Formatting page ...
Hume McHenry Memorial High School Salisbury Park Pune 411037 Academic Year 2020 2021 Semester Examination Subject Chemistry Date: - 08/10/2020 Class: - X (A D) Marks : 80 SECTION I [40 Marks] [Attempt all questions from this section] Question 1 A] Choose the correct answer from the options given below: [5] 1] Electron affinity is maximum in a] alkali metals b] alkaline earth metals c] halogens d] inert gases 2] The electrode at which anions donate excess electrons and are oxidized to neutral atoms is the a] anode b] cathode c] electrolyte d] solution c] basic d] saline 3] Higher the pH value of a solution, the more a] alkaline b] acidic 4] As we descend the electrochemical series containing cations, the tendency of the cations to get reduced at the cathode a] increases b] decreases c] remains same d] changes c] 4 d] 2 5] The basicity of acetic acid is a] 3 b] 1 B] Write balanced chemical equations for each of the following [5] 1] Action of dilute sulphuric acid on Iron 2] Action of dilute hydrochloric acid on calcium carbonate 3] Reaction between copper oxide and dilute sulphuric acid 4] Reaction between sodium hydroxide and carbon dioxide 5] When sodium hydroxide is warmed with ammonium chloride C] State any one observation for each of the following [5] 1] Aqueous ammonium hydroxide is added to aqueous copper sulphate solution 2] Copper sulphate solution is electrolysed using platinum electrode Page | 1 3] When fused lead bromide is electrolysed using graphite electrodes 4] When caustic soda solution is added drop by drop to the solution of calcium nitrate 5] Action of ammonium hydroxide solution on iron sulphate solution D] Match the atomic number 2, 4,8,15 and 19 with each of the following [5] 1] A solid non metal belonging to the third period 2] A metal of valency 1 3] A gaseous element with valency 2 4] An element belonging to group 2 5] A rare gas E] Solve the following:- [5] 1] 0.583g of acetone when vaporized formed 225 cm of vapours at S.T.P. Calculate gram molecular mass of the gas [22.4 litres of any gas at STP =1 gram molecular mass of gas] 2] Calculate percentage of water of crystallization in washing soda. Na CO .10 H 0 [Na=23, C=12, O=16, H=1] F] Identify the terms [5] 1. The energy required to remove an electron from valence shell of a neutral isolated gaseous atom 2] A bond formed by shared pair of electrons with both electrons coming from the same atom 3] A substance that conducts electricity in molten state 4] Process in which a thin film of a metal gets deposited on another metallic article with the help of electricity 5] Elements which form positive ions by the loss of electrons G] Arrange the following as per instructions given in the brackets [5] i] Li, F, N [increasing order of electronegativity] ii] Na, Al, Cl [increasing order of ionization potential] iii] O , N , Cl [increasing order of number of covalent bonds] iv] Zn , Na , Cu [order of preference of discharge at the cathode] v] Br, F, Cl [decreasing order of atomic radius] H] i] Draw the structure of ammonia molecule [1] Page | 2 ii] Draw atomic or orbital structural diagram for the formation of [3] a] Sodium chloride b] Calcium oxide c] Magnesium chloride iii] Draw an electron dot diagram to show the formation of Methane molecule [1] SECTION II [40 Marks] Attempt any four questions from this section QUESTION 2 A] Show the formation of H O using the electron dot diagram. State types of bonds present in it [3] B] Write balanced equations for following: - [5] 1] CaSO + 2HCl 2] ZnS + H SO 3] KOH + CO 4] Fe(OH) +2HCl 5] Zn(OH) + NaOH C] State the type of bonding in the following molecules 1] Water [2] 2] Calcium oxide QUESTION -3 A] Study the table and answer the following questions:Atom [6] Atomic No A 11 B 17 i] Compare position of A and B in the periodic table. Ii] Which is more metallic? Mention electronic configuration iii] Write equation for the formation of ions A and B iv] What type of bod is formed between A and B Page | 3 v] Mention physical state and solubility in water for A and B B] Identify the compound used for the following:- [4] i] As an antacid ii] Manufacture of soap iii] Used to remove grease stains iv] Drying agent QUESTION -4 A] What do you understand by the following: i] Analysis ii] Reagent iii] Precipitation [4] iv] Amphoteric oxide B] Answer the following questions with respect to the electrolytic process in the extraction of aluminium [3] i] Identify the components of the electrolyte other than pure alumina and the role played by each. ii] Explain why powdered coke is sprinkled over the electrolytic mixture. C] Complete the following by selecting the correct option from the choices given: [3] i] The metal which does not react with water or dilute H SO but reacts with concentrated H SO4 is ______________________ [Al, Cu, Zn, and Fe] ii] The metal whose oxide which is amphoteric is reduced to metal by carbon reduction_________________________________ [Fe, Mg, Pb, Al] iii] The divalent metal whose oxide is reduced to metal by electrolysis of its fused salt is ___________________________________ [Al, Na, Mg, and K] QUESTION -5 A] The following is a sketch of an electrolytic cell used in the extraction of aluminum [4] Page | 4 i] What is the substance of which the electrodes A and B are made? ii] At which electrode A or B is the aluminium formed? iii] What are the two aluminium compounds in the electrolyte C? iv] Why is it necessary for electrode B to be continuously replaced? B] Distinguish between Electrovalent compounds and Covalent compounds [2] C] i] Empirical formula of a compound is XY . If its empirical formula weight is equal to its vapour density, calculate molecular formula of the compound. [2] ii] State the empirical formula of each compound whose molecular formula. [2] a] C H b] H O QUESTION 6 A] Complete the table given below:Nature of Anode [4] Nature of Cathode Ions Discharged at Cathode Anode 1] Electroplating an iron rod with silver 2] Electroplating a copper sheet with nickel 3] Electro refining of silver Page | 5 4] Extraction of Potassium from KCl B] Give appropriate scientific reasons: - [3] i] Zinc oxide can be reduced to zinc by using carbon monoxide but aluminium oxide cannot be reduced by reducing agent ii] The electrolysis of acidulated water is considered to be an example of catalysis. Iii] Although copper is a good conductor of electricity it is a non-electrolyte C] Mention the color changes observed when the following indicators are added to acids [3] 1] Alkaline phenolphthalein solution 2] Methyl orange solution 3] Neutral litmus solution QUESTION -7 A] In the activity series of metals-M is a metal above hydrogen in the activity series and its oxide has the formula M O. M O when dissolved in water forms the corresponding hydroxide which is a good conductor of electricity [3] 1] What kind of combination exists between M and O 2] State the no. of electrons in the outermost shell of M 3] Name the group to which M belongs. B] Give reasons [4] a] The oxidizing power of elements increases from left to right along a period. b] Noble gases are unreactive while atoms of elements other than noble gases are chemically reactive. c] Hydrogen chloride can be termed as a polar covalent compound d] Sulphuric acid is a dibasic acid C] Give one point of difference between the following pairs of term [3] 1] Mineral and Ore 2] Strong electrolyte and Weak electrolyte 3] Organic and inorganic acids ------------------------------------------------------------------------------------------------------------- Page | 6
|
