While carrying out a flame test on a compound W, a bluish flame is observed and on heating W, the compound decomposes producing a brown gas X and another gas Y, that rekindles a glowing splint.

Here are the solutions to your chemistry questions: b) (i) Step 1: Identify the cation responsible for a blue flame in a flame test. A blue flame is characteristic of copper ions. The cation in compound W responsible for the blue flame is Copper (Cu^2+). b) (ii) Step 1: Identify Gas X based on its color. A brown gas is typically nitrogen dioxide. Step 2: Identify Gas Y based on its property. A gas that rekindles a glowing splint is oxygen. Gas X: Nitrogen dioxide (NO_2) Gas Y: Oxygen (O_2) b) (iii) Step 1: Deduce the compound based on the cation and decomposition products. Compound W contains copper (from the blue flame) and decomposes to produce nitrogen dioxide and oxygen, which is characteristic of a metal nitrate. Compound W is Copper(II) nitrate (Cu(NO_3)_2). b) (iv) Step 1: Write the balanced chemical equation for the decomposition of copper(II) nitrate. When heated, copper(II) nitrate decomposes into copper(II) oxide, nitrogen dioxide gas, and oxygen gas. 2Cu(NO_3)_2(s) 2CuO(s) + 4NO_2(g) + O_2(g) c) (i) Step 1: Identify the ion that forms a white precipitate with BaCl_2. The formation of an immediate white precipitate upon adding BaCl_2 solution indicates the presence of sulfate ions, as barium sulfate (BaSO_4) is insoluble. The likely ion present in solution is Sulfate ion (SO_4^2-). c) (ii) Step 1: Identify the gas evolved and the ion present. Effervescence producing a colourless gas that decolorises acidified KMnO_4 indicates the presence of sulfur dioxide (SO_2) gas, which is produced from sulfite ions (SO_3^2-). Step 2: Describe a simple laboratory test for sulfur dioxide. Gas evolved: Sulfur dioxide (SO_2) Ion present: Sulfite ion (SO_3^2-) Test: Pass the gas through acidified potassium dichromate(VI) solution; the orange solution turns green. c) (iii) Step 1: Identify the gas commonly used in fire extinguishers. The gas commonly used in fire extinguishers is carbon dioxide (CO_2). Step 2: Describe a simple laboratory test for carbon dioxide. Gas evolved: Carbon dioxide (CO_2) Test: Pass the gas through limewater (calcium hydroxide solution); it turns milky/cloudy. Last free one today — make it count tomorrow, or type /upgrade for unlimited.