Tiêu đề NED Chemistry Marathon 2025.pdf ✅

18. Al+3 ion has A) 10 electrons B) 13 electrons C) 12 electrons D) 11 electrons 19. What is the colour of methyl Orange indicator A) Orange B) Orange red C) Yellow D) Red 20. What volume of 400 ml sample of gas at 760 torr occupy when the pressure is changed to 2 atm? A) 100 ml B) 869 ml C) 1520 ml D) 200 ml 21. Which one of the following food group provided maximum energy of the body per day? A) Carbohydrates B) Fats C) Proteins D) Vitamins 22. Which one is belongs to alkane family A) CH4 B) C2H6 C) C5H12 D) All of these 23. Co-ordinate covalent bond is present is A) HF+ B) H2S C) NaH D) NH+ 4 24. Significant figures of 807.30 is A) 5 B) 3 C) 2 D) 4 25. Line spectrum obtained from A) Atoms B) Ions C) Molecules D) All of these 26. NaHCO3 is also called: A) Baking soda B) Washing soda C) Caustic soda D) None of these 27. Alcohols are miscible in water because of ________________ A) H-bonding B) Dipole-Dipole force C) Covalent bonding D) Binding force 28. Addition of HCN with formaldehyde is an example of which reaction : A) Electrophilic addition B) Electrophilic substitution C) Nucleophilic addition D) Nucleophilic substitution 29. Organic compounds are soluble in all of these except A) Ester B) Benzene C) Petroleum D) Water 30. Reaction is said to be in equilibrium when _____________________ A) Conc. of reactant and product become equal. B) Rate of forward and rate of backward become equal. C) Temperature of opposing reaction become equal D) Opposing reaction become Happening 31. Greater the inter molecular forces : A) Lower the vapour pressure B) Greater the vapour pressure C) May be lower or greater vapour pressure D) none of these 32. Vitamin B2 is also called ________________ A) Thiamine B) Riboflavin C) Nicotinic acid D) Pyridoxine 33. Which of the following has greatest oxidizing nature . A)Cl2 B) Br2 C) I2 D) F2 34. Ligands are A) Electron pair acceptor B) Electron pair donor C) Neutral D) None of these 35. Which of the following has greatest tendency to lose electrons A) Li B) K C) F D) Cl
36. Covalent bond different in ___________ way A) It is unsaturated B) It is directional C) It is formed by mutual sharing D) All of these 37. A primary alkyl halide is the one which halogen is attached to carbon atom which is further attached to. A) Only one carbon atom B) More than one carbon atom C) One or no carbon atom D) none of these 38. The rate equation is R=K[A][B] if the concentration of both reactant become double the rate will be: A) Increase two times B) Increase Four times C) Remian Unchanged D) Increase three times 39. Which pair of elements show similar properties? A) Li and K B) Mg and Se C) Be and Na D) Cl and Sb 40.Interstitial hydrides called as A) Stoichiometric hydrides B) Metallic hydrides C) Border line hydrides D) Complex hydrides 41. Isopropyl alcohol is oxidized to form? A) Aldehyde B) Carboxylic acid C) Ketone D) Ester 42. Glass contain CuO give _____ colour A) Light blue B) Dark blue C) Green D) Red 43. Bayer’s method used in purification of bauxite ore when: A) Bauxite ore contain excess of SiO2 B) Bauxite ore contain excess of Fe2O3 C) Bauxite ore contain equal amount of SiO2 and Fe2O3 D) Bauxite ore only contain Fe2O3 44. Nitric acid in acidic medium shows the nature: A) Oxidizing agent B) Nitrating agent C) Reducing agent D) Acidic agent 45. Benzene show saturated nature due to A) Alternative double bonds B) Delocalized of pi-electron C) Cyclic structure D) Each Carbon attached only hydrogen 46. Ions, when an ionic compound is dissolved in water, can best be described as A) Hydrated molecules B) Hydrated ions C) Both a and b D) Neither hydrated ion and molecules 47. Water molecules undergoes_____________ chemical reaction A) Hydrolysis B) Hydration C) condensation D) Both a and b 48. Grignard’s reagent is active due to presence of: A) R-Mg B) Mg-X C) R-X D) Both a and b 49. Hydrogen produced in large scale on reaction with____________ A) Natural gas B) Ammonia C) Water D) All of these 50. Increasing __________ will increase the effective collision A) Temperature B) Concentration C) Exposed surface area D) All of these 51. Hydrogen is very good ___________ agent A) Oxidizing B) Reducing C) Both a and b D) None of these 52. Bonding common between NaOH and NH4OH A) Ionic B) Covalent C) Dative D) Both a and b