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ASSOCIATION OF ORISSA ICSE SCHOOLS ICSE MODEL EXAMINATION - 2025 CHEMISTRY F.M: Time: 2hours. 80 Marks separately. Answers to this Paper must be written on the paper provided You will not be allowed to write during the first 15 minutes. the Ouestion Paper. This time is to be spent in reading the time allowed for writing the answers. The time given at the head of this Paper is Attempt any four questions from Section b. A is compulsory. Section are given in brackets |] marks for questions or parts of questions The intended SECTION A (Attempt Question Choose from questions this Section) [15] 1 answers the correct (Do not copy the question, to the questions write Which ofthe following anode: Hydrogen P. 0.anode: none only given options. only.) platinum is used as electrodes. are formed at anode and cathode? cathode: Oxygen cathode: Hydrogen P Q (b)only only R (c) P& Q (d) both A water, from the answers cathode: Hydrogen R. anode: Oxygen (a) the correct of acidified In Electrolysis (i ) all compound precipitate is P is taken in a test tube and a few drops of dilute observed. Which of the following is compound P? (a) FeCl; (b) FeCl, (c) BaCl (d) CuCl, (ii) The mass of 0.4 gram molecules of oxygen is: (a) 13.8 g (b) 12.8 g (c) g 14.8 (d) 11.8 g Page 1 (Atwt: 0=16) H,SO,is added to it. A white (iv) What happens (a) It to an atom when a proton (c) It loses an electron (d) It loses a Reason ionization the lonization (R): energy of Magnesium A and R are true and R (b) Both A and R are true but R (c) A is true but Ris false. false but is The structures (vi) R is in energy decreases Both (d) A a charge with +1? of proton (A): The Assertion (a) ion gains an electron (b) It gains (v) becomes an it is is more a period from the correct than left Sodium. to right. of A. explanation the correct not is explanation of A. true. offive hydrocarbons are show below. HH H H3oCH3 CH3 Hsc H H- - -o-H H H H CH; HH CH;-CH-CH,-CH; H He- -cH H H H How many isomers of pentane are (a) 1 (b) 2 (c) 3 there? (d) 4 (vii) The compound which is composed of all three coordinate: (a) Sodium chloride (b) Ammonia (c) Carbon tetrachloride (d) Ammonium chloride Page 2 kinds of bonds as ionic, covalent and (viii) The most (a) 1s (b) 14 (c) 16 reactive nonmetals is found in group: (d) 17 (ix) Sulphate which forms a milky excess of it. white precipitate (a) Calcium with sodium hydroxideand is suiphate (b) Ferrous sulphate (c) Zinc sulphate (d) Copper sulphate (x) (xi) Elements which belong to the (a) Carbon sameperiod. and Calcium (b) Sodium and Oxygen (c) Silicon and Sulphur (d) Beryllium and Magnesium Zinc oxide an amphoteric oxide. react with zinc oxide is: (a) Acids and bases (b) Acids only is The type of substances (c) Bases only (d) Neither acids and (xii) A compound with So the Element X (a) Argon bases the formula XF; has a relative is: molecularmass of 78. (b) Calcium (c) Neon (d) Potassium is a strong acid. Reason (R): A strong acid dissociates almost completely in (a) Both A and are true and R is the R correct explanation A and R are true but R is not the correct A is true but R is false. (d) A is false but R is true. (b) Both (c) Page 3 water. of explanation of A. Assertion (A): Carbonic acid A. (xii) insoluble in light. (xiv) Ethane reacts with a Which substances molecule of chlorine iin the presence of ultraviolet are produced in the reaction. H-H H-H 2. --H 3. H-CI 4. (b)2 &2 &3 (c) 3 &4 (d) 2 &4 (a) 1 (xv) A student the Mg test takes Mg, C, Cu and Zn in tubes (II) and (III) and dilute four different H,SO,to (l) Cu I II Page 4 test tubes. and He adds concentrated H;SO4 (IV). Zn IV to which two In and I (a) (b) II and (c) and IV Il the tubes test SO:gas is formed. I III (d) 1ll and IV Question 2 () Aqueous copper sulphate incomplete (a) apparatus Complete electrolyzed. is solution diagram by labelling the The shown. is anode and cathode adding the power supply and the connecting wires. (b) Name the type of electrodes (c) Write the reactions at: ( ) (1) Anode (2) Cathode Match the used. and following column A with column B. Column B Column A A (a) paper blue black. (b) A white solid on heating lodide a yellow with salt base Complete nitric oxide 2. Ammonium 3. Chlorine 4. electrolyte. derived from a weak anda strong acid. the following by choosing the (a) Concentrate sulphuric acid is used it is a (non/high) volatile (b) Quick lime is (c) Alkenes have (d) Dilute nitric acid chloride copper. (d) A non (e) A gives 1. residue. (c) An acid which gives (ii) moist starch substance that turns a drying agent correct (e) Ferric chloride is by 5. Liquid CCI4 6. Conc. Nitric acid answers from the bracket: the laboratory in preparation of HCl [S] gas, since acid. gas.(HCV for a general formula Al,0;cannot be reduced Lead carbonate NH,) (C,H2n+/C,Han) reducing ( formed by agent/ electrolysis) displacement/ Page 5 direct combination) reaction. The ldentify the following: ice like (C) Separation of ore and Method Tendency of an element to form (0) An solid on cooling. due to difference in density gangue ionic negative compound which dissociates OH ion other than chains particles. compounds (e) Weak organic (a)) Draw the structural diagram of identical atoms. a to vield positive ion other than ion and H a RISSA ion. change which colour with pH the solution. of P) of Pure acetic acid forms an (a) of (iv) VATION ICE PAP (v) (1) Ethanoic of the following compounds: acid (2) 2-Butanol n the (3) Methanal [2] the uring compounds. organic of the following ing t Give (b) IUPAC name tim (1) fou H-C=C sof H A (2) CH3 CH3 H H ror ive SECTION B (40 Marks) (Attempt Question () any four uestions) 3 [2) An salt insoluble PbSO, is from another prepared PbCO; salt 1: an acid In step 2:a Step salt is is added to the salt added to get insoluble PbCO. PbSO4. the acid added. (a) Name of lead sulphate to show the fomation equation the Write (b) by adding a suitable salt. (21 (ii) What (a) property is by the exhibited oxide Heated copper (b) Sodium carbonate is following converted liberates carbon to substances? underlined copper by dioxide Page 6 using gas by ammonia using dilute gas. Hydrochloric acid. X and Y belong? (a) To which period (b) Which element's electronegativity is high? Compare the atomic radius of X and Y. (c) (iv) From the of the list FeCl, the elements substances NaOH required to conc. HCI conc. Choose the pairs the same. (a) NaCI [31 below given Pb(NO;)2 P (3) 3. The element X is to the right of the Periodic Table with atomic number 9 and the element Y is to the left, with atomic number (iii) prepare H,S H,SO, Cu the salts (a) to (c) and write the balanced equationfor (b) CuSO. PbS (c) 4 Question (i) The complete combustion of 2C,H, + 70, 24cc of ethane (ii) (a) What (b) What is is is mixed > an alkane gives reaction nitrogen, (2] with 100cc of oxygen, and the mixture is the volume of unreacted oxygen left? the volume of carbon dioxide ignited. formed? Ammonia gas is manufactured during The carbon dioxide and water. 4CO, + 6H,0 is summarized in Haber's process. [21 the flow chart below. N, from the air liquid ammonia 450 C, 200 atm, catalyst 8 gas A,formed from Bosch Process unreacted gases (a) Name the gas How are the unreacted A. (b) gasseparated from liquid ammonia? Page 7 (ii l) Separation of ore and gangue the in ofAluminium extraction done by using conc. NaOH. is (a) Name the process used the aluminium concentrate to (b) Write the chemical formula of the aluminium (c) Name the (iv) ore. separated from the ore particles. impurities Give balanced equation for each of the (a) Catalytic ore. [3) following: of ammonia. oxidation (b) Action of calcium bisulphite (c)Laboratory preparation with dilute nitric acid. of ethene by dehydration. Question5 The main (i) Write the chemical equation (a) (b) (i ) stage in the manufacture of H;SO,is the oxidation State any two conditions to required the composition of the following State (a) show of from the conversion SO; to SO; gas. SO, to (2] SO,. same. for the (2] alloys. Duralumin Bronze (b [3] (iii) Ramu was given a salt He observed a brown into a salt Y by evaporation. pungent odour is Name: (a) The liberated, salt X solution solution and asked to add and precipitate, separates On adding which turns it Ca(OH); NH,OH by the to red litmus from a few drops to excess. The filtrate was converted filtration. salt Y gas Z a colourless with blue. X. (b)The salt formed from the filtrate Y. odour Z. (c) Thegas with pungentod 3] (iv) Given below simplest in column A is a schematic hydrocarbon. ldentify the parts diagram of the Laboratory preparation labelled as A,B and C with the from the column B. Column NaOH Column A B A+B 2. Page & NaOH +CaO 3 CH,COONa 4 CH,-CH,COONa 5. CH, 6. C,H, correct of the options Question6 (i) Magnesium oxide reacts with water to form a base, Magnesium hydroxide. (a) Define the term (2) base. (b) Write a (ii) Two chemical equation for the reaction between Magnesium oxide and water. chemical reactions of organic compounds and answer the following: Study the reactions Equation l: are given below, (2] + 4Cl, >CCL, + 4HCI CH, Il: CzH, + Cl; What should be the Equation 1. C,H,Clh for the reaction condition 2. Name (iii) A the type of reaction metal spoon State is in mentioned in the Equation 1? Equation lI. silver: [3) electrode. (b) The negative (c) The takesplace with electroplated what is used as: (a) The positive (iv) that electrode. electrolyte. (a) State the Modern Periodic Law. (b)Which of the following belong (31 to: Element A B Atomic number 2 10 (1) the (2) the ) Question 5 same period same group 7 Zinc sulphide, when heated in air reacts according to the (3] following equations: 2ZnS + 30, 2Zn0 + 2S0, Calculate: The weight of ZnO formed if 388g of ZnS is heated. The weight of ZnS required to produce 5.6 liters of SO at STP. (c) The number ofthe moles of O; reqired at the same time. [At Wt: Zn=65, S=32,0-16] (a) (b) Page 9 (i) Madhu has X,Y and solutions Which solution: Z with pH 3,7 and 14 respectively. (a) Will turn phenolphthaleinpink. (b) Will not have any effect on litmus paper. (c) Will turn methyl orange pink. (iii) A compound on gave the analysis C=54.54%, H-9.09% The molecular mass following percentagecomposition: and O=36.36%. of the compound is found to the compound. [AtWt. H-1, C=12, Question be 88. Determine the molecularformulaof O=16] 8 i) State the relevant reason (b) Methane (ii) Draw the [At chloride an is An a hard crystalline solid. fuel. dot diagram of the following: (21 no: H=1, 0=8,Mg-12,Cl=17] ion (b) Magnesium (iii) is excellent electron Hydronium (a) for the following: [2] (a) Magnesium chloride element P has four electrons in the outer most shell [3] of its most atom and combines with another element of shell its atom. The compound formed does not conduct (a) What is the nature of the chemical bond (b) Give the (c) What is electron the dot structure of its in the compound? molecule. name of the compound? Page 10 B having seven electrons in electricity. the outer The (iv) structures are given compounds of Five organic only Use the organic compounds once to answer (3] below: the following questions: (B) (A) H H-CEC-H t--I (D) (C) Br Br I H- --H H H Br Br (E) H- - -H (a) B can be prepared from (b) Write (c) D is the chemical E by reaction Give chemical equation for the Hydrolysis. to reaction. prepare A. organic compound prepared by Halogemation. Which of the above Page 11 is used to prepare D?
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