Formatting page ...
CHEMISTRY Section A ( attempt all questions) Question 1 a)Name the following: [5] 1. Liquor ammonia fortis is a saturated solution of 2. Process by which impurities from metal are removed electrically 3. A gaseous hydrocarbon used for welding purpose 4. Among the period 2 elements ,the element which has highest electron affinity is 5. A metal with dull appearance b) Identify the following gases[5] 1. The gas evolved on reaction of Aluminium with boiling concentrated caustic alkali solution. 2. The gas produced when excess ammonia reacts with chlorine 3. A gas which turns acidified potassium dichromate paper clear green. 4. The gas produced when copper reacts with concentrated nitric acid 5. The gas produced on reaction of dilute sulphuric acid with a metal sulphide. c)Give reasons for the following:[5] 1. Alkali metals are good reducing agents. 2. Hydrogen chloride gas cannot be dried over quick lime. 3. Bond formed in hydrogen molecule is non-polar covalent bond. 4. Almost 90% of all known compounds are organic in nature. 5. Copper, though a good conductor of electricity is a nonelectrolyte d)Write the balanced chemical equations for the following:[5] 1. Burning of methane in sufficient supply of air. 2. Lead nitrate solution is added to sodium chloride solution. 3. Zinc is heated with sodium hydroxide solution. 4. Ethyl chloride reacts with aqueous potassium hydroxide. 5. Ferric hydroxide with nitric acid. e)Solve the following: 1. An acid of phosphorus has the following percentage composition:[3] 47% of hydrogen,38.27% of phosphorus,59.26% of oxygen .Find the empirical formula of this acid and its molecular formula . Given that its relative molecular mass is 162. 2. 67.2 liters of hydrogen combines with 44.8 liters of nitrogen to form ammonia under specific conditions as:[2] N2 + 3H2 > 2NH3 Calculate the volume of ammonia produced .What is the other substance if any, that remains in the resultant mixture? f)State what do you observe when:[5] 1. Sulphur dioxide is slowly passed through potassium permanganate solution. 2. Silver nitrate solution is mixed with sodium chloride solution. 3. Sodium hydroxide solution is slowly added to lead nitrate solution. 4. Sulphur dioxide solution is passed through lime water. 5. Red lead is heated. g)write the structures of the following compound:[5] 1. Prop-1-ene 2. 3-hexene 3. 2-methylbutane 4. 2-methylprop-1-ene 5. Pent-2-ol h) The following questions are related with the electrolysis of acidulated water:[5] 1. Name the products obtained at cathode and anode. 2. What is the ratio of the products formed at cathode and anode. 3. Give the equations for the reactions taking place at cathode and anode. 4. why is this considered to be an example of catalysis. Section B Question 2 (a)[5] 1. Name the process by which nitric acid is manufactured. 2. Give the equation involved during the process. 3. Why the gas must be cooled before they enter into the oxidation chamber. 4. Why is iron rendered passive with fuming of nitric acid (b)[5] Industrially ammonia is obtained by direct combination between nitrogen and hydrogen. (1) Write the balanced chemical equation is for the reaction (2) Is the formation of ammonia promoted by high or low pressure? (3) How is ammonia collected? (4) What property of ammonia is demonstrated by fountain experiment? (5) Write correctly balanced equation for ammonia and sulphuric acid. Question 3 (a)[5] Arrange the following as per the instructions given below: 1. Cs, Na, Li, K, Rb (increasing order of metallic character) 2. Mg, Cl, Na, S, Si (decreasing order of atomic size) 3. Na, K, Cl, S, Si (increasing order of ionization energy) 4. Cl, F, Br, I (increasing order of electron affinity) 5. B, O, Ne, Li, C (increasing order of valance electrons) (b)[5] (1) A covalent compound which behaves like an ionic compound in aqueous solution. (2)Fill in the blanks 1. In covalent compounds, the bond is formed is due to the __________ of electrons. 2. Electrovalent compounds have ____________ boiling point. 3. By drawing an electron dot diagram, show the lone pair effect leading to the formation of ammonia ion from ammonia gas and hydrogen gas. Question 4. Question 4 (a)[6] 1.The sketch below illustrates the refining of alluminium by Hoope s process 1. 2. 3. 4. What is the electrolyte in the tank? What material is used for cathode? Give the reactions taking place at cathode and anode? Give the main ore of iron and aluminium with their chemical formula (b)[4] Identify the anion present: 1. When dilute sulphuric acid is added to the salt solution A rotten egg smelling gas is evolved.It turns moist lead acetate paper black. 2. Compound B on heating with copper tunings and concentrated sulphuric acid liberates a reddish brown gas. 3. Compound C on reaction with dilute sulphuric acid liberates a gas which turns lime water milky, but has no effect on acidified potassium dichromate solution. 4. When a solution of compound D is treated with silver nitrate solution a white precipitate is obtained which is soluble in ammonium hydroxide solution Question 5 (a)[4] Distinguish between the following pairs 1. Roasting and Calcination 2. Ethylene and Acetylene (chemical test) 3. Hydrogen chloride gas and Hydrogen sulphide gas( chemical test) 4. Saturated and Unsaturated hydrocarbons (b)[4] Give the chemical equations to show the following property of sulphuric acid 1. 2. 3. 4. Non-volatile property Oxidizing agent Dehydrating agent As a dibasic acid (c) [2] Define Avogadro s law and Electronegativity
|
