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Chemistry PAPER -1 (THEORY) (Two Hours) (Candidates are allowed additional 15 minutes for only reading the paper. They must not start writing during this time.) ____________________________________________________________________________________________ Answer all questions in Section I and four questions from Section II. All working including rough work should be done on the same sheet as, and adjacent to, the rest of the answer. The intended marks for questions or parts of questions are given in brackets [ ]. A list of useful physical constants is given Avagadro s No = 6.023 1023 SECTION I (40 Marks) Attempt all questions from this Section Question 1 (a) Choose the most appropriate answer. (i) Which of the following is a common characteristic of a covalent compound? A High melting point. B Conducts electricity when it is in the molten state. C Consists of molecules. D Always soluble in water. (ii) Ammonium hydroxide will produce a reddish brown precipitate when added to a solution of : (iii) A CuSO4 B Zn(NO3)2 C FeSO4 D FeCl3 A salt which in solution gives a bluish white precipitate with NaOH solution and a white precipitate with BaCl2 solution is: A B C D CuSO4 FeSO4 Fe2 (SO4)3 CuCl2 (iv) The ratio between the masses of equal volumes of gas and hydrogen under same conditions of temperature and pressure is: (v) (vi) (vii) A Avogadro s Law B moles C Vapour density D Molecular mass During the electrolysis of acidified water which of the following takes place: A Oxygen is released at cathode. B Oxygen is released at anode. C Hydrogen is released at anode. D Sulphur dioxide is released at anode. Ore of Iron is: A Haematite B Cryolite C Cinnabar D Galena Hydrogen chloride can be obtained by adding concentrated Sulphuric acid to: A NaCl B Na2SO4 C Na2CO3 D NaNO3. (viii) Which of the following reactions gives copper as a product (ix) A Passing dry ammonia over heated copper oxide. B Adding dilute hydrochloric acid to copper oxide. C Heating copper oxide. D Passing oxygen over heated copper oxide? Formation of chloroform from methane and chlorine is an example of: A Addition B Dehydration C Substitution 2 D (x) (b) Elimination. The element with the highest ionization potential in the periodic table is: A He B Ne C Ar D Xe [10] 1) Calculate the percentage of phosphorous in Calcium Hydrogen phosphate Ca (H2PO4)2 (At. Mass of P= 31, O=16, H=1 and Ca= 40) 2) A compound with empirical formula AB has vapor density three times its empirical formula weight. Find its molecular formula. (c) (d) (e) [5] Name the organic compound prepared by each of the following reactions: (i) CH3 COONa + NaOH (ii) CaC2 + H2O (iii) C2H5Br + KOH (alc) (iv) C2H2 + Br2 (v) C2H2 + Cl2 CaO [5] Identify the following substances: (i) An acidic gas which gives dense white fumes with NH3. (ii) An alkane which can also be called a greenhouse gas. (iii) A solid which when kept in the open, forms a solution after sometime. (iv) A substance used to reduce the temperature during the electrolytic reduction of alumina. (v) A metal which gives hydrogen gas on reacting with both dilute acid and alkali. [5] Write equations for the following reactions: (i) Aluminium oxide and Sodium hydroxide. (ii) (iii) Zinc and dilute sulphuric acid. Nitrogen dioxide and water. (iv) Concentrated sulphuric acid and sugar. (v) Copper with concentrated nitric acid. [5] 3 (f) (g) Name the following: (i) Second member of alkene series (ii) First member of alkane series (iii) Third member of aldehyde series. (iv) Second member of carboxylic acid. (v) Fourth member of alcohol series. [5] Write the I.U.P.A.C. names of the following compounds: O (i) H || C H O (ii) (iii) (iv) || H3C H CH3 C H OH H C C C H H H C2H5 H H O C H C2H5 CH3 (v) H3C C [5] CH3 CH3 4 SECTION II (40 Marks) Attempt any four questions from this Section. Question 2. (a) The following questions refer to the periodic table: (i) Name the second last element of the period 3. (ii) How many elements are in the second period? (iii) Name the element which has the highest electron affinity. (iv) Name the element which has the highest electro negativity. (v) (b) Name the element which may be placed on group 1 but is not a metal. [5] Fill in the blanks using the correct options: (i) Metals have ionisation potential. (low/ high) (ii) Group 18 elements have ------ valence electrons (4 / 8) with the exception of --- ( He / Ne) with -------- electrons (2 / 8) in valence shell. (iii) Group 2 elements are called ----- metals (alkali / alkaline earth). [5] Question 3. (a) (b) Draw different isomers having the following molecular formula: (i) C5H12 (chain) (ii) C4H8 (position). [5] Answer the following questions related to industrial manufacture of ammonia: (i) Name the process used to prepare ammonia. (ii) Give the reaction used to produce ammonia. (iii) What are the favorable conditions used to produce ammonia? (iv) How is ammonia recovered? [5] Question. 4 (a) Name the method by which following compounds can be prepared: Select the appropriate method from the following list: Neutralization; direct combination; precipitation; metal + acid use a method only once. (i) Sodium sulphate (ii) Silver chloride (iii) Iron sulphide. [3] 5 (b) How will you distinguish between following pairs of compounds using NH4OH. (i) Copper sulphate and iron (II) sulphate. (ii) Zinc nitrate and lead nitrate. (iii) Iron (II) sulphate and iron (III) sulphate. (c) [3] Name: (i) A greenish yellow gas with pungent smell. (ii) An oxide which is yellow when hot and white when cold. (iii) A chemical used to deplete ozone layer. (iv) A drying agent used to dry ammonia gas. [4] Question. 5 (a) Give the chemical equations for the following reactions: (i) Laboratory preparation of nitric acid (ii) Catalytic oxidation of ammonia (iii) Carbon reacts with concentrated nitric acid (iv) Copper reacts with dilute nitric acid (b) (v) Action of heat on lead nitrate [5] (i) Name the chief ore of aluminium. (ii) Name the process used to concentrate the above mentioned ore. (iii) Why is cryolite added to ammonia in the electrolytic reduction of aluminium? (iv) Give cathode and anode reactions involved in extraction of aluminium from its above mentioned ore. (v) Why is powdered coke sprinkled over the surface of electrolytic mixture? [5] Question 6. (a) Draw a neat and well labelled diagram for the silver plating on an iron spoon. (b) Copy and complete the following table related to electrolysis. S.No. Name of Electrolyte Name of Cathode Name of Anode 1. CuSO4 (aq.) Copper Copper 2. PbBr2 (molten) Platinum Platinum Product at Cathode [3] Product at Anode [4] 6 (c) Classify the following as oxidation and reduction reaction, also complete the reaction. (i) Cu Cu2+ (ii) Fe3+ Fe2+ (iii) Cl- Cl [3] Question. 7 (a) A compound has the following percentage composition by mass: Carbon 54.55%, Hydrogen 9.09% and Oxygen 36.26%. Its vapour density is 44. Find the Empirical and Molecular formula of the compound. (H = 1; C = 12; O = 16) (b) (c) [5] Give the electron dot structure of the following: (i) NH3 (ii) CH4 (iii) H3O+ [3] Compare the properties of covalent and electrovalent compounds on the following points: (i) Solubility (ii) Structure. [2] 7
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