Std: 10 CHAPTER – 7 to 11 SCIENCE SEM – 1 & 2

CHEMISTRY PURVESH SIR (Ph): 9429976149

Q – 1 MCQ: 1. How many gram of NaCl is required to prepare 2 molar solutions? .............................................. (A) 117.0 gram (B) 175.5 gram (C) 171.0 gram (D) 117.5 gram 2. Choose the correct statement for basic aqueous solution ……................................ (A) pOH < 7 and pH > 7 (B) pOH > 7 and pH > 7 (C) pOH < 7 and pH < 7 (D) pOH > 7 and pH < 7 3. Find the correct option for the following statements: Statement – 1 : HCl turns blue litmus red and red litmus blue. Statement – 2 : NaOH turns red litmus blue and blue litmus red. (A) Statement – 1 is correct. (B) Statement – 2 is correct. (C) Both the statements are correct. (D) Both the statements are incorrect 4. Write pH range is the best for the growth and development of shrubs? .......................................... (A) 6.5 to 7.3 (B) 7.3 to 8.3 (C) 5.5 to 7.3 (D) 7.5 to 8.3 5. What will be the nature of salt when weak base reacts with strong acid? ............................... (A) Basic (B) Acidic (C) Neutral (D) Salty 6. What amount of solvent is required if 1 mole glucose gives 2 M concentration of solution. ....................................... (A) 500 ml (B) 1 litre (C) 2 litres (D) 250 ml 7. The Aldehyde group is ............................... (A) = CO (B) –OH (C) –COOH (D) –CHO 8. The general formula of alkenes is .................................... (A) CnH2n+2 (B) CnH2n (C) CnH2n-2 (D) CnHn 9. Which compound may have pH value 10? ............................. (A) HCl (B) H2O (C) Ca(OH)2 (D) CH3COOH 10. Brass is an alloy of ......................................... (A) Copper & Zinc (B) Copper & Aluminium (C) Copper & Magnesium (D) Copper & Tin 11. Which of the following is saturated hydrocarbon? ............................ (A) C4H10 (B) C2H4 (C) C2H2 (D) C3H5 12. Which of the following is an Alkyne? .............................................. (A) C6H6 (B) C6H12 (C) C6H10 (D) C6H14 13. The hydrocarbon with the general formula CnH2n+2 is an ....................................... (A) Alkane (B) Alkene (C) Alkyne (D) Unsaturated compound 14. Ethanoic acid is obtained by the _____________ of ethanol (A) Combustion (B) Oxidation (C) Reduction (D) Substitution 15. Which functional group is present in C3H7COOH? .................................... (A) Carboxylic (B) Alcohol (C) Ketone (D) Aldehyde 16. Formula of Ethene is .............................................. (A) C2H4 (B) C4H10 (C) C2H2 (D) C2H6

17. Saturated hydrocarbons are ........................................... (A) Alkanes (B) alkenes (C) Alkynes (D) all of these 18. Solder is an alloy of – .......................................... (A) Lead & Zinc (B) lead & Tin (C) Zn & Cu (D) Iron & Tin 19. Which metals can be cut with a knife? .................................................. (A) K & Na (B) Zn & Pb (C) Fe & Al (D) Hg & Cu 20. Galvanisation of iron means coating it with .............................................. (A) Zn (B) Ag (C) Pb (D) Sn 21. Roasting is generally done for enriching .................................................... (A) Carbonate ore (B) Sulphide ores (C) Silicate ore (D) Oxide ore 22. Which oxides show both acidic as well as basic nature? .............................................. (A) Metallic Oxide (B) non-metallic oxides (C) Amphoteric oxide (D) Neutral Oxides 23. The pH of 0.01 M NaOH solution is ................................................. (A) 9 (B) 11 (C) 12 (D) 14 24. Which of the following is a weak acid? ...................................... (A) CH3COOH (B) H2SO4 (C) HNO3 (D) HCl 25. pH of a salt formed by a strong acid and weak base is ............................... (A) more than 7 (B) less than 7 (C) equal to 0 (D) equal to 7 26. Acid present in bee sting? .............................................. (A) Methanoic acid (B) Hydrochloric acid (C) Acetic acid (D) Sulphuric acid 27. Which will turn blue litmus to red? ............................................ (A) HCl (B) Ca(OH)2 (C) NaCl (D) NaOH 28. Which of the following statements is correct about an aqueous solution of an acid and of a base? (i) Higher the pH, stronger the acid (ii) Higher the pH, weaker the acid (iii) Lower the pH, stronger the base (iv) Lower the pH, weaker the base (A) (i) and (iii) (B) (ii) and (iii) (C) (i) and (iv) (D) (ii) and (iv) 29. 500 ml aqueous solution is prepared by dissolving 2 moles of HCl in water. What will be the molarity of this solution? ...................................... (A) 1 (B) 2 (C) 3 (D) 4 30. Which formula is correct? ................................................ Mole = Molecular mass/Weight (B) Mole = Weight / Molecular mass Mole = Weight / Litre (D) Mole = Molecular mass / Litre 31. Which of the following solutions will have pH = 2? ...................................... (A) 0.01 M HCl (B) 0.02 M HCl (C) 0.01 M H2SO4 (D) 0.02 M H2SO4 32. What will be the pH of aqueous solution of NH4Cl? (A) pH = 7 (B) pH > 7 (C) pH < 7 (D) pH = 0 33. What will be OH– concentration in aqueous solution having pH = 8? ................................ (A) 1 x 10-8 M (B) 1 x 10-6 M (C) 8 x 10-6 M (D) 8 x 10-8 M

34. What type of substance is NH3? ........................................... (A) Strong acid (B) Weak acid (C) Strong base (D) Weak base 35. By which reaction metal is obtained from metal oxide? ................................................... (A) Liquefaction (B) Reduction (C) Calcination (D) Roasting 36. Which of the following substances is hygroscopic? ............................................ (A) Cryolite (B) Feldspar (C) Anhydrous calcium chloride (D) Slag 37. An aqueous solution is basic if [OH –] _____ . (A) = 10 –7 M (B) > 10 –7 M (C) < 10 –7 M (D) < 7

38. If [OH –] = 10 – 3 M, pH = __________________ . (A) 11 (B) 3 (C) – 11 (D) – 3 39. What can be pH of KNO3? ................................ (A) 11 (B) 2 (C) 7 (D) 9 40. If [H3O +] increases, what is the change in pH? ............................................. (A) increases (B) decreases (C) remains same (D) anything can happen 41. Concentration of sulphide ore is carried out by _______________ . (A) Centrifugation (B) Froth flotation (C) Magnetic separation (D) calcination 42. Metal + _______________ Metal oxide + Dihydrogen gas (A) dioxygen (B) water (C) other metal (D) acid 43. Which alloy is used to prepared scientific balance? ..................................... (A) Duralumin (B) Steel (C) Bronze (D) Magnelium 44. Which of the following non-metallic element possesses lustre? ................................. (A) Iodine (B) Sulphur (C) Phosphorus (D) Carbon 45. What is used as a catalyst in manufacture of Sulphuric acid by Contact process? ....................... (A) Al2O3 (B) K2O (C) V2O5 (D) Fe 46. Which of the following is not a neutral oxide? .......................................... (A) CO (B) N2O (C) H2O (D) SO2 47. What is the molecular formula of formalin?............................................ (A) HCOOH (B) HCOOCH3 (C) HCHO (D) HCOOC2H5 48. If one of the hydrogen atom of an alkane is displaced by hydroxyl group than which type of compound we get? .............................................. (A) Ketone (B) Ester (C) Alcohol (D) Aldehyde 49. Which solution will be basic? ...................................................................... (A) [H3O+] = 10–5 M (B) [H3O+] = 10–12 M (C) [H3O+] = 10–7 M (D) [H3O+] = 10–4 M 50. Which catalyst is used for the industrial production of Hydrogen? ......................... (A) Iron (B) Nickel (C) Vanadium pentoxide (D) Palladium

Section A (2 marks) 1. Mention the limitations of Arrhenius acid base theory. 2. Explain the importance of pH in digestion of food. 3. Define pH of solution. Mention limitations of pH scale. 4. Write two chemical properties of salt 5. Write a short not on coke 6. Physical properties and uses of ammonia gas OR Physical properties and uses of sulphur Section B (3 marks) 7. Uses of dihydrogen gas 8. Describe Frasch method of extraction of sulphur OR Preparation of ethyne in laboratory 9. Explain chemical reduction and electrochemical reduction OR Explain refining of copper by electrolysis 10. Explain the froth floatation process 11. Write properties of propanone. OR Properties of Methanal 12. Write short note on Allotropes of sulphur Section C (5 marks) 12. Discuss chemical properties of metals. 13. Preparation of ethene in laboratory. 14. Discuss the extraction of aluminium from bauxite

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