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VIBGYOR HIGH First Term Examination AY 2019-2020 CHEMISTRY Grade: IX Max. Mark: 80 Date : 16/09/2019 Time Allowed: 2 hour INSTRUCTIONS: Answers 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. The time given at the head of this paper is the time allowed for writing the answers. The intended marks for the questions or parts of questions are given alongside the questions. This question paper contains 6 pages. Section l (40 Marks) Attempt all questions from this section (a) i ii iii iv v (b) i ii iii Question 1 [40] Complete the following statements: [5] A symbol represents a short form of a/an_______. The _______ metals are placed in group II of the periodic table. The acidity or alkalinity of a solution is measured using _________. 1 dm3 of a gas is equal to ______ ml. _______ is a process used to convert vegetable oils into semisolid fat. [1] [1] [1] [1] [1] Answers the following in short: [5] State Boyle s law. How does temperature and pressure affect the solubility of gases? Mention any 2 methods by which a saturated solution can be converted into an unsaturated solution. [1] [1] [1] 1 iv v (c) What are greenhouse gases? Give two examples. Why are Group I elements known as alkali metals? Choose the correct answer: [1] [1] [10] 1 The salt whose solubility in water decreases with rise in temperature i ii iii iv Calcium sulphate Sodium nitrate Potassium nitrate Ammonium chloride 2 The maximum number of electrons which can be present in M-shell of an Atom i ii iii iv Two Thirty-two Eight Eighteen 3 MSO4 is a sulphate of a metal. What is the formula of its hydroxide? i ii iii iv MOH M(OH)2 MH MO 4 Dobereiner arranged elements according to the i ii iii iv Increasing order of atomic number. Decreasing order of atomic number. Increasing order of atomic weight. Decreasing order of atomic weight. 5 A deliquescent salt of a divalent metal i ii iii iv CuCl CaCl2 FeCl2 PbCl2 6 Set of metals with increasing order of reactivity i Al, Na, Ca [1] [1] [1] [1] [1] 2 [1] ii iii iv Cu, Hg, Ag Na, Zn, Ca Cu, Fe, Zn 7 The greenhouse gas which on combustion produces another greenhouse gas: i ii iii iv Nitrous oxide Ozone Methane Water vapour 8 Insoluble salts are prepared by i ii iii iv Synthesis reaction Neutralization reaction Precipitation reaction None of these 9 The relationship between atmosphere and mercury is that i ii iii iv 1 atmosphere = 76 mm of Hg 1 atmosphere = 76 cm of Hg 1 atmosphere = 760 cm of Hg 1 atmosphere = 760 dm of Hg [1] 10 A solution is said to be acidic when i ii iii iv (d) (e) It s pH is less than 7 It s pH is more than 7 It s pH is equal to 7 It s pH is between 5 to 8 [5] Copper pentahydrate is heated Copper sulphate and sodium hydroxide undergo double decomposition Reaction between nitrogen and hydrogen to form ammonia Dilute sulphuric acid is added to iron filings. Sodium chloride is added to lead nitrite solution. Match the following: i [1] [1] State your observation for the following reactions: i ii iii iv v [1] Rutherford [5] a. alkali metal 3 [1] ii iii iv v (f) (g) Natrium Goldstein Bromine Deliquescent alkali b. sodium hydroxide c. discovery of nucleus d. halogen e. discovery of protons [1] [1] [1] [1] Write the equations for the following reactions: [5] i ii iii iv v Silver nitrate silver + nitrogen dioxide + oxygen Ammonia + oxygen nitric oxide + water Barium chloride + sulphuric acid barium sulphate + hydrochloric acid Zinc suphide + oxygen zinc oxide + sulphur dioxide Potassium dichromate + sulphuric acid potassium sulphate +chromium Sulphate + water + oxygen [1] [1] [1] [1] [1] i Calculate the final volume of gas, if the pressure of the gas, originally at s.t.p is doubled and its temperature is tripled. [5] Section ll (40 Marks) Attempt any 4 questions from this section (a) i ii iii iv v (b) i ii iii iv v Question 2 [10] Give balanced equations for the following conversions. [5] Lead dioxide to lead monoxide Carbon dioxide to glucose Copper carbonate to copper oxide Magnesium to magnesium nitride Magnesium to magnesium chloride [1] [1] [1] [1] [1] Answer the following in short: [5] An element is represented as 40 20 . Name the shell which has valence electrons. Given 136 and 146 are the isotopes of carbon. Which isotope of carbon has maximum number of neutrons? Why is an atom electrically neutral? Plot a graph showing the relationship between pressure and volume of a gas. Convert 285o C into kelvin. [1] Question 3 (a) [1] [1] [1] [1] [10] Draw the orbit diagram as per the given instructions. 4 i ii iii (b) i (c) i ii [2] 100 cm3 of gas at 270C is cooled to 200C at constant pressure. Calculate the volume of gas at 200C . [2] Write balanced chemical equation for the reaction of hydrogen with [2] [1] [3] Nitrogen Chlorine Question 4 [10] Give reason for the following: [4] [2] ii Hydrogen is collected by the downward displacement of water and not of air, even though it is lighter than air. Volumes of gases are converted into s.t.p. conditions and then compared. I ii iii Differentiate between the following (any 2 points): Exothermic reaction and endothermic reaction Temporary hardness and permanent hardness Ionic bond and covalent bond [6] [2] [2] [2] Question 5 [10] When a neutral gas A which burns with a pop sound is passed through a boiling yellow non-metal B , it forms gas C . Identify B and C. Give balanced chemical equation for the reaction. Give the characteristic odour of gas C . Name the product formed when non-metal B reacts with oxygen. Name the oxidation product of gas A . [5] Name the following: [5] Longest period of periodic table. A hydrated crystalline salt green in colour. Horizontal rows of the periodic table. The law which states that, Pressure remaining constant, the volume of the given mass of the dry gas is directly proportional to it s absolute temperature. A gas which forms an explosive mixture with air. [1] [1] [1] [1] (a) I (b) (a) i ii iii iv v (b) i Ii iii iv v (a) Draw the orbit diagram for before and after combination in a molecule of methane. Draw orbit diagram for the structure of a molecule of ammonia. Draw atomic orbit structure for the formation of magnesium chloride. [2] [1] [1] [1] [1] [1] [1] Question 6 [10] Give balanced equation for the following reactions: [5] 5 i ii iii iv v (b) Sodium with cold water Zinc with an alkali Photochemical reaction using silver salt Thermal decomposition of ammonium chloride Oxidation of phosphorous [1] [1] [1] [1] [1] Urea is an important nitrogenous fertilizer with formula CON2H4. Calculate the percentage of carbon in urea. (C=12, O=16, N=14 and H=1) [5] Question 7 (a) Answer the questions based on the given figure. i ii iii iv v (b) i ii (c) i ii iii Name the process used to prepare water. What is the need of adding acid to water? Write the reaction for the laboratory preparation of Hydrogen. Name the reaction showing dissociation of water. How is hydrogen collected in the laboratory preparation?. [1] [1] [1] [1] [1] Define the following. [2] Supersaturated solution Isotopes [1] [1] Answer the questions based on the following reaction. [3] CuO + H2 Cu + H2O State the type of reaction. Name the oxidizing agent. Name the substance that undergoes reduction. [1] [1] [1] ***** 6
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