to give acetylene gas. (b) The gas evolved when sodium propanoate is heated with soda lime. (c) A reddish-brown precipitate formed when ferric chloride solution reacts with an alkali. (d) A pair of electrons present in an atom which is not shared with any other atom during bond formation. (e) The relative molecular mass of a substance expressed in grams.
