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I [I[e I BiiWI I r Date: 25 /01 /2024 /std: X I iI I I t I I INDIAN EDUCATION SOCIETY Orion (ICSE) ~w Secondary (2023-24) I Marks : 80 Preliminary Examination 1 I I Time : 2 Hours Subject: Chemistry Yo_ u ~ill not be allowed to write during the first 15 minutes. T . . This time is to be spent in reading the question paper_. . he time given at the head of this Paper is the time allowed for writing the answers ----------------------------------------- -------- ------Att~mpt all questions from Section I and any four questions from Section II. The intended marks for questions or parts of questions are given in brackets SECTION I (Attempt all questions.) Question 1: Choose the correct answers to the questions from the given options. (Do not t 15 copy the question, Write the correct answer only.) ) (i) The organic compound which when mixed with ethyl alcohol makes it spurious is: (a) Methanol (b) Methanoic acid (c) Methanal (d) Ethanoic acid Ethanol reacts with sodium to give , t (ii) (a) Sodium ethanoate (b) Sodium ethoxide (c) Sodium propanoate (d) Sodium methoxide The number of C-H bonds in propane molecule are(iii) (a) 6 l (b) 8 (c) 10 (d) 7 (iv) . The colour of universal indicator in water 1s: (a) Red (b) Blue Page 1 of 7 / (v) (vi) (vii) (viii) (ix) (c) (d) Green Yellow aration of nitric acid Concentrate sulphuric acid is used in the laboratory prep and hydrochloric acid because it 1s .. .. (a) Less volatile (b) Stronger {c) More volatile {d) Acts as a oxidizing agent . duction since; Fused alumina is reduced to aluminium by electrolytic re (a) Alumina is highly stable (b) Alumina is least stable (c) Alumina is not reduced by drying agents (d) Alumina is not reduced by reducing agents Assertion: Al, Zn and Pb are known as amphot~ric met~ls . alt and Reason (P) : These metals reacts only with dilute acids to give 5 . t water. Reason (Q): These metals reacts with dilute acids as well as w 1th ho concentrated alkali to give salt and hydrogen gas. Which of the above reasons are correct? (a) Only (P) (b) Both P and Q (c) OnlyQ (d) Neither P nor Q Addition reaction is a characteristics property of : (a) Saturated hydrocarbons (b) Unsaturated hydrocarbons containing double and triple bond (c) Methane (d) Butane A compound 'R' is heated in a test tube with concentrated sulphuric acid, glass rod dipped in ammonia solution when brought near the gas evolved produces dense white fumes. Which of the following could compound 'R' be? (a) (b) (c) (d) (x) (xi) Sodium carbonate Sodium chloride Sodium sulphite Zinc sulphide A compound 'X' consists of only molecules .Hence X will have : (a) A crystalline hard structure (b) Low melting point and a low boiling point (c) An ionic bond (d) A strong force of attraction between its molecules. The main components of bronze are : (a) (xii) Copper and Zinc (b) Copper and Tin (c) Copper and lead (d) Copper and Iron An acid which has three replaceable hydrogen ions: Page 2 of 7 (Xiii) (xiv) ~ (xv) (a) S I (b) Pu Ph uric acid (c) C hosphoric acid (d) arbonic acid Acetic acid An aqu . eous comp . (a) Sodium . hyd . ound which turns alkaline phenolphthalein colourless. . . roxIde (b) N itnc acid (c) (d) Sodium carbonate AThmmonium hydroxide e IUPAC n ame of ethyl acetylene is : (a) Ethyne (b) Propyn e (c) 1-Butyn e (d) 2-Bute ne (a) (b) (c) (d) Questi on 2. (i) Thel haci~ that S u P uric acidforms one normal salt and one acid salt is: Hydroc hloric acid Phosph oric acid Nitric acid Sfudy the}gu re given below and answer the questio ns that follow. [5] - ---- i i I L/1 , 1-- -11 lII 1111 i i Ii i ~ Name the liquid reactant 'A' and solid reactant 'C' Identify the substance 'B' also state its use. State the method of collection of the gas. Name the gas that is been prepared. What would you observe in each of the following cases? When excess sodium hydroxide is added to calcium nitrate solution. At the anode when an article is electroplated with a superior metal. Complete the following by choosing correct answers from the bracket. Ammonia gas is collected by the downward displacement of air because it is _ _ _ [ heavier than air/ lighter than air/ insoluble in water ] ~ --fb ) The alkaline behavior of liquor ammonia is due to the presence of __ ~ ions [ammonium I hydronium I hydroxyl] (c) The general formula for alkynes is _ _ .[ CnH2n / CnH2n-2 / CnH2n+2] Page 3 of 7 [2] [3] / r (iii) (a) Draw th 9 . mpounds: ( 1) 3 _p structural formula for th e following c0( ) Propanolc acid 3 . (b) Giv en tanol (2) 1, 1.2,2-tetrachloro ethane e th e IUPAC name of the following compou nd s. ( 1) (2) (5) Cl If H _ I ,-,=yT -" 11 - cl H (iv) 1. If Solder in electrical fuse. (c) stainless steel in surgical instruments. 1. (a) (b) I Cl [3] Magnalium in aircraft. (b) 2. 2. I-I state th e property of alloy which is useful for the mentioned application . (a) (v) H I cH 3 -C-CH3 Calculate the volume of oxygen required for the complete combustion of 8 -8 g of propane. [ C=12 ,H=1 ,0=16) C3H 6 + 502-+ 3C02 +4H20 M_aking use only of the substances given: Di!ute h~drochloric acid , Lead , dilute nitric acid , copper carbonate, lead (11) oxide. Give equations for the reactions by which you could obtain : Copper chloride . Lead nitrate Study the diagram given and answer the questions that follows : [2] [2] [3] Gla u retort \ ! k_, 1; / \ I \ i - f ~ . . {a) (b) ~~) Name the reactants 'A' and 'B' Identify the compound formed 'C' High temperatures are not used in the above method of preparation of compound 'C'. Give reason . SECTION B (Attempt any four questions from this Section.) Question 3 (i) Answer the following questions based on the Ostwald's process. Page4of7 [3] I (a) Te ~p~rature of the reaction taking place In _the ca_talytic chamber. (b ) Ox,datron of nitric oxide to nitrogen dioxide rs earned ou t at low . occurring in the (c) te_mperatures. Give suitable reason. Give a balanced chemical equation of the reaction absorption tower. (ii) . . . th Arrange the following as per the instructions given 1~ e brackets (a) Cl ,Si ,P ,Mg ,K ( Increasing order of electron affinity ) (b) C4H5 ,CJHa , C4H10 , C cular mass) 2 H4 ( Decreasing order of mo I0 (c) Br ,I .Cl ,F ( Increasing order of metallic chara cter) (iii) State the following : . mmon ia gas. (a) The drying agent used in the laboratory preparation _of~ of a diacid ic or (b) A salt formed by partial replacement of hydroxyl radrca s tria~idic base with an acid radical. n ammo nium (c) An ron which combines with polar covalent molecule to from a ion. . ated sodiu m (d) The product at the cathode during the electrolysis of conce ntr chloride solution. Question 4. [3] [4] [2] Draw the electron dot structure for the formation of follow ing comp ou nd5 (a) Ammo nia molecule (b) Calcium oxide (ii) State the observations for the following, when: [3] (a) Ammo nia gas is passed through Nessl er's reage nt in exces s . (b) Exces s of ammo nia reacts with chlorine gas. <'"'=-- k) " ') ------, .. \ - Conce ntrate d sulphuric acid is added to Sulph ur. (Ill Write balan ced chemi cal equat ions for the follow ing conve [3] rsions : ~ a) Sodiu m chloride from sodium sulphi te and dilute hydro chlori c acid. (b) Metha ne from methy l iodide. (c) Copp er (II) sulpahte from cop ,er and conce ntrate d sulph uric acid. (iv) Comp lete the statem ents given below with the corre ct word from the brack et. If 'N' is a non-m etal : [2] (a) Its ion N 1- will form a neutral atom at t h e - - ~ [Cath ode /Anod e] (i) (b) Ques tion 5. (i) (ii) (a) (b) (iii) Its valan ce shell will have _ _ _ (1/7/2) electr on/s. Moha n carrie d out the electr o-refin ing of coppe r. (1) State the obser vation at the anode : -= -{2) Give an ionic equat ion occur ring at the oxidiz ing electr ode. (3) Material of which anode is made up of: Write a balan ced chem ical equat ion for the prepa ration of ethan e from sodiu m propa noate . A comp ound 'Q' on dry heatin g gave a colou rless and slight ly acidic gas that had no effect on the acidif ied potas sium dichr omat e soluti on. The flame test of the comp ound 'Q' gave lilac flame . Name the comp ound 'Q'. Match the colum n 'A' with the colum n 'B' Page S of 7 [3] [1] [ 11 [5] 1', Colun,n 'A' Column 'B' ~hite precipitate Insoluble (1) Lead chloride in mineral acids. (b) White precipitate soluble in (2) Ferrous hydroxide hot water. (c) Curdy white precipitate in (3) Ferric hydroxide ammonia solution . (d) Dirty green precipitate (4) Lead sulphate ~e) Reddish brown precipitate (5) Silver chloride Q uestion 6. (i) Complete the following table which relates to s the homo Iogou series of oroanic comoounds shown below: I / Structural formula I o (a) 4 I IUPAC name of the second member of the series / Common Name (ii) II R-C- H I ~ R,,,.C'-OH [41 I I Ii i I I A hydrocarbon has the following percentage composition, Hydro gen 2 -2 (})/0 , [41 Carbon 26.6% and oxygen 71.2% . Calculate the empirical formul a of th e compound. If its molecular weight is 90. Find its molecular formul a. [H= 1 C=12 and 0=16] (iii) A gas cylinder contains 12 X 10 24 molecules of oxygen gas. If Avoga dro's [2 ] number is 6 X 10 23 Calculate (a) The mass of oxygen present in the cylinder. (b) The volume of oxygen at S.T.P. present in the cylinder. [0=16 ] Question 7. (i) ~ (ii) (iii) 1t (iv) Distinguish between the following pairs of compounds using the reagent (21 given within bracket: , (a) Sodium nitrate and sodium sulphite ( dilute sulphuric acid) (b) Dilute sulphuric acid and dilute hydrochloric acid (barium chlorid e solution) Oxygen oxidizes ethyne to carbon dioxide and water as shown by the [21 equation: 2C2H2 +502 --+ 4CO2 +2H2O What volum e of ethyne gas at S.T.P . is required to produce 8.4 dm 3 of carbo n dioxide? [H=1, C=12,O=16] Differe ntiate between the following pairs based on the criteria given in the [11 brack et. (b) Alumi nium hydroxide and sodium hydroxide ( Acidit y of a base) (c) Dilute hydro chlori c acid and acetic acid ( types of particles prese nt) (d) Gas libera ted by the reaction of dilute HCI on zinc metal and on calam ine . ( Natur e of the gas) pH of solutio ns W,X,Yand Z are 13,7,9,2 respectively answe r the following: l31 Page 6 of 7 r (a) Th 18 ules . . solution h' ( b) Thee sofutio basic gas. w !ch dissociates to give ions as well as r:11 ~ as ~ ~ hbera to chloride ammonium with (c) The Sol . n Wh!ch reacts 1d1 9 ut,on Which reacts with marble chips to liberate an ac c Question 8. (i) (41 1 Study the d'iagram and answer the questions based on 1 -1--- r - Gas 'B' lrOfl l!: hl rlCI \\',1n 11 " -..,~, Tap r'unntl - 4 ---tl-- Qucckli111 e I Mag11es1,un n,rnlk (c) (d) (ii) (a) (b) ~ "----------(c) ~ (iii) (a) #(iv) '---fb) ,; -::,:.a._. . the gas '8' collected in the Jar. Name 1 mentioned above of preparation the for used Why this method is seldom gas 'B'? Give a suitable reason. State how you will find out that the jar is full of a pungent gas. Give a balanced chemical equation for the above preparation method of gas 'B'. Name the substances underlined: Among the period 2 elements .lsthe element which has smallest size is: A non-polar diatomic molecule having triple covalent bond. The product obtained when excess of chlorine gas is treated with a basic gas. Correct the underlined words for the following statements and rewrite it. During electrolytic conduction there is transfer of molecules. Ammonia is used as a refrigerant since it has a high latent heat of evaporation. The formula of butanoic acid is CaH?COOH .What is its empirical formula? -----XXX----- Page 7 of 7 [3] [2] [1]
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