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Nersee Monjee Educatonal Trustr's M ontecusns JAMNABAI NARstE SaHOOL Narsee Monjee Bhaven, Nersee Manjee Muro. N.S Road No. 7. J.V.P.D. Scheme. Vile Pade (W). Mumbal 400 049, Indie c in 91 22 0915 7576 /8915 7570 www jns c in January 2024 Second Preliminary Examination CHEMISTRY Std. 10) Marks:80 Time:2 hrs Date:12/01/2024 paper provided separately. Answers to this Paper must be writtenon the the first 10 minutes. You will not be allowed to wrile during questionDTper the This time is to be spenf in reddlng allopeaior 9rinzthe answers. tme the is P per this head of the at given time The marks from Section B. Th ntended questions three and any A Section Attempt all questions from are given in brackets [/ for questions or parts of questions This paper consists of iprinted pages SE CTIONA Attempiallauesiton ronthissertion) Question 1 from the given options. Choose the correct answers to thequesticns copgithe question, write thecorrect answers only) (Do not |15] acetic acid evolves a gas. Which of the following (i) Sodium hydrogen carbonate when added to statements are true about the gas evolved? (A) It turns lime water imalky (B) It extinguishes a burning spinter (C) It dissolves in a solution of caisic soda (D) It has a pungent odour (a) A and B (b) A, B and C (c) B, C and D (d) A and D and pressure (ii) Assertion (A): Volumes of gases are converted to standard temperature conditions and compared. Reason(R): Changes in any volume changes the temperature and pressure. assertion. (a) Both assertion and reason are true, and reason is the correct explanation of 1 not thc ccorrect cxplanation of reason are truc, bul rcason is (b) Both assertion and falsc. (c) Asscrtion is tuc but reason is as ertum (d) Assertion is falsc, but rcason is truc. MgC0 are taken" Which one of them will b. (i) lfS moles cach of NaOL. H-0. CaCO1:and Ca-40, C=12, 0=l6, 1H=] hcaviest and lightest in mass? [At. wt: Na-23, Mg=24, Hcaviest Lightest MgCO) NaQH b c) CaCO) d)NaOH H0 MBCO3 CaCO (iv) 20 cm'of ethyne are reacted with S00 c of Oxygen Tie ciaion t ciie seaction is: 2CH) + 50: 4C0) + 2H,0 Calculate the total volume of gas remaining at the, end of the reaction. A!l volunes are measured at room temperature and pressure. (a) 400 cc (b) 520cc (c) 450cc (d) 490cc (v) Sulphunc aoai inits concentrated fom is used to prepare Nitric acid because: (a) it has two ionizabDhydrogen ions. (b) it yields nascent O2en on thermal decomposition. (c) it displaces more volailbacids on heating wth their corresponding salts. (a) i: forns acid salts. (vi) Asalt solution when treated wiii aqueous ammonia foms no precipitate and the gas formed on strongly heaimg this salt liberates violet vapours when passed Potassium iodide solution. Identif tie salt. through (a) Sodium nitrate (b) Potassium nitrate (c) Calcium nitrate (d) Ammonium nitrate (vii) Which one of the following compounds will form a red precipitate with ammoniacal cuprous chloride (a) CaHo (b) C;H12 (c) C1oH20 (d) CaHis (viii) A solution contains two cations namely Barium and silver, but one anion, which lest will be positive for that anion? (a) turns starch iodide paper blue black. (b) bums with a greenish yellow Mlame. (c) turns polassium iodide paper browm (d) turns Nessler's rcagent brown (ix) The reactions of four diflerent oxides P. 0, R, S are given. Preacts with Hydroehlorie acid but not with Sodium hydroxide Qreacts with both Hydrochloric and Sodium hydroxide Rdoes not react with both Hydrochloric and Sodiun iydroxid Sreacts with Sodium hydroxide but not with hydochloric acid Which row shows the correct typc of oxide? basic (a) R (b) P neutral acidic amnhoene R S R (C) (d) (x) The diagram shows elegtr lgsisof the given electrolytes using inert eluctodes, at which electrode is hydrogen gas produced? electrode 1 electrode 2 elecrode 3 concenrated conoantrted aqueous bydrochloric add s0dum chioride -elecuode 4 (a) only 1 (b) l and 3 (c) only 2 (d) 2 and 4 (xi) The substance which will NOT react with liquor ammonia: (a) Rock salt (b) Blue vitrio! (c) Slaked lime (d) Green vitriol potential: reactions)" in dissoived lonization lhcse thunderslorm. air the inoccur incrcasing of caeh OxidiscdOxId1sed nmolccules reducedredhccd reactant aduring when ions dissociate the toreference isedreduced with oxidOxiiseddreduced the VO lohuppens 0; 2NO: + 2NO0: reacl2NO 0,ions +NO, what shoss conrect isedreduced Oxidoxiiscddrcduced 0, These NO ro4 hielh (Xn)N " a) c) () e into is following infornation: NOT II Column following the from code 2.2mol 3.3 mol I4.mol will table: clements periodic the Water ofmolecules 4 of H=1] wt.:12,016, [At. 16 I7 section 4 2 I5 Ar <ArMg <Mgcorrect a > 1 3shows 4 1 the C] Cl >Na 3 D :P Na Oxygen > < the 5.61ofOxygen C. A B Na<Mg diagram ofWhichMg > C|< 2 10 Na> ClAr>Ar< Choose ofCO x of 2 1 4 IColumn (xii) The g 6.023 g Codes (2)(b)(c) 96 (a) (b) (c) (d) (xiv) 88 (d) xv) A. B. D. two IR which between formed U Compoundand P water?(a) U and Q (b) (c) S and R (d) V and U Question () Complete the following by choosing the correct answers from the bracket: (a) Anios Mgrates tow ards the (positvc negativc) clectrode and gets (reduced oxidised) (b) 04 moles of gas 'X'will occupy a volume of 6L/8.96 I). ic) Conc. HCl when treated with red lead acts as a/ad (oxidising/reduc1ng) agent. (Bronze/Brass) (d) The alloy used for clectrical fittings and j corativa aruclesjsmtde of (e) Reaction of Manganese with very dilate Niric acid prounees (Oxyyelydrogen). ( ) Observe the given dingram for the process on ncentrated ore of Aluminium ar answer the question that follows: +ELtCTROLYTE NINURE (a) ldentify the process. (b) Name X' and Y (c) Name the compounds in the elcctrotic mixture other than the ore of Aluminium. (d) Write a reaction that may take place mbsence of 'X". (e) Write the reaction at Z. (lii) State whether the statement is true or false w.r.t the underlined word, rewrite the false (5 statement: (a) When an atom of an clement loses or gains electrons it undergoes ionization. (b) An element X placed to the right of element B, will be a better reducing agent. (c) The hydrolysis of Calcium carbide results in formation of Ethylenc. () Gay Lussac's lawexplains the relationship between the volume of agas and the number of moles at constant conditions of temperature and pressure. (e) Sulphur produces its own acid on treatment with Conc, Sulphuric acid. 5 compounds followngorganic of fomula stnuctural Chll:0 general formula is (iv) (a) Draw the whosc contan1ngtwo carbons DCarbon compound Dimethvlacctvlene 2)Poston somt of butan-1-oc acid 3) 2.3-dimethyl dot (b) Draw an clectron the anion diagram for fomation of molcculc. for (") Obscrve the sctup formed on splitting of answer the'questions that preparation of ammonia and Funed XALul Clclum chleride waler [2 follow NH, - Cardboard Tower (a) Name 'X' and th kali. balance chemical equation. (b) ldentify an error in thseup and justify youransver with a X and alkali. (c) Writea balanced chemicaleguntion for the pteparation ofAmmonia from (d) Write a balanced chemical equ:lionfor the combustion of ammonia. (e) State your observation for the reaction in the question 'd' above. SECTIONB (Attempl ny four questions) Question: ) Write balanced chemical reactions for the folowing: (a) Fomation of insoluble sulphate of a divalent amphoteric metal using two salt solutions Ethanol (b) Formation of Carbon dioxide from (c) Reaction of thc sulphide of a bivalent metal with a monobasic acid 3 G) Write the IUPAC names of the 12) following compounds. CHO (a) HC-CCH,CH-CHCHCH;-CH, CH, (b) --4 (5] (i) Observe the schematic diagram and answer the qucyions that follow: P+ Ouick lime R ClH,COOH Cih /uv light + NazCO, Aq KOH Ethane boll (u) NanePand . (b) Dilferentiste betwcenRurnd 'T with the helpoohenicaltest. (c) Naine the product formedtis is treated witacoholic KOI. (d) Which of thecompounds willinc a higher pll, Por R? Justify your answer. Question 4 (i) Sudents of grade 10 were given the folling substances and asked to use the most approprinte method to preparce the given Mlts: Copper, dilute Sulphurle acid, Sodium carbonate, Calelum chloride, Iron, Nitric acid, Calelum, Copper (11) oxide, Chlorinc, dllute Hydrochlorle acid, (mention the method used) Write balunced chcmical cquations for the preparation of the salts, mention the method used. (3 (u) Ferric chloride (b) Blue vitriol (c) Caleium carbonate 7 (31 following: (n) Give reasons for the method concentrated by a chemmcal is ore Bauxitc (a) group halogens decreases down the (b) The reactivity of (c) allows large amount Dilutc Hydrochloric acid througn of current to pass (4 does not exist in nature. sulphuricaofd, anhydrous for water, pure production of (u1) Duc to its aflinity it is used in but acid. sophuric production of activity can result in the Volcanic industrialy. various chemicals and thus is prepared (a) Name the process. moxide. of Iron pyite to om Sulph r fornoasting equation chemical (b) Write a balanced to sulphuric acid it is not dissolvecin water is an acid anhydride of (c) Though Sulphur trioxide prepare the acid. Explain why? preparesulphuric acid of desired for hydrolysis of Oleum to equation cheical balanced (d) Writea concentration. Question S Pand 'Q' and was asked to differentiate between i) Sam was given two bl e coloured salts them using certain reagents observed that an acidic gas 'G' Stepl) On adding dilute hydroehloric acid to 'Phe dichromate solution from orange to green, wherc as is evolved which turms acidited poassium no such gas is evolved by salt Q formed solution to the solution of "0' a pale blue was Step 2) On adding ammonium hydroxide which dissolves in excess ammoniu bydroxide to fom a deep inky blue solution. solution and conc. Sulphuric acid to solution of Step 3) On adding freshly prepared Iron)sulphate of two liquids. '0'a brown ring was observed at the junction the following questions: Based on the information given, answer the P" and 'Q'. (a) ldentify the anion present in hydroxide solution to solution of'0' (b) Write a chemical reaction for addition of Ammonium observation if salt 'Q is thermally decomposed. (c) State your (d) Wnte a balanced chemical reaction taking place in step '1. (e) What will you observe if "G' is passed throgh barium chloride solution. (i) Answer the following questions based on the given table: Group 17 16 Period D A E (a) Giving reasons: i) ldentify the element with greater reducing property in group 2 ii) Arrange elements of period 3 in order of decheasing ionization potential. of amolecule of'C:. (b) Drawa ncat electron dot diagram for the formation ammoniacontains hyofroxyaons. (iii) State any two observations to prove aqueous |2] Question 6 and its compounds. ( ) The following diagram shows a series of reactions with Zinc Zn (OH): ZnSO4 [3 Zn0 D (a) Name the reagents used for convesions "A' and 'D'. (b) Write balanced chemical equations for the conversion B and C. tat (ii) Calculate the mass of Calcium carbenate which on decomposition will evolve the volume of (31 Oxygen just sufficient to roast 9.7 gofZinc sulphide. [Zn-65; Ca-40; C=12; 0=16; S=32) N: 4 (ii) Calculate: |2] (a) Number of gram molecules (6) Volume of 6.4 gof Sulphur dioxide. [At. wt: S=32, O-16] 9 and B(CCl4) and added silver (iv) Sharon took two solulions A(NaCI) nitrate solution to both A 2 and B separately. (a) In which solution will she find a change and why? the other solution than the (b)Gving suitable reason expluin why there will be no observation in one statcd by you in a"? Question (0) Ram accidently spilt Conc. Sulphuric acid on a wo0den shelf. (a) What will he observe? () Write a balanced chemical reaction to gthibit the |3] propectyastowby ieaid in 'a' with ethanol. (c) Write a chemical test to identify the compound formed in "b'. (ii) Element A(2,8,7), and B.(2,8,8,2) combine to fom a parucle. 3 (a) Write the ionic equations for fommanon ofthe ions ofA andhB. (b) State your Observation when excess Sodium hydroxtde sohtion is added to the solution of the substan e tomed on combinationofA and B. (ii) You are provided vith solutions of hydochloric acid, sodium bydroxide, barium chloride (21 and lime water onily ih,addition, you havea Bunsen burmer, test tubes, bent tubes and dropper. Describe making columns how will you difefentiate between the following pairs of substances? (a) Aqueous sodium chloride and aGheous Sodium sulphate (b) Solid Sodium carbonate and solid odium nitrate (iv) (a) 448cc of an unknown gas at S.TPawejghs 0.73 g. Calculate the gram molecular mass of 12 the gas. Will this gas be soluble in water? (b) Aflask can hold3.65 g of Hydrogen or 29.20 g of gas 'X under similar conditions of temperature and pressure. Calculate the relative molecular mass of gas X. Give a chemical test for this gas. 10 Question 8 i)Copper is usually mincd Irom coal, known as blister copper. It is about 98 to 99 per cent pure. 14) However, the electro-refining process can casily make it 99.95% pure, which makes it agood product to be used in electrical components. With reference to the given information observe the diagram and answer the following qucstions: D (a) What should be placed at Aand B? ) Name C and D. nogative electrode. (c) Write the reaction taking place at the positive and 31 () Wite balanced chemical reactonford Band C: (Use differegt substance for A, Band G) A Nitrogen Nitrogen Ammonia Nitrogen Zn-22.65%, S=11.15%, O=61.32% and (i) A compound has the following percentage composition fomula assuming that all H=4.88%. Its relative molecular mass is 37g. Calculate its molecular Oxygen as water of crystallization. the Hydrogen in the compound is present in combination with |31 [A.wt: Zn-65, S=32, O=16, H=1] 11
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