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CHEMISTRY (SCIENCE PAPER -2) Maximum Marks: 80 Time allowed: Two hours Answers to this Paper must be written on the puper provided sepurutel Yon will not he allowed to write during first 15 minules This time is to be spent in reading the question paper. The time given at the head ofthis P'uper is the time allowedfor writing the amswers. Section A is compulsory. Atempt any four questions from Section B The intended marks for questions or parts ofquestions are given in brackets [ ) SECTION A (40 Marks) (Atempt all questions from this Section) Question 1 Choose the correct answers to the questions from the given options. 15 (Do not copy the questions, write the correct answers only.) An clement.in period 3, whose electron affinity is zero: (ii) (a) Neon (b) Sulphur (c) Sodium (d) Argon An clement with the largest atomic radius among the following is: (a) Carbon (b) Nitrogen (c) ithium (d) Beryllium This paper consists of 1l printed pages and I blank page. T23 522 CCopyright reserved Turn Over The compound that is not an ore of aluminium Ctyoite (a) Comdum (C) luorspa () auxite (IN) The vapour density of ClOI is (At. W. C-12, H-1, 0-16) (a) () b) 18 () 16 (d) 34 Which of the following of an article with silver? (a) Ag-1e reactions takes place at the anode during the electroplating Ag (b) Ag+ le Ag' (C)Ag-1le (d) (vi) Ag None of the above The metallic hydroxide which forms a deep inky blue solution with excess ammonium hydroxide solution is: (a) Fe(OH2 (b) Cu(OH)2 (c) Ca(OH) (d) Fe(OH) (Vii) An example of a cyclic organic compound is: (a) Propene (b) Pentene (c) Butene (d) Benzene (i) (x) In the laboratory preparation, HCI gas (a) dilute (6) concentrated sulphuric acid (c) diluie (d) acidified water The nitrate nitric is dried by passing thrOugh acid sulphuric which acid thermal decomposition leaves behind a residue which when hot and white when cold (x) on (a) Lead nitrate (b) Ammonium nitrate (c) Copper nitrate (d) Zinc nitrate The salt formed when (a) concentrated sulphuric KS0 is yellow acid reacts with KNO; above 200PC: (b) KsO (xi) (c) KHSO4 (d) KHSO The property exhibited by concentrated sulphuric acid when it is used to prepare hydrogen chloride gas from potassium chloride: (xii) (a) Dehydrating property (b) Drying property (c) Oxidizing property (d) Non-volatile acid property The hydrocarbon formed when sodium propanoate and soda lime areheatedtogether (a) Methane (b) Ethane (c) Ethene (d) Propane Turn Over T23 522 (Nii) The acid which does (a) 1:CO ( (b) HPO (e) SO4 not form acid salt by a bas (d)CHcOOH (Niv) The general formula (a) CH2n+2 (b) C.H2n () C,H2n-2 (d) C,H2n 6 (xv) ofhydrocarbons with single covalent bonas is The indicator which changes to pink colour in an alkaline solution is: (a) Blue Litmus (b) Methyl Orange (c) Red Litmus (d)Phenolphthalein Question 2 (i) Match the Column A with Column B: Column B Column A T23 522 5 (a) Sodium Chloride . has two shared pair of electrons (b) Methane 2. has (c) Hydrogen chloride gas 3. a greenhouse gas (d) Oxidation reaction (e) Water 4 high melting and boiling points has low melting and boiling points 5. Zn-2e Zn? 6. S+2e s2- (ii) ne tollowing sketch illustrates the Study the diagram and answer the process of conversion of Alumina to Aluminu [5] following: >X UTTT ELECTROLYTE >z (a) Name the constituent of the (6) Name the powdered electrolyte mixture vwhich has a substance X' mixture. (c) What is the (d) Write the reactions name respectively. (ii) of the sprinkled on taking place at the electrodes in the the surface of the 'Y' electrolyte (anode) and Z' (cathode) 5] -[oxidizing agents / reducing agents Non-polar covalent compounds are (good/ bad) conductors of Higher the pH value of a solution, the more [acidic/ alkaline] it is. (d) , soluble in (e) in it. brackets: heat and electricity. (c) divalent metal process? Fill in the blanks with the choices given (a) Metals are good (b) MIXTURE [Silver chloride excess of Ammonium Conversion of ethene hydrogenation] / Lead to chloride] is a white precipitate that is hydroxide solution. ethane is an example of . . [hydration / Ntate the term/proren i ( he eens releasend m the following n hen an t m in the pnseous state ccepta an elec tuon o an annm Tendeney t an element to fom hains of idetical atoms the pcess by n a n i e of which tmmonia is large on a manufactred seae A N of salt tomed by purtial replacement of hvdroxyl radicals witn nn aeu radieal (CTh the ratiw vt t masS certan a volme of gas to the same volunne o hydngen measurd under the same conditions of temperature and pressn (a) IS Give the srwtural tormula ot the tollowing organie compounds: 2-chlonbutane Methanal But-2-yne (b) Give the IUPAC name of the following organie compounds: H H H H OH H H-C-C-C-C-H C-C-0-H H H H H SECTION B (40 Marks) (Atempt any four questions from this Section.) Question 3 ) 2 of the following ecases: ldentify the cation in each (a) Ammonium hydroxide precipitate which does solution when added not dissolve in to eNcess Solution B gives of ammonium a white hydroxide solution (b) Sodium hydroxide solution which is insoluble in T23 522 when added to Solution C excess of sodium gives a white precipitate hy droNide solution. () Fill (a) in the blanks by choosing (u) (iv) from the brackets: answer During eleetroly sis, the compound eddish brnn fumes () the conect at the anode. 121 in its molten state liberates |Nuc7 P'bBr: he ion which could be discharged most readily during electrolysis is Arrange the tollowing as per the instruction given in the brackets (a) Al, K. Mg. Ca (b) N, Be. 0, C (increasing order of non-metallic character) (c) P. Si, F. Be (decreasing order of valence electrons) Complete (decreasing order of and halance the its reactivity) following equations: (a) NHaC1 +Ca(O): > (b) CuSO4 (c) Cu Conc. HNO, NUOH Question4 i) (ii) (ii) State a relevant reason lor the following: 21 (a) Hydrogen chloride gas cannot be dried over quick lime. (b) Ammonia gas is not collected over water. Identify the alloy in cach case from the given composition: (a) aluminium, magnesium, manganese, copper (b) iron, nickel, chromium, carbon 12 Solve the following numerical problem. Ethane burns in oxygen according to the chemical equation 2C2Ho+ 70; 4CO; +6H;0 If 80 ml of ethane is burnt in 300 ml of oxygen, find the composition of the resultant gaseous mixture when measured at room temperature. T23 522 Turn Over (iv) c toloWing questions are pertaining to the laboratory preparation of Ammonia gas from Magnesium nitride: (a) Write (b) Why (c) How do you identify the gas formed? a balanced chemical equation for its is this method preparation. seldom used? Question 5 ) Write (ii) one use of the (a) Bronze (b) Fuse metal 21 following alloys: [21 Draw the electron dot structure for the following: (a) Ammonium ion (b) A molecule of nitrogen [At. No.: N (ii) (iv) =7, H = 1] Give a balanced chemical equation for the following conversions with conditions: (a) Ethene from ethanol (b) Ethyne from calcium carbide (c) Monochloromethane from methane Study the following observations and name the (a) (a) a reddish brown gas is released. When few drops of dilute sulphuric acid is added to Salt R' and heated, a colourless gas is released which (c) turns moist lead acetate paper sivery black. When few drops of barium nitrate solution is added to the salt solution Q', a is insoluble in white precipitate is formed which T23 522 ofthe reactions When a crystalline solid 'P' is warmed with concentrated H;SO4 and copper turnings b) anions present in each HCI Question 6 Detine State: [21 (a) Electronegativity (b) Gay-Lussac's Law of combining volumes The Empirical formula of an organic compound is CHCh. 2] If its relative molecular mass is 168, what is its molecular formula? Wi. C At. (i) 12, H= 1, Cl 35.5| Choose the substances given in the box below to answer the following questions: Iron Magnesium sulphite Zinc Sodium sulphide Lead Ferric chloride Copper Ferrous sulphate (a) The metal that will not (b) The compound that will produce sulphur dioxide gas when reacted with dilute 3] produce hydrogen gas when reacted with dilute acids. HCI. The solution of this compound produces dirty green precipitate with NaOH. (c) (iv)State (a) one relevamt observation for each ofthe following: 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. Question 7 ) Name the following: (a) 2 Organic compounds with same molecular formula but different structural formula. b) Group of organic compounds where the successive members follow a regular structural pattern, successive compounds differ by a CH:' group. T23 522 9 Turn Over (1) Give (111) reason for the following (a) lonisation potential deereaCs down a group (b) lonic compounds do not conduct electricity in solid state Calculate (a)he percentage of phosphorus in the fertilizer super phosphate CalHPO4 correct to 1 decimal point IAt WI H-1,P-31,0-16, Ca 401 (b) (iv) Write the empirical formula of C.H Answer the following questions with reference to clectrorefining of copper (a) What is the anode made of? (b) What do you observe at the cathode? (c) Write the reaction 13 taking place at the cathode. Question8 i) (ii) (iii) Arrange the following according to the instructions in brackets: (a) C2H2. C3H6, CHa, C2H (In the increasing order of the molecular weizht) (b) Cu, Na', Zn, Ag' Differentiate between the follow ing pairs based on the criteria given in the hruckets: (a) Cane sugar and hydrated copper sulphate [using concentrated H:SO) b) Sulphuric acid and hydrochloric Convert the following 12 (The order of Preferential discharge at the cathode ) reactions into a acid using oxygen and platinum catalyst (a) Ammonia to nitric oxide (b) Sodium hydroxide (c) Ferrous sulphide to hydrogen sulphide using hydrochloric to sodium 12) [type of salts formed] balanced chemical equation: sulphate using sulphuric 10 1222 given acid. acid. 31 (iv) Choose the answer [CCl (a) A (b) An (c) A from the list which fits in the PbO, NaCIl, deseription: Cuo, compound which undergoes thermal dissociation. amphoteric oxide. compound which is a non-electrolyte. T23 522 11 3 NH.CI
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