Tallentex Class 10 Chemistry Practice Questions 2024-2025 PDF

(Academic Session: 2024 - 2025) TALLENTEX PRACTICE QUESTIONS CLASS 10 CHEMISTRY Your Hard Work Leads to Strong Foundation CHEMISTRY CLASS-X Practice q...

(Academic Session: 2024 - 2025) TALLENTEX PRACTICE QUESTIONS CLASS 10 CHEMISTRY Your Hard Work Leads to Strong Foundation CHEMISTRY CLASS-X Practice questions 1. The total number of molecules in 10 g of Calcium carbonate is (1) 6.02 × 1023 (2) 6.02 × 1024 (3) 6.02× 1025 (4) 6.02 × 1022 2. The comparison of the particles P,Q,R,S and T is given in the table Substance No. of Protons No. of Neutrons No. of electrons P 25 30 25 Q 13 13 13 R 13 14 13 S 9 10 9 T 9 10 10 Identify atoms, ions and isotopes. Atoms ions Is o t o p es (1) P,Q,R R,T S and T (2) R, T P,Q, S Q and R (3) P, Q, R, S T Q and R (4) Q, R P, T S and T 3. What weight of sodium contains the same number of atoms as those in 8 grams of oxygen atom ? (1) 10.5g (2) 13.5g (3) 11.5g (4) 14.2g  1  4. Plaster of Paris  CaSO 4. H2O  on mixing with water sets to form  2  1 1 (1) CaSO4.H2O (2) CaSO 4.1 H2O (3) CaSO4.2H2O (4) CaSO4.2 H 2O 2 2 5. The valency of which one of the following is different from the others? (1) Potassium ion (2) Barium ion (3) Lithium ion (4) Ammonium ion 6. The metal obtained by self reduction process is (1) Cu (2) Zn (3) Fe (4) Ag 7. Read the given statements and mark the correct option. Statement 1 : Bohr’s orbits are called stationary orbits. Statement 2 : Electrons remain stationary in these orbits for some time. (1) Both statements 1 and 2 are true and statement 2 is the correct explanation of statement 1. (2) Both statements 1 and 2 are true but statement 2 is not the correct explanation of statement 1. (3) Statement 1 is true and statement 2 is false. (4) Both statements 1 and 2 are false. 8. Which of the following are isobars? (a) 1H1, 1H2, 1H3 (b) 20Ca40, 18Ar40 (c) 6C12, 6C13, 6C14 (d) 1H3, 2He3 (1) (a) and (c) (2) (a) and (d) (3) (b) and (d) (4) (b) and (c) 9. When 42 g of white solid ‘X’ is heated, 11 g of a gas ‘P’ and 5 g of gas ‘Q’ are evolved leaving behind a solid residue ‘R’ of mass 26 g. ‘P’ is an acidic gas which turns lime water milky. ‘Q’ is a neutral gas which condenses into a liquid and turns anhydrous CuSO4 blue in colour. The aqueous solution of ‘R’ is alkaline to litmus and gives white precipitate ‘S’ with BaCl2 solution. Compounds ‘X’ and ‘R’ respectively are (1) Na2CO3 and NaHCO3 (2) NaHCO3 and Na2CO3 (3) K2S and K2SO3 (4) KHCO3 and K2CO3 1/18 CLASS-X CHEMISTRY 10. A hydrocarbon has 3 gram carbon per gram of hydrogen, hence its simplest formula will be (1) CH4 (2) C6H6 (3) C3H8 (4) CH2 11. The schematic atomic structures of three elements X, Y and Z are given as X Y Z Which of the following statements is/are incorrect? (I) Z can form ZCl3 and ZCl5. (II) Y can exist in triatomic form. (III) X and Y combine to form X3Y. (IV) X and Z combine to form X3Z. (V) X will gain one electron to form a stable compound. (VI) X and Y combine to form X2Y2,Z and Y combine to form Y3Z2. (1) I, II, IV, V (2) I, II, III, IV,V (3) I, III, IV, V, VI (4) I,II,V,VI 12. Which of the following is the formula of barium peroxide and barium oxide respectively ? (1) Ba2O, Ba2O2 (2) Ba2O2, Ba2O (3) BaO2, BaO (4) BaO3, BaO 13. How many litres of water has evaporated on concentrating 10 litres of H2SO4 such that its pH decreases from 6 to 5 ? (1) 9 (2) 7 (3) 5 (4) 10 14. Which one of the following contains the smallest number of molecules? (1) 8 g of methane (2) 0.75 mole of carbon dioxide (3) 4g of oxygen (4) 64 g of sulphur dioxide 15. A brief information about two atoms X and Y are given: X: Atomic number = 7, Mass number = 14 Y: Atomic number = 7, Mass number = 15 Which of the following is correct about these two atoms? (1) Electronic configuration of X is 2, 8, 4 while that of Y is 2, 8, 5. (2) Both X and Y contain 7 neutrons. (3) X has 2 electron shells while Y has 3 electron shells. (4) Both X and Y have 5 valence electrons. 16. Neutron was discovered by (1) Rutherford (2) Bohr (3) Chadwick (4) Goldstein 17. Which one of the following metal oxides shows both acidic and basic character ? (1) CuO (2) K2O (3) Na2O (4) Al2O3 18. Which of the following statements is INCORRECT in accordance with a balanced chemical equation ? (l) It represents the exact number of atoms and molecules taking part in a chemical reaction. (2) It does not tell anything about the speed of reaction. (3) It reveals if any reaction is explosive. (4) None of these. 19. Which of the following reaction is not a precipitation reaction ? (1) AgNO3  NaCl  AgCl  NaNO3 (2) Pb(NO3 )2  2KI  PbI 2  2KNO3 (3) FeCl3  3NH 4 OH  Fe(OH)3  3NH 4 Cl (4) 2KI  Cl 2  2KCl  I 2 2/18 CHEMISTRY CLASS-X 20. One molecule of an “ic” acid of a non-metal having 5 electrons in valence shell reacts with a molecule of base to form a salt “X.” The base corresponds to the metal with one electron in valence shell. If the salt so formed can react with the same base in 1 : 2 ratio, predict the formula of the salt “X”. (1) K2SO4 (2) Na2HPO4 (3) KH2PO4 (4) Na3PO4 21. Take about 1g CaCO3 in a test tube heat over a flame when a colourless gas comes out of reaction. Which type of reaction is this? (1) Decomposition reaction (2) Displacement reaction (3) Double displacement reaction (4) Combination reaction 22. An ionic compound of element 'X' and chlorine has the formula XCl2 having the molecular mass 95u. What is the molecular mass of oxide of the element 'X' ? (1) 56u (2) 40u (3) 64u (4) 80u 23. Which of the following statements about the electron is incorrect? (1) It is a negatively charged particle. (2) The mass of electron is equal to the mass of neutron. (3) It is a basic constituent of all atoms. (4) It is a constituent of cathode rays. 24. The chemical formulae of some substances are listed - (a) AlF3 (b) CO (c) CoO (d) NaHCO3 (e) Na2S (f) N2O5 (g) CaSO4 (h) CuSO3 Which of the following has polyatomic anion with name ending in ‘ate’ ? (1) (a), (b), (c) & (h) only (2) (a), (e), (f), (g) & (h) only (3) (d) & (g) only (4) All (a) to (h) 3/18 CLASS-X CHEMISTRY 25. Identify the incorrect match from the following. Turmeric Phenolphthalein Methyl orange (1) Lime water Reddish brown Colourless Pink (2) Sugar solution No change No change No change (3) Vinegar Yellow Colourless Red (4) Baking soda Reddish brown Pink Yellow 26. Below diagram is the arrangement of electrolytic cell. In the above electrolytic method, 'P' undergoes electrolysis and gives 'Q' and gases 'R' and ‘W’. ‘W’ when reacts with Nitrogen gas gives ‘S’. ‘S’ when reacts with ‘P’ alongwith CO2, forms ‘T’ and ‘U’ in solvay process. ‘R’ alongwith slaked lime is further used in the manufacturing of ‘V’ in Hasenclever’s plant. Identify P, Q, R, S, T, U and V. P Q R S T U V (1) NaHCO3 CO2 NH3 NaCl Na2CO3 NaHCO3 Ca(OH)2 (2) NaCl(aq.) NaOH Cl2 HNO3 NH4Cl Na2CO3 CaOCl2 (3) NaCl (aq.) NaOH Cl2 NH3 NH4Cl NaHCO3 CaOCl2 (4) NaOH Cl2 NaCl NH3 NaHCO3 NH4Cl Ca(OH)2 27. Three elements X, Y and Z contains 8, 16 and 17 protons respectively. The number of electrons when these elements will form their most stable anion will be respectively (1) 8, 16, 17 (2) 10, 18, 18 (3) 8, 18, 18 (4) 10, 16, 16 28. Which of the following statements is always correct in case of neutral atom? (1) An atom has equal number of electrons and protons. (2) An atom has equal number of protons and neutrons. (3) An atom has equal number of electrons and neutrons. (4) An atom has equal number of electrons, protons and neutrons. 4/18 CHEMISTRY CLASS-X 29. Namah, a student of class - 10th has prepared a flow chart for extraction of metals from their ores, but has left some gaps due to some confusion, which have been labelled as W, X, Y and Z. Identify W, X, Y and Z in the flow chart. W X Y Z (1) Roasting Calcination Electrolysis of molten ore Reduction to metal (2) Roasting Calcination Electrolysis of molten ore Oxidation of ore (3) Calcination Roasting Electrolysis of molten ore Reduction to metal (4) Calcination Roasting Electrolysis of molten ore Oxidation of ore 30. Arrange the following metals in the order of their decreasing reactivity. K, Fe, Cu, Zn, Ca, Mg, Ag (1) K > Ca > Zn > Mg > Cu > Ag > Fe (2) K > Zn > Mg > Cu > Ca > Fe > Ag (3) K > Mg > Ca > Zn > Fe > Cu > Ag (4) K > Ca > Mg > Zn > Fe > Cu > Ag 31. There are four mixtures (i), (ii), (iii) and (iv) containing i : Ammonium sulphate + Water ii : Ammonium nitrate + Water iii : Anhydrous Copper sulphate + Water iv : Glucose + Water Identify the correct option. (1) i - endothermic, ii - endothermic, iii - exothermic, iv - endothermic (2) i - endothermic, ii - endothermic, iii - exothermic, iv - exothermic (3) i - exothermic, ii - endothermic, iii - endothermic, iv - exothermic (4) i - endothermic, ii - exothermic, iii - exothermic, iv - endothermic 5/18 CLASS-X CHEMISTRY 32. Some elements and ions with their valencies are enlisted in the given table: Name (Valency) Name (Valency) (i) Oxygen (2) (vi) Sodium (2) (ii) Iodine (1) (vii) Helium (2) (iii) Argon (0) (viii) Chlorine (1) (iv) Magnesium (3) (ix) Potassium (1) (v) Carbon (4) (x) Aluminium (3) Select the incorrect match. (1) (iv), (v), (vii) and (ix) (2) (iv), (vi) and (vii) (3) (i), (viii), (ix) and (x) (4) (ii), (iii), (v) and (ix) 33. Which among the following pairs are having same number of electrons? (1) O2–, F– (2) Mg2+, Ar (3) P5+, S2– (4) Na, Al3+ 34. Carbon dioxide, made up of elements carbon and oxygen, contains 27.2% by mass of carbon. What mass of oxygen will combine with 10g of carbon? (1) 26.7g (2) 3.74g (3) 7.28g (4) 4.28g 35. Pratyush took sulphur powder on a spatula and heated it. He collected the gas evolved by inverting a test tube over it as shown in fig. below. What will be the action of gas on (i) dry blue litmus paper ? (ii) moist blue litmus paper ? (1) Dry blue litmus paper would not show any change and moist blue litmus paper would not show any change. (2) Dry blue litmus paper would turn into red and moist blue litmus paper would turn into yellow. (3) Dry blue litmus paper would not show any change and moist blue litmus paper will change into red. (4) Dry blue litmus paper would not show any change and moist blue litmus paper will change into green. 6/18 CHEMISTRY CLASS-X 36. In the Solvay process, when CO2 is passed into brine with ammonia, then a product 'X' is produced. Thermal decomposition of this product 'X' will give 'Y' along with a gas and H2O. Then the product 'Y' is - (1) Na 2CO3 (2) NaHCO3 (3) NH4Cl (4) NaOH 37. Approximate pH values of a few solutions are given : Solution I : 2.2 – 2.4 Solution II : 6.8 Solution III : 7.4 Solution IV : 10 Solutions I, II, III and IV could be respectively (1) Vinegar, Hydrochloric acid, Window cleaner and Milk (2) Curd, Sodium hydroxide, Milk of magnesia and Coffee (3) Lemon juice, Milk, Human blood and Milk of magnesia (4) Antacid, Milk, Window cleaner, Glucose solution 38. Consider the following salts:- (i) NaF (ii) NaClO4 (iii) NaHSO4 Which of them when dissolved in water would form a basic solution? (1) (i) only (2) (ii) & (iii) only (3) (iii) only (4) (i) & (iii) only 39. The two atoms having the same number of neutrons are considered as isotones. The below given pairs are the exact example of isotones. Determine the number of protons, neutrons and electrons present in them: a) Potassium and Calcium b) Tritium and Helium Atom p e– n Atom p e– n K 19 19 20 K 19 19 20 Ca 20 20 20 Ca 20 20 20 (1) (2) H 1 1 1 H 1 1 2 He 2 2 2 He 2 2 2 Atom p e– n Atom p e– n K 20 19 19 K 19 20 19 Ca 40 20 40 Ca 20 20 20 (3) (4) H 1 1 0 H 2 1 2 He 2 2 2 He 2 2 1 40. Which of the following statements is correct? (1) The number of valence electron in sodium is 6. (2) The atoms 18X40 and 20Y40 represent a pair of isotopes. (3) Cl35 and Cl37 have same chemical properties. (4) Electronic configuration of Calcium is 2, 8, 10. 7/18 CLASS-X CHEMISTRY 41. Refer to the given figure and answer the following question: Test tube A Test tube B Oil Cotton wool Boiled distilled Anhydrous water calcium Clean iron nail chloride Clean iron nail Test tube C Test tube D Boiled distilled Sodium water chloride solution Clean iron nail Clean iron nail Rusting of iron nail is taking place in which of the following test tubes? (1) A and C (2) B and C (3) A and D (4) C and D 42. What will be the value of a, b, c and d respectively in the following equation? a C2H4O2 + b Fe c Fe(C2H3O2)3 + d H2 (1) 6,3,3,2 (2) 6,2,3,1 (3) 6,2,2,2 (4) 6,2,2,3 43. Look at the experiment carried out by a student in two stages : Absorption/Guard tube CuSO4 Residue from Green stage I Vitriol Bunsen Spirit lamp burner for for strong heating slow heating Stage I Stage II 8/18 CHEMISTRY CLASS-X Stage - I : (i) What will happen to anhydrous copper sulphate ? (ii) What will be left behind in the test tube ? Stage - II : (i) Which gas/gases will be evolved ? (ii) What will be the smell of the gas/gases ? (iii) What will be the colour and formula of the residue left behind ? Choose the correct option in Stage - I and Stage - II Stage - I Stage - II (1) (i) No change. (i) Only SO3 gas would be evolved. (ii) FeSO4 will change into (ii) No change in smell. green. (iii) Colourless residue, FeSO4 (2) (i) White anhydrous (i) A mixture of SO2 and SO3 CuSO4 will change to gases will be evolved. blue hydrated CuSO4.5H2O (ii) Anhydrous FeSO4 will (ii) Smell like that of burning be left behind in the matchstick. test tube. (iii) Reddish brown residue will be left behind, Fe2O3 (3) (i) No change. (i) SO2 gas would be evolved. (ii) FeSO4 will change into (ii) Pungent smell. black. (iii) Reddish yellow will be left, FeO. (4) (i) Change into black (i) No change. copper oxide. (ii) FeSO4 will change into (ii) No change in smell. white. (iii) White residue, PbO. 44. Select the correct option in which the number of atoms are same as number of molecules contained in 32g of O2. (1) 16 g of O2 (2) 71 g of Cl 2 (3) 28 g of N2 (4) 2 g of H 2 45. 21 If 10 molecules are removed from 200 mg of CO2, then the number of moles of CO2 left are (1) 2.88 × 10–3 (2) 1.66 × 10–3 (3) 4.54 × 10–3 (4) 1.66 × 10–2 46. 14 R and 15 R are the symbol of two elements. They are 6 7 (1) Isotopes (2) Isotones (3) Isobars (4) Isoelectronic 9/18 CLASS-X CHEMISTRY 47. In a solution of pH = 5, more acid is added in order to reduce the pH = 2. The increase in hydrogen ion concentration is (1) 100 times (2) 1000 times (3) 3 times (4) 5 times 48. Study the following statements about dilute sulphuric acid. (i) A white precipitate is formed when aqueous barium chloride is added. (ii) The solution turns anhydrous copper(II) sulphate from white to blue. (iii) Addition of a Universal Indicator shows that the solution has a pH value of less than 7.0. (iv) The solution reacts with copper(II) oxide, forming a blue solution. Which of the following statements confirm the acidic nature of the dilute sulphuric acid ? (1) (i) and (ii) only (2) (i) and (iii) only (3) (i), (iii) and (iv) only (4) (iii) and (iv) only 49. Study the following statements (i) Calcination and roasting of ores are the steps of metallurgy. (ii) Calcination and roasting reduce the ore to metal. (iii) Alkali metals are extracted by electrolytic reduction. (iv) Alkali metals are easily reduced. Which of the following statements are correct ? (1) (i) & (iii) only (2) (ii) & (iv) only (3) (ii) & (iii) only (4) All are correct 50. Which of the following pairs of substances would produce a brown precipitate if their aqueous solutions were mixed? (1) CuSO4 & NaOH (2) Fe2(SO4)3 & KOH (3) AgNO3 & NaI (4) None of these 51. Among the following groups which represents the collection of isoelectronic species ? (1) NO+, C 2 2–, O2–, CO (2) N2, C22–, CO, NO (3) CO, NO+, CN–, C22– (4) NO, CN–, N2, O2 52. An element X has atomic number 9 and mass number 19. Its anion is represented by (1) X2– (2) X– (3) X2+ (4) X+ 53. The following reaction is used for the preparation of oxygen gas in the laboratory. Heat 2KClO3 (s)  2KCl(s)  3O2 (g) Which of the following statement about the reaction is correct ? (1) It is a decomposition reaction and endothermic in nature. (2) It is a combination reaction. (3) It is a decomposition and accompanied by release of heat. (4) It is a photochemical decomposition reaction and exothermic in nature. 54. Which of the following compound imparts red colour to the flame and decomposes on heating to give oxygen and a brown gas ? (1) CaCO 3 (2) Mg(NO3) 2 (3) MgCO3 (4) Ca(NO3) 2 55. The number of molecules in 5.65 g of ammonia is approximately x×1023. What is the value of x ? (1) 3 (2) 2 (3) 4 (4) 1 56. In a sample of haemoglobin 0.33% iron is present. The molecular weight of haemoglobin is 67200 u. Calculate the approximate number of atoms of iron present in haemoglobin ? (Fe = 56 u) (1) 6 (2) 1 (3) 4 (4) 2 10/18 CHEMISTRY CLASS-X 57. How many total protons are found in one molecule of retinol (C20H30O) ? (1) 51 (2) 151 (3) 600 (4) 158 58. When the solution of a base is diluted what will be the change in pH of the solution? (1) pH of the solution remains the same (2) pH of the solution will increase (3) pH of the solution will decrease (4) pH of the solution climbs to 7 59. Acetic acid was added to a solid X kept in a test tube. A colourless and odourless gas Y was evolved. The gas was passed through lime water which turned milky. It was concluded that (1) Solid X is sodium hydroxide and the gas Y is CO2. (2) Solid X is sodium carbonate and the gas Y is CO2. (3) Solid X is sodium acetate and the gas Y is CO2. (4) Solid X is sodium hydrogen carbonate and the gas Y is SO2. 60. The compound which aqueous solution will have the lowest pH is (1) NaHCO3 (2) NH4Cl (3) Na2CO 3 (4) NaCl 61. Assertion : Magnesium is extracted from its ore by electrolytic reduction. Reason : All metals are extracted by electrolytic reduction. (1) Both assertion and reason are correct and reason is the correct explanation of the assertion (2) Both assertion and reason are correct , but reason is not the correct explanation of the assertion. (3) Assertion is correct, but reason is incorrect. (4) Assertion is incorrect, but reason is correct. 62. Observe the mixture given below. Powdered iron and copper (II) oxide On heating the mixture strongly taken in a crucible, (1) Formation of iron (II) oxide and copper takes place. (2) Formation of copper (III) oxide and iron (II) oxide takes place. (3) Formation of iron (III) oxide and copper (II) sulphate takes place. (4) No reaction takes place. 11/18 CLASS-X CHEMISTRY 63. The postulates of Bohr's atomic model are given below. Arrange them in the correct sequence. (a) As long as the electron revolves in a particular orbit, the electron does not lose its energy. Therefore, these orbits are called stationary orbits and the electrons are said to be in stationary energy states. (b) Electron revolve round the nucleus in specified circular path called orbits or shells. (c) The energy associated with a certain energy level increase with the increase of its distance from the nucleus. (d) An electron jumps from a lower energy level to a higher energy level by absorbing energy. But when it jumps from a higher to lower energy level, energy is emitted in the form of electromagnetic radiation. (e) Each orbit or shell is associated with a definite amount of energy. Hence these are also called energy levels and are designated as K, L, M, N respectively. (1) a c d e b (2) b c e a d (3) b e c a d (4) b a d c e 64. Which among the following are isobars? (1) bXa, bYa+1 (2) bXa, cYb (3) bXa, b+1Y a (4) bXa, b–1Y a–1 65. In a proper equation, which are the only numbers that can be altered ? (1) Molar masses (2) Superscripts (3) Coefficients (4) Subscripts 66. In general, nitrates are thermally unstable; when heated, the compounds break down. In which one of the following cases are the correct products given for the breakdown of the nitrate listed? Nitrate P rod uc t s (1) KNO 3 KNO2 + NO2 (2) Pb(NO3) 2 PbO + NO + O2 (3) HNO 3 NO2 + H2O + O2 (4) NH 4 NO 3 NH3 + N2O 67. Molecular mass of ammonia is 17u. The number of hydrogen atoms in 0.85 gm of ammonia (approximately) (1) 1× 10 22 (2) 3 × 10 22 (3) 6 × 10 22 (4) 9 × 10 22 68. Which of the following is not a reduction process? (1) Fe2+  Fe3+ + e– (2) Fe2+ + 2e–  Fe (3) Fe3+ + e–  Fe2+ (4) O2 + 4e–  2O2– 69. Silicon is a chemical element discovered by berzelius and it is present in sand as silicon dioxide. We know that the silicon atom contains 14 times more protons than hydrogen and that the number of electrons in its shell is equal to the number of neutrons. Which of the following statements is true about the particles in the atomic nucleus of silicon? (1) it has 28 nucleons (2) it has 28 neutrons (3) it has 28 electrons (4) it has 10 neutrons 70. Volume of gas at STP is 1.12 × 10–7 cc. Calculate the number of molecules in it. (1) 3.01 × 1020 (2) 3.01 × 1012 (3) 3.01 × 1023 (4) 3.01 × 1024 12/18 CHEMISTRY CLASS-X 71. Which of the following contains both Mg & Ca ? (1) Magnesite (2) Calamine (3) Carnallite (4) Dolomite 72. Which of the following is/are correct? (A) On heating, the pH of water increases. (B) Nature of solution is acidic when ammonium chloride is dissolved in water. (C) Turmeric changes from yellow to brown in acidic solution. (D) Ferrous sulphide and dil. H2SO4react and gives rotten egg smell gas. (1) A only (2) A and B (3) B and D (4) A, B, C and D 73. The pH of solution is increased from 3 to 6. Its H+ ion concentration will be :- (1) Reduced to half (2) Doubled (3) Reduced by 1000 times (4) Increased by 1000 times 74. Which of the following can undergo chemical reaction ? (1) MgSO4 + Fe (2) ZnSO4 + Fe (3) MgSO4 + Pb (4) CuSO4 + Fe 75. A metal object corrodes when it is exposed to the open air and humid weather. In iron, this change is called rusting in which flaky brown compound is formed. Which condition can cause severe rusting fast? (1) Submerged in boiled water with oiled layer. (2) Submerged in salt water. (3) Exposed in vacuum with moisture. (4) Exposed in air with calcium chloride. 76. The elements P,Q,R having given number of electrons in their respective outermost shells. Element P has 5 electrons in its L shell, element Q has 5 electrons in its M shell while element R has 7 electrons in its L shell. Which of the following statements is/are correct regarding elements P, Q and R ? (I) P and Q have valency equal to 3. (II) Atomic number of R and P are 7 and 9 respectively. (III) R has least atomic size among three elements. (IV) Element Q is stored in under Kerosene as it is highly reactive. (V) Element R has 3 more neutrons than element P (VI) Mass number of P is 28 and R is 18. (1) I, III, V, VI (2) I, II, III, V (3) I, III, IV, V (4) I, III, V 77. A thin sheet of gold foil is bombarded with -particles as in Rutherford’s experiment. Which of the given descriptions most accurately represents the path of -particles? No. of particles deflected No. of particles appeared to Undeflected by a small angle rebound I All None None II Most Most None III Most Some Very few IV A few Very few Some (1) I (2) II (3) III (4) IV 13/18 CLASS-X CHEMISTRY 78. Read the following statements & select the option that correctly fill the blanks. (i) The reaction in which one of the reactant carries the reduction of the product is known as______ (ii) Heating ore in the presence of excess of air is called______ (iii) Reduction of metal oxides by Aluminium is known as______ (iv) Heating ore in the absence of air is known as______ (i) (ii) (iii) (iv) (1) Heating Roasting Thermite Calcination process (2) Smelting Calcination Thermite Roasting process (3) Self Roasting Bayer’s Calcination Reduction process (4) Auto Roasting Aluminothermy Calcination Reduction 79. Which of the following is not redox reaction? (1) 2Mg + O2 2MgO (2) CaCO3 CaO + CO2 (3) H2 + Cl2 2HCl (4) Zn + H2SO4 ZnSO4 + H2 80. A compound 'X' on heating produces a colourless gas 'Y' and metal oxide 'Z'. The metal oxide is yellow when hot and show white colour when it is cooled. Identify X, Y & Z: (1) X = ZnCO3, Y = CO2, Z = ZnO (2) X = CaCO3, Y = CO2, Z = CaO (3) X = AgNO3, Y = NO2, Z = AgO (4) X = CuSO4, Y = SO2, Z = CuO 81. In the word "NICe", identify the symbols of the chemical elements. (1) nitrogen, iodine, caesium (2) nickel, caesium (3) nitrogen, caesium (4) nitrogen, iodine, cerium 82. In order to balance the chemical equation H2O2 + KMnO4 + HCl MnCl2 + KCl + H2O + O2 The stoichiometric coefficients are (1) 5,2,2,2,2,8,2 (2) 2,5,2,5,5,8,2 (3) 2,2,5,2,2,5,1 (4) 5,2,6,2,2,8,5 83. Description of a few atoms are given in the table. Atom P Q R S No. of protons 17 11 17 9 No. of neutrons 18 12 20 10 No. of electrons 17 10 17 10 14/18 CHEMISTRY CLASS-X Identify a cation, an anion and a pair of isotopes from the given table. Cation Anion Pair of isotopes (1) P Q P,Q (2) Q S P,R (3) R P R,S (4) Q S Q,S 84. One way to remove calcium deposit in kettles is to rinse them with vinegar. If 10 moles vinegar containing acetic acid, CH3COOH reacts with 20 moles calcium carbonate, CaCO3, then moles of Ca(CH3COO)2 produced is The equation for the chemical reaction is: CaCO3(s) + 2CH3COOH (aq) Ca(CH3COO)2 (aq) + CO2(g) + H2O(l) (1) 1 mole of Ca(CH3COO)2 (2) 20moles of Ca(CH3COO)2 (3) 5moles of Ca(CH3COO)2 (4) 10moles of Ca(CH3COO)2 85. The correct set of observations made on reaction of ferrous sulphate with aluminium is (1) Reddish brown solid & reddish brown fumes of SO2. (2) Reddish brown compound aluminium sulphate. (3) Reddish brown solid & evolution of SO2 and O2 gases. (4) A colourless solution and a black residue of an element. 86. Consider the following four equations  S2– + H O+ I. HS– + H2O  3  H S + OH– II. HS– + H2O  2  HNO + OH– III. NO3– + H2O  3  H CO + OH– IV. HCO3– + H2O  2 3 Water has an acid character in equation (1) I, II, III, IV (2) I, II, III (3) II, III, IV (4) I, II 87. P is produced by the action of chlorine on dry slaked lime. Q is a non-corrosive base and used for faster cooking. On heating R at 373 K, it becomes calcium sulphate hemihydrate. The P, Q and R respectively are (1) CaOCl2, NaHCO3, Gypsum (2) Gypsum, Na2CO3, CaOCl2 (3) Ca(OH)2, NaHCO3, Plaster of paris (4) CaOCl2, Na2CO3, NH4Cl 15/18 CLASS-X CHEMISTRY 88. Acids, Bases and Salts. A C I salt, Blue in colour has + HCl + NaOH + HCl + CH3COOH. water of crystallisation Release Release D Product consist H2gas H2 gas + B its aqueous acetate ions and a B is a salt of A. solution is cation of an element A resist corrosion. called brine. [G] which is the + E & F by principal cation products of extracellular fluid. (1) A-Zn, F-CO2, B-Na 2ZnO 2, C-NaOH. (2) A-Al, E-H2O, B-NaAlO2, G-K (3) A-Sn, C-Na 2CO3, I-CuSO4. 5H2O, D-NaOH (4) A-Sn, C-Na 2CO3, D-NaCl, G-Na 89. When a sample of copper containing iron as impurity is purified by electrolysis, the appropriate electrodes are : Cathode Anode (1) Pure iron Pure copper (2) Impure sample Pure copper (3) Impure iron Impure sample (4) Pure copper Impure sample 90. When a metal carbonate ‘X’ is heated strongly, it decomposes into metal oxide ‘Y’ and a gas ‘Z’.The metal oxide ‘Y’ is a major constituent of cement. Identify X, Y & Z respectively (1) CuCO3, CuO, CO2 (2) ZnCO3, ZnO, CO2 (3) CaCO3, CaO, CO2 (4) MgCO3 , MgO, CO2 91. There are three elements I, II and III. I : It is the largest among three elements with valency two. II : It has 1 more neutron than that of I. III : It has 2 shells and 4 valence electrons. By using the given hints. Identify elements, I, II and III respectively. (1) B, N,C (2) O, F, Ne (3) Be, B, C (4) Mg, B, C 92. A compound, AB2 has the following arrangement of electrons B A B The elements A and B are respectively. (1) F, O (2) S, O (3) Ar, O (4) Xe, F 16/18 CHEMISTRY CLASS-X 93. Metals are extracted from their ores by using different methods depending on their position in the activity series. Fill in the blanks in the given flow chart by choosing an appropriate option. Extraction of metal from its ore Metals of Metals of Metals of medium reactivity high reactivity low reactivity (v) Chalcocite of molten ore (i) (ii) can used as remedy heat in (viii) on insect bite excess of air (vi) At cathode Refining (iii) (iv) (vii) At anode Oxide of metal Reduction of metal Purification of metal (1) (i)-CaCO3, (iv) Calcination, (viii) Roasting, (vii) Positive ion (2) (ii)-Zns, (v) Electrolytic refining, (iii) Roasting (vi) Positive ion (3) (i)-ZnCO3, (iv) Roasting, (viii) Roasting (vi) Positive ion (4) (ii)-Cu2S, (iii) Calcination, (v) Electrolytic refining (vii) Negative ion 94. A student mixed two solutions X & Y. He recorded the following observations. (i) A white precipitate is formed. (ii) One of the product formed can undergo sublimation. The solution X & Y are respectively (1) AgNO3 (aq) and NaI (aq) (2) AlCl3(aq) and NH4OH(aq) (3) FeS(s) and H2SO4(aq) (4) CuSO4(aq) and NaOH(aq) 95. Oxide ‘M’ is a colourless gas. It reacts with oxygen to form a reddish-brown gas, Oxide ‘N’. Oxide ‘N’ is also formed by the decomposition of a compound ‘X’ along with the formation of a yellow residue ‘Y’. Which of the following statement is correct regarding to above information? (1) Oxide ‘M’ is PbO and oxide ‘N’ is PbO2. (2) In conversion of oxide ‘M’ to oxide ‘N’, oxide ‘M’ acts as oxidising agent. (3) In conversion of oxide ‘M’ to oxide ‘N’, oxide ‘M’ act as reducing agent. (4) Oxide ‘M’ is CO and oxide ‘N’ is CO2. 17/18 CLASS-X CHEMISTRY 96. Which of the following is the formula of the compound nickel bisulphate? (1) NiHSO4 (2) Ni2HSO4 (3) Ni2SO4 (4) Ni(HSO4)2 97. 10 g sample of a mixture of CaCl2 and NaCl is treated to precipitate all the calcium as CaCO3. This CaCO3 is heated to convert all the Ca to CaO and the final mass of CaO is 1.68 g. The percent by mass of CaCl2 in the original mixture is (1) 33.3 % (2) 16.2 % (3) 30 % (4) 11.0 % 98. The table below lists three characteristics of an atom of an element. Characteristics of an Element Number of Number of Number of Protons Neutrons Valence Electrons 37 48 1 An atom of which element is described by the data in the table? (1) Radon (Rn) (2) Cadmium (Cd) (3) Rubidium (Rb) (4) Astatine (At) 9 9. How many gram ions of SO4 are present in 1 gram molecule of K2SO4. Al2(SO4)3. 24H2O ? –2 (1) 2 (2) 3 (3) 1 (4) 4 1 0 0. An ore of potassium is (1) Bauxite (2) Dolomite (3) Carnallite (4) Cryolite Anskey 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 4 3 3 3 2 1 3 3 2 1 3 3 1 3 4 3 4 3 4 3 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 1 2 2 3 1 3 2 1 3 4 1 2 1 1 3 1 3 1 2 3 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 4 4 2 1 1 2 2 4 1 2 3 2 1 4 2 3 4 3 2 2 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 3 1 3 3 3 3 4 1 1 2 4 3 3 4 2 4 3 4 2 1 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 4 4 2 3 4 3 1 4 4 3 3 4 3 2 3 4 1 3 4 3 18/18