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SMT.SUNITIDEVISINGHANIA SCHOOL, THANE Class Subject Exam Date Marks 10th Chemistry Prelim 10.1.25 80 NAME: N e Time Sides 2hrs ROLL NO. STD/DIV: Instructions: Answer to this paper must be written on a paper provided separately You will not be allowed to write in the first 15 minutes. This time is to be spent reading the question paper. nfor o o T h , ane The time given at the head of this paper is the time allowed writing the l answers. Section Ais compulsory. Attempt any four questions from Section B. The intended marks for questions or partsof questions are given in brackets [1 SECTION-I(40 Marks) Attempt all questions from this Section Question 1 Choose one correct answer to the questions from the given options: [15] i) Which one of the following is not an alloy of copper a) Brass b) Bronze c) Solder d) Duralumin n g h yolecularweight of the compound a i) The Vapour density of agiven compound 'Xis 94..The n willbe: a) 188 b) 178 c) 180 d) 175 i) If the molecular fomula of an organte c mpound is CoHta it is: a) Alkane idevi b) Alkene c) Alkyne d) Nota hydrocarbgr iv) The atomic massesphsulphur (S), Oxygen (0) and Helium (He) are approximately 32,16 and 4 respectively. Whroh of the following statements are , regarding the number of atoms in 32 g of sulphu169 of oxygen and 4g of Helium is correct? P. 16g of oxyyen contains four times the number of atoms as 4 g of Helium. Q. 16g0 xygen contains half the number of atoms as 32 g of sulphur. b Dnly Q c) BothP and Q d) Neither P nor Q v) Which of the following reactions gives copper as a product? a) Passing dry ammonia over heated copper oxide. b) Adding dilute hydrochloric acid to copper oxide. c) Heating copper oxide. d) Combustion of copper nitrate. vi) The anhydride of sulphuric acid is: a) Basic oxide b) Neutral oxide c) Amphoteric oxide d) Sulphur trioxide vIn) The salt which in solution gives a dirty green ppt. with NaOH solution &a white ppt with barium chloride solution is: a) Iron (ll) sulphate b) Iron (1|) sulphate c) Iron (|I) chloride d) Iron (|l) chloride vii) Electron afinity is maximum in: a) Alkali metals b) Alkaline earth metals c) Halogens d) Inert gases ix) The compound formed when ethene reacts with hydrogen is: a) CH, h o o T lh , a n e b) CzH6 c) CsHs d) CaHo x) Hydracids are those acids which contain: a) Hydrogen and a metal b) Hydrogen,a non-metal and Oxygen Hydrogen and a non-metal other than Oxygen d) Hydrogen and Oxygen only xi) The statements below show the results when three metal _trips, R, Q, and R, are placed in blue copper sulphate solution. P- Solution turns green. Q- Solution becomes colourless. S i n g i r e g n l a R- Solution remains blue. Which of the following metals could be P, Q, a) P-Al, Q-Zn, R- Fe b) P-Zn, Q-Fe, R- Ag c) P-Fe, Q-Zn, R-Ag d) P- Zn, Q-Al, R-Fe xi) The organic compound mixed with ethanol to make it spurious is: a) b) c) d) Methanol Methanoic acid Methanal Ethanoic acid xii) Assertion (Ak AIkenes, alkynes and alkanes are examples of homologous series. ReasorR}} organic compounds of the homologous series have similar physical propertie: but different ch mical properties. a) Bol nd Rare true. b BohA and R are false. c) Ais true but R is false. d) Ais false but R is true. xiv) A -> A3+ B -> B-1 Number of electrons present in the outermost shells of atoms Aand B respectively are: a) 5,1 b) 3,1 c) 3,7 d) 5,7 xv)A compound which during electrolysis in its molten state, liberates a reddish brown gas at i anode: a) Lead [U] bromide b) Copper [lI] sulphate c) Copper [ll] oxide d) Sodium chloride Question 2 underlinedI i) Correctthe rewrite the correct statements: words in the following statements and (31 article with silver. electrolyte during electroplating of an as preferred is Nitrate Silver a) covalent bonds. has Three single silvery black. b) Nitrogen molecule moist lead acetate paper turns gas Oxygen c) (2] compounds: the following of reddish each a in present turnings, i) identify the anion X' is heated with conc. sulphuric acid and copper vapOurs from Kl solution a) When compound which liberates violet which turns lime evolved is gas brown 'Y, a gas is produced compound to added is acid orange to clear green. b) When dilute sulphuric KCr2O7 solution from water milky and turns acidified h i i) Match the following: a n Column B Column A a b C. d 64 g of Oxygen gas I mole of Oxygen gas Ostwald's process. i) Platinum i) Molybdenum i)Alcohol 44.8 Litres Haber's process. Esterification V) 6.23 x102Bmolecules [5] the brackets: the correct answers from choosing by following [CaO lconc. Sulphericacid] iv) Complete the by [alkene/alkyne] a) Ammonia is dried carbon-carbon tripl bond are called having compounds Organic b) [onl ionsonly molecules]. produces c) Astrongelectrolyte produces Cehenelpropene). d) Ethanol on dehydration ammonia acts as ammonia with opper oxfde, e) In the reaction of agentloxidizing agent]. folowing v) Draw the structures of the Jreducing (3] a) 1-Butanal b) 1,2 dichloroethane c) Pent-2-ene compounds: Give the IUPAC rtames ofthe following d) H- -- -H H H e) vi) Write balanced chemicalequation for the following: tetrachloride. a) Ethene is passed through bromine solution in Carbon acid. hydrochloric with reacts b) Calcium nitrate c) Ammonium hydroxide reacts with hydrochloric acid d) Action of water on calcium carbide. e) Action of ammonium hydroxide on ferric chloride. (5] SECTION -I| (40 Marks) Attempt any 4 questions from this section Question 3 i) State giving reasons if : a) Zinc and Aluminium can be distinguished by reacting the metal powder with conc. Sodium hydroxide solution? b) Iron (lD) chloride and Copper chloride solution can be distinguished using ammonium hydroxide solution. i) Draw the electron dot diagram for the formation of Hydronium ion. ii) A (2,7] and B [2,8,1] are two elements. Using this information complete the following is the nonmetallic element. a) b) Metal atoms tend to have maximum of electrons in the outermost shell. c) is an oxidizing agent. iv) Calculate the percentage of nitrogen and oxygen in ammonium nitrate. (NHNO3) [H=1, N=14, O=16]. (3) 31 [2] Question 4 i) Ravi heated 367.5 gof KCIO, in a test tube. The decomposition of potassium chlorate took place according to the equation. ( K=39, Cl =35.5, O = 16 ) 2KCIOa 2 KCI + 30, Find: (3] a) the volume of the colourless and odourless gas lihhaled during the experiment. b) the weight of the residue left behind in the testube. ii) A solution T of pH=7 was prepared.How wi he pH of the solution T change on addition of the following: a) Sulphuric acid b) A solution of a base. i) Aluminium carbide react_ with water according to the following equation: [4] 3CH4 Al4C + 12H20 4AI(OH)3 a) What mass of atsminiumhydroxide is formed from 12g of aluminum carbide? b) What voluae ofmethane at STP, is obtained from 12g of aluminum carbide? iv) An elemdgthasatomic number 16. To which group and period does it belong? [1 Questign i) Stai one relevant observation for the following reactions: [31 aj When excess aqueous ammonia is passed in Copper sulphate salt. b) Metallic Carbonate reacts with dil Sulphuric acid c) MnO2 reacts with Conc HCI. ii) Name the following: [31 a) a positive non-metallic radical which is basic in nature. b) the alkyl component of acetic acid. c) A metal present in cryolite other than sodium i) Draw the electron dot diagram for the following compounds.' a) Calcium oxide b) Ammonia molecule. [2 [2) iv) Explain the following a) Duralumin is used in the construction of aircrafts. b) The equation given below represents the molecule formation of element X. Fill in the box with the electron dot structure of the molecule. :X:+:X: Question 6 Q in a 0) Rahul takes a white coloured salt brown test tube. On heatina it produces reddish dissolved in on cooling it changes to white. Q is fumes and the salt turns yellow on heatina, sodium hydroxide and to the other part aCidimeo added [4] water. TOone part of the solution he ferrous sulphate solution was added. a) Name the salt Q. the solution. when Sodium hydroxide is added to b) Mention the colour of the ppt solution is added to it. when acidified ferrous sulbhate observation the Mention C) given salt. d) Mention the Basic radicle present in the ii) Solve occupied a) State the volume by 40 gm of methane at STP, [4] if its vapog density is 8. a out in the pufeform, forming carboxylic below 16.5 C crystallises structuraldragr m this cooling of on acid organic b) An Name and draw the crystalline mass resembling ice. acid. following: ii) Give reasons for the is the graphite anode electrolysis of molten Lead [laa omide, Why the to reference a) With preferred for this process? aluminium from pure Electrolysis process OExtraction of pure b) In the Hall's Hereoult's be oti nged regularly. alumina, the Graphite anodes needs to [3! alupinium.) of ore chief i) Bauxite is the above ore. used for toncentration of the a) Name the processchemic requation of the aluminium hydroxide to pure conversion for the balanced Writea b) Question 7 alumina. to c) Why is sodium hydxide added bauxite ore during the above process? process. key-with nickel to prevent rusting. For this i) Mr. Sam wants ta electroplate his a) Namethe'elctrolyte to be used (3j to be used b) Name the cathodeand anodeand anode. c) Giyethe reaction at Cathode and ii) Statethe difference between Calcination roasting. [1 iv) a) Draw the structure of the following organic 2-chloro, 3- methyl butane 2-bromo.4- methyl hexanoic acid i. compounds: [3) b) Write the IUPAC name: CHs HC-c-CH OH Question 8 An element X combines with oxygen to form an oxide XO,.This oxide is a good conductor of electricity and can be reduced to its metal only by electrolysis. a) Write the equation for the reaction formed when the oxide (X,0,.) combines with [3) hydrochloric acid. the outermost shell of X? b) Howmany valence electrons are present in reduction? c) Willelement X undergo oxidation or a) The description of an organic compound is as follows: Molecular formula is CsHg0. Functional group is attached to the first carbon atom. effervescence, releasing Reacts with sodium at room temperature with brisk hydrogen gas. Identify the compound and draw its structure. completely burn 90 dm3 of butane under similar b) What volume of oxygen is required to Thane conditions of temperature and pressure? 2CaH1o + 1302 8CO2 + 10H20 iii)Complete and balance the equations: a) CasN2 + H20 Schpol, b) C + HNOs(conc.) c) KHCO3 + H2SO4 (dil.) Singhania Sunitidevi S a t .
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