Tiêu đề 2 Acids, Bases and Salts - MCQs.pdf ✅

© www.bankofbiology.com 8921 510 476 1 2. ACIDS, BASES AND SALTS - MCQs 1. What causes sour and bitter tastes in food? a. Sugars and salts respectively b. Acids and bases respectively c. Proteins and fats respectively d. Vitamins and minerals respectively Answer: b) Acids and bases respectively 2. Which of the following is NOT a natural indicator? a. Litmus b. Red cabbage leaves c. Turmeric d. Methyl orange Answer: d) Methyl orange 3. From which organism is litmus solution extracted? a. Bacteria b. Algae c. Lichen d. Fungi Answer: c) Lichen 4. Colour of neutral litmus solution is a. Blue b. Red c. Purple d. Green Answer: c) Purple 5. What change does blue litmus undergo in the presence of an acid? a. Turns red b. Turns green c. Turns purple d. No change Answer: a) Turns red 6. What change does red litmus undergo in the presence of a base? a. Turns yellow b. Turns blue c. Turns purple d. No change Answer: b) Turns blue 7. What happens to a curry stain on a white cloth when rubbed with soap and then washed with water? a. Turns blue and stays blue b. Turns reddish-brown and stays reddish-brown c. Turns reddish-brown and then turns yellow again d. Turns yellow and then turns reddish-brown Answer: c) Turns reddish-brown and then turns yellow again 8. Which of the following is a synthetic indicator? a. Litmus b. Turmeric c. Phenolphthalein d. Red cabbage leaves Answer: c) Phenolphthalein 9. The indicator present in curry that reacts with soap is a. Litmus b. Red cabbage c. Turmeric d. Phenolphthalein Answer: c) Turmeric UNDERSTANDING THE CHEMICAL PROPERTIES OF ACIDS & BASES 10. Acids in red litmus solution will produce a. Blue colour b. Pinkish red c. Yellow colour d. No change in colour Answer: d) No change in colour 11. Acids in blue litmus solution will produce a. Red colour b. Pinkish red c. Yellow colour d. No change in colour Answer: a) Red colour 12. The change that occurs on addition of an acid to Phenolphthalein solution and Methyl orange solution respectively is a. Pinkish red, colourless b. Colourless, Pinkish red c. Yellow, colourless d. Colourless, yellow Answer: b) Colourless, Pinkish red 13. Bases in red litmus solution will produce a. Blue colour b. Pinkish red c. Yellow colour d. No change in colour Answer: a) Blue colour 14. Bases in blue litmus solution will produce a. Blue colour b. Pinkish red c. Yellow colour d. No change in colour Answer: d) No change in colour 15. Which of the following is an olfactory indicator? a) Litmus b) Clove oil c) Methyl orange d) Phenolphthalein Answer: b) Clove oil 16. The change that occurs on addition of a base to Phenolphthalein solution and Methyl orange solution respectively is a. Pinkish red, colourless b. Colourless, Pinkish red c. Remains yellow, Red to pink d. Red to pink, Remains yellow Answer: d) Red to pink, Remains yellow 17. What happens to the odour of onion when it is treated with NaOH? a. The odour intensifies b. The odour vanishes c. The odour remains unchanged d. The odour changes to a sweet smell Answer: b) The odour vanishes


© www.bankofbiology.com 8921 510 476 5 51. What acid and base react to form potassium sulphate (K2SO4)? a) H2SO4 and NaOH b) H2SO4 and KOH c) HCl and KOH d) HNO3 and KOH Answer: b) H2SO4 and KOH 52. What is the chemical formula for sodium carbonate? a) NaHCO3 b) Na2CO3 c) NaCl d) Na2SO4 Answer: b) Na2CO3 53. What type of solution will have a pH value greater than 7? a) Neutral solution b) Acidic solution c) Basic solution d) None of the above Answer: c) Basic solution 54. Which of the following salts is formed from the reaction of HCl and NaOH? a) Na2SO4 b) NaCl c) NaNO3 d) NaHCO3 Answer: b) NaCl 55. What is the pH of sodium acetate solution? a) Less than 7 b) 14 c) Greater than 7 d) 7 Answer: c) Greater than 7 56. What process is used to produce sodium hydroxide from brine? a) Dehydration b) Electrolysis c) Neutralization d) Recrystallization Answer: b) Electrolysis 57. What gas is produced at the cathode during the electrolysis of brine? a) Chlorine b) Hydrogen c) Oxygen d) Carbon dioxide Answer: b) Hydrogen 58. What is the chemical name of baking soda? a) Sodium carbonate b) Sodium hydrogencarbonate c) Sodium chloride d) Sodium sulfate Answer: b) Sodium hydrogencarbonate 59. What is the chemical formula of Plaster of Paris? a) CaSO4.2H2O b) CaSO4.1⁄2 H2O c) CaCO3 d) CaCl2 Answer: b) CaSO4.1⁄2 H2O 60. What is formed when Plaster of Paris is mixed with water? a) Calcium carbonate b) Gypsum c) Baking soda d) Washing soda Answer: b) Gypsum 61. What is the pH of a solution of sodium chloride? a) Less than 7 b) 7 c) Greater than 7 d) 14 Answer: b) 7 62. Which compound is used in soda-acid fire extinguishers? a. Sodium chloride b. Sodium carbonate c. Sodium hydrogencarbonate d. Sodium sulfate Answer: c) Sodium hydrogencarbonate 63. What is the use of chlorine gas produced during the electrolysis of brine? a) Fuel b) Disinfectants c) Cooking d) Fertilizer Answer: b) Disinfectants 64. Which salt is formed from the reaction of HNO3 and NaOH? a) NaCl b) Na2SO4 c) NaNO3 d) Na2CO3 Answer: c) NaNO3 65. Which of the following is a weak acid? a) HCl b) H2SO4 c) CH3COOH d) NaOH Answer: c) CH3COOH 66. What is the common use of bleaching powder? a) De-greasing metals b) Water treatment c) Fuel d) Fertilizer Answer: b) Water treatment 67. What is produced when NaHCO3 is heated for cooking? a) NaCl b) Na2CO3 c) CO2 d) NaOH Answer: c) CO2 68. Which of the following salts is basic in nature? a) Na2CO3 b) NaCl c) CuSO4 d) KCl Answer: a) Na2CO3