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ON THE WINGS OF EXCELLENCE CYCLE TEST-3 FOR CLASS X (2018-19) SCIENCE PAPER-3 (CHEMISTRY) TIME: 1 HOUR 15 MINUTES F.M: 50 Answer to this paper must be written on the paper provided separately. You will not be allowed to write during the first 10 minutes. This time is to be spent in reading the Question Paper. The time given at the head of this paper is the time allowed for writing the answers. The intended marks for the questions or parts of the questions are given in brackets [ ]. Question 1 (a) Give one test each to distinguish between the following pairs of chemicals: (i) Zinc nitrate solution and calcium nitrate solution. (ii) Sodium nitrate solutions and sodium chloride solutions. (iii) Iron(III) chloride solutions and copper chloride solutions. [6] (b) Three test tubes contain calcium nitrate solution, zinc nitrate solution and lead nitrate solution respectively. Each solution is divided in two portions (i) and (ii) Describe the effect of: (i) Adding sodium hydroxide solution to each portion in turn till it is in excess. (ii) Adding ammonium hydroxide solution to each portion in turn till it is in excess. [2] (c) Give the equations for the action of ZnO, PbO, and Al2O3 with conc. KOH solution. [3] (d) Write your observations as (a) to (j): [5] (i) (ii) (iii) (iv) (v) Test Methyl Orange Phenolphthalein Litmus Add Sodium carbonate Add Ammonium salt Acidic Soln. (a) (b) (c) (d) (e) Alkaline Soln. (f) (g) (h) (i) (j) Question 2 (a) You are provided with the following salts in separate test tubes: (i) FeSO4 (aq) (ii) aqueous Copper sulphate. What will you observe in each salt solution when Sodium hydroxide solution and Ammonium Hydroxide solution is added separately first in small amount then in excess? Support your answer with relevant chemical equations. [4] (b) X is a reddish brown element. When heated with dilute nitric acid, it gives out a colourless gas Y which turns into a reddish-brown gas on coming contact with air. A blue solution of a substance Z is also formed. The crystals of substance Z when heated give out the reddish brown gas along with another gas. A black residue M is left behind. (i) Name the substance X (ii) Write an equation for the reaction of substance X with dilute nitric acid and name the gas Y. (iii) Name the substance Z and M. Write an equation for the action of heat on substance Z [3] CHE/CT-3/2018-19/KSH This question paper consists of 2 printed pages Page 1
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