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KAPOL VIDYANIDHI INTERNATIONAL SCHOOL(ICSE) TEMPLE OF KNOWLEDGE 1-03-21 Third Terminal Examination CHEMISTRY STD:IX Dur: 1hr15min. Marks: 40 Answer to this paper must be written on the paper provided separately. You will not be allowed to write during the first 15 minutes. This time is to be spent in reading the Question paper. Time given at the head of this paper is the time allowed for writing the answers. Section I is compulsory. Attempt any four questions from Section II. The intended marks for questions or parts of questions are given in the bracket [] SECTION I (40 MARKS) Question 1: 40 Marks VIVA SECTION II (40 MARKS) (Attempt any four questions from this section) a] Question 2: Answer the following pertaining to laboratory preparation of hydrogen gas: 1. Name the reactants used. 2. Give balanced chemical equation for formation of hydrogen gas. 3. State one precautionary measure to be taken in laboratory during preparation of gas. 4. Convenient method of collection of gas. 5. Granulated zinc is preferred to metallic zinc in the preparation of gas using dilute acid. [5] [5] b] 1 a] Question 3: Answer the following pertaining to Gas Law: 1. Who gave P-V relationship? 2. Who gave V-T relationship? 3. What is absolute zero temperature? 4. The absolute temperature value corresponding to 35 C [4] b] A weather balloon has a volume of 175L when filled with hydrogen at a pressure [2] of 1 atm. Calculate the volume of the balloon when it rises to the height of 2000m ,where atmospheric pressure is 0.8 atm. Assume the temperature is constant. c] Fill in the blanks : 1. In a chemical reaction ,the sum of the masses of the reactant and the product remains unchanged this is ________________law 2. A group of atoms carrying a fixed charge on them is called ________ 3. Formula of sodium carbonate is ________and that of ammonium sulphate is _________. a] b] Question 4: Fill in the blanks : 1. Isotopes have same ______but different ________. 2. Helium and Aluminium have atomic number 2 and 13 respectively .Their valencies will be ________and _______respectively. 3. The electronic configuration of silicon is _________and that of sulphur is _____. Show diagrammatically the electron distribution in sodium atom and sodium ion 2 [4] [6] [4] a] b] Question 5: Find the percentage of nitrogen in urea NH2CONH2 [atomic weight :N=14 H=1 C=12 O=16 ] What information do you get from the figure about the atomic number , mass number and valency of atoms X Y copy the table [2] [8] Atom X Atomic No. Mass No. valency Metal /non-metal valency Metal /non-metal Atom Y Atomic No. Mass No. Question 6: a] Balance the following chemical equations: a. Fe + H2O Fe3O4 + H2 b. Ca + N2 Ca3N2 c. Zn + KOH K2ZnO2 + H2 [3] b] Answer the following: 1. A liquid hygroscopic substance. 2. The gas evolved when potassium nitrate is strongly heated. 3. One metal which exhibits variable valency. 4. Convert nitrogen to ammonia. 5. Give balanced equation for thermal decomposition of lead nitrate [5] c] Find the relative molecular mass of Cl35 Cl37 [2] 3 Question 7: a] Answer the following pertaining to industrial method of preparation of hydrogen gas: 1. Name the process. 2. Complete the table : Step I reaction : Production of water gas(write condition(s)) chemical reaction A] Step II reaction Reduction of steam to hydrogen(write the Chemical reaction B] condition(s)) [3] b] Give balanced equation for the following conversion: 1. MgCl2 A-----HCl----B FeCl2 [6] 2. ZnO C------H2O----D Fe3O4 3. KAlO2 E--------KOH----F K2ZnO2 c] Explain why is fused calcium chloride or conc. Sulphuric acid used in a desiccator. ALL THE BEST 4 [1] 5 6 7
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