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GOLDCREST HIGH, LATUR 1ST TERM END EXAMINATION (2018-19) GRADE: 10 SUBJECT: SCIENCE PAPER-2 (CHEMISTRY) Time: 2 Hours Max. Marks: 80 Answer to this question must be written on the paper provided separately. You will not be allowed to write answers for the first 15 minutes. This time is to be spent on reading the question paper. The time given at the head of this paper is the time allotted for the writing the answer. The paper is divided into two sections. Attempt all questions from Section A and any four questions from Section B. The intended marks for questions or parts of questions are given in brackets [ ] SECTION-I (40 Marks) (Attempt all questions from this Section) Question-1 (a) Choose the most appropriate answer. (i) The nature of the oxide of the element in period 3 and Group IIIA A. Basic B. Acidic C. Amphoteric (ii) Which of the following forms an acidic solution in water: A CuSO4 B. Na2SO4 C. Na2CO3 [5] D. Neutral D. NaCl (iii) A salt which in solution gives a bluish white precipitate with NaOH solution and a white precipitate with BaCl2 solution is: A CuSO4 B. FeSO4 C. Fe2 (SO4 )3 D. Cu Cl2 (iv) Among the elements given below, the element with least electronegativity: A Lithium B. Carbon C. Boron (v) Bonding in this molecule can be understood to involve coordinate bonding: A.Carbon tetrachloride B.Hydrogen C.Hydrogen chloride D. Fluorine D.Ammonium Chloride (b) State one relevant observation for each of the following: (i)Lead nitrate solution is treated with sodium hydroxide solution dropwise till it is in excess. (ii)Anhydrous calcium chloride is exposed to air for some time. (iii)Lead nitrate solution is mixed with dilute hydrochloric acid and heated. (iv) Barium chloride solution is slowly added to sodium sulphate solution. (v)Water is added to the product formed when aluminium is burnt in a jar of nitrogen gas [5] (c) Write balanced chemical equations for each of the following: (i) Action of hot and concentrated Nitric acid on copper. (ii)Reaction of sodium hydroxide solution with iron (III) chloride (iii)Reduction of hot Copper(II) oxide to copper using ammonia gas. (iv)Reaction of zinc with potassium hydroxide solution. (v)Action of dilute hydrochloric acid on magnesium sulphite. [5] TEE-1/CHE/2018-19/KSH This question paper consists of 6 printed pages Page 1 (d) Give appropriate scientific reason for the following statements: (i) Ionic compounds are soluble in water. (ii) Inert gases do not form ions. (iii) Ionization potential increases across a period, from left to right. (iv) Alkali metals are good reducing agents. (v) Conductivity of dilute hydrochloric acid is greater than that of acetic acid. (e) (i) Some methods used for the laboratory preparation of Salts are A: Metal + acid B: Carbonate + acid C: Precipitation D: Direct combination Copy and complete the following table: Salt 1.Ammonium sulphate 2.Calcium carbonate 3.Iron (III) chloride 4.Lead nitrate 5.Zinc sulphate 6.Iron Sulphide [5] [3] E: Titration Method of Preparation (ii) What is meant by Ionization Potential? What is the relationship between ionization potential and the metallic/non-metallic properties of the element? [2] (f) Distinguish between the following with respect to the characteristic stated: [5] Distinguish Between Characteristic (i) Effervescence and Efflorescence Definition (ii) Sodium atom and Sodium ion Reaction with water (iii)Concentration and Strength of an acid Definition (iv) Electron affinity and Electronegativity Variation in groups and periods (v) Polar and Non-polar covalent compounds Type and nature of distribution of atoms (g) Identify P.Q.R.S.T in each case based on the information given below: [5] (i) A deliquescent salt P, turns yellow on dissolving in water and give a reddish brown precipitate with sodium hydroxide solution (ii) The white crystalline solid Q is soluble in water. It liberates a pungent smelling gas when heated with sodium hydroxide solution. (iii) A blue crystalline nitrate R which forms a black oxide on heating. (iv) A white colour soluble salt S which give gelatinous white precipitate with sodium hydroxide solution (v) An amphoteric oxide T, which is used for oxidation of ammonia. TEE-1/CHE/2018-19/KSH This question paper consists of 6 printed pages Page 2 (h) Some elements are given in the table below in their own symbols and position in the periodic table, while others (shaded) are shown with the letter. With reference to the table answer the following: Group No. 1 2 Li 13 14 15 D A Mg B C E Si F 16 17 18 O J Ne H K G [5] L (i)Which is the most electronegative element? (ii)How many valence electrons are present in G? (iii)Write the formula of compound formed between B and H? (iv)In the compound formed between F and J, what type of bond will be formed? (v)Draw the electron dot structure for the compound formed between C and K. SECTION-II (40 MARKS) (Attempt any four questions from this section) Question-2 (a) Give one test each to distinguish between the following pairs of chemicals: (i)Zinc nitrate solution and calcium nitrate solution. (ii)Sodium nitrate solutions and sodium chloride solutions (iii)Iron(III) chloride solutions and copper chloride solutions [3] (b) By drawing an electron dot diagram, show the lone pair effect leading to the formation of ammonium ion from ammonia gas and hydrogen ion. [1] (c) Give balanced chemical equations for each of the following: (i) Lab preparation of ammonia using ammonium salts (ii) Reaction of excess ammonia with chlorine (iii) Reaction of ammonia with sulphuric acid [3] (d) State what happens when (i) Ammonia gas is passed over oxygen in the presence of a catalyst.(ii) Ammonia gas is burnt in an atmosphere of oxygen in the absence of a catalyst. [2] (e) A solution of phosphoric acid was tested with universal indicator solution. The indicator changed colour to orange. What was the PH of the phosphoric acid solution? How would the PH Change when alkali is added to phosphoric acid solution. [1] TEE-1/CHE/2018-19/KSH This question paper consists of 6 printed pages Page 3 Question-3 (a) The diagram given below shows the preparation of nitric acid in the laboratory. Observe the diagram and answer the questions given below: (i) Identify A, B and C .Write a balanced reaction for the preparation of nitric acid. (ii) Why is concentrated sulphuric acid preferred over hydrochloric acid? (iii) How is nitric acid collected? (iv) What is the special feature of the apparatus? (v) What would happen if the temperature is increased above 2000 C [5] (b) How will you prepare the following? (i)Sodium chloride salt by neutralization-titration .(ii) Lead sulphate from lead nitrate (iii)Ferrous sulphate by simple displacement method. (iv) Barium sulphate by double decomposition reaction. (v)Sodium Sulphate from sodium carbonate. [5] Question-4 (a) The diagram gives the arrangement of the apparatus used for the preparation of alkaline gas. [4] (i) Identify X and Y. Explain why ammonium nitrate is not used in the preparation of this gas. (ii) Name the compound normally used as a drying agent during the process . (iii) How the gas is collected? (iv)Explain why it is not collected over water (v)In the laboratory preparation of this gas from ammonium chloride, the mouth of the flask in which the reaction is carried is kept slanting downwards. Why. (vi)The apparatus used for lab.preparation of this gas should be dry. Why? (vii)This gas is not dried using drying agents like conc.H2SO4, P2O5, and fused calcium chloride. Why ? TEE-1/CHE/2018-19/KSH This question paper consists of 6 printed pages Page 4 (b) Convert the following:(i)Lead oxide Lead nitrate Lead chloride. (ii) Lead carbonate Lead nitrate Lead Sulphate (iii)Lead carbonate lead nitrate Lead chloride (iv) Copper sulphate from Copper oxide. [4] (c) Give reasons for the following: (i)Conc.HNO3 acid is not used in place of conc.H2SO4 for the preparation of hydrogen chloride. (ii)Fumes are seen when a bottle of hydrochloric acid is opened. [2] Question-5 (a) Complete the table:NAME OF THE PROCESS OSTWALD S PROCESS HABER S PROCESS [2] INPUTS CATALYST TEMPERATURE PRESSURE OUTPUT PROMOTER(IF) CHEMICAL EQUATION (b) How will the action of dilute hydrochloric acid enable you to distinguish between the following: (i) Sodium carbonate and sodium sulphite (c) Define the following: (i) Deliquescent Substance [2] (ii) Lead nitrate and silver nitrate (ii) Hygroscopic Substance (iii) Desiccating Substance [3] (d) Identify the following A, B, C, D in each case based on the information given below. Sodium hydroxide solution is added to solution A. A white ppt is formed which is insoluble in excess sodium hydroxide solution. When ammonium hydroxide is added to solution B, a pale blue precipitate appears, this pale blue ppt disappears with excess of NH4OH is added to for form a inky blue solution. Solution C produces a dirty green ppt on addition of sodium hydroxide whereas solution D produces a yellowish brown ppt. [3] Question-6 (a) Elements A,B,C,D,E and F have the following atomic numbers: A-12. B-17, C-18, D-7, E-9, F-11. Answer the following with respect to the information provided above. [5] (i) Which one of them has the lowest electron affinity? (ii) Which one of them has the highest electron affinity? (iii) Which one of them has the largest atomic size.? (iv) Which one of them belongs to third period and has the highest ionisation potential.? (v) Draw an electron dot diagram to show the compound between A and B. TEE-1/CHE/2018-19/KSH This question paper consists of 6 printed pages Page 5 (b) Identify U,V,W,X,Y, in each case based on the information given below: [5] (i) The white crystalline solid U is soluble in water. It liberates a pungent smelling gas when heated with caustic soda solution. (ii) An element V which reacts with concentrated Nitric Acid to form sulphuric acid. (iii) A white crystalline salt W is warmed with calcium hydroxide solution. A gas is given off which turns moist red litmus paper blue. (iv)The nitrate X does not leave any residue on heating. (v) The action of heat on Y produces a reddish brown gas and a yellow residue which fuses with the glass of the test tube. Question-7 (a) [3] (b) ). State why: (i) pure nitric acid takes on a yellowish brown colour when exposed to light. How this colour can be removed? (ii)Why should the temperature of the reaction mixture of nitric acid not be allowed to rise above 200 degree Celsius? [2] (c) Conc .Nitric acid is strong oxidizing agent. How will you prove this. Show reactions with copper, carbon sulphur . [3] (d) Identify the following cations: Sodium hydroxide solution is added to solution A. A white ppt is formed which is insoluble in excess sodium hydroxide solution. When ammonium hydroxide is added to solution B, a pale blue precipitate appears, this pale blue ppt disappears with excess of NH4OH is added to for form a inky blue solution. Solution C produces a dirty green ppt on addition of sodium hydroxide whereas solution D produces a yellowish brown ppt. TEE-1/CHE/2018-19/KSH This question paper consists of 6 printed pages [2] Page 6
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