Chemestry 10th : ā§°āĻ¸āĻžāĻ¯āĻŧāĻ¨ āĻŦāĻŋāĻā§āĻāĻžāĻ¨ (āĻĻāĻļāĻŽ āĻļā§ā§°ā§āĻŖā§) â MCQ Set 1
Q1. What is the pH of a neutral solution ? āĻ¨āĻŋā§°āĻĒā§āĻā§āĻˇ āĻĻā§ā§°āĻžā§ąāĻŖā§° pH āĻŽāĻžāĻ¨ āĻāĻŋāĻŽāĻžāĻ¨ ?
Ans: The pH of a neutral solution is 7. āĻāĻ¤ā§āĻ¤ā§°: āĻ¨āĻŋā§°āĻĒā§āĻā§āĻˇ āĻĻā§ā§°āĻžā§ąāĻŖā§° pH āĻŽāĻžāĻ¨ ā§āĨ¤
Q2. Define Oxidation and Reduction. āĻ āĻā§āĻ¸āĻŋāĻĄā§āĻāĻ¨ āĻā§°ā§ ā§°āĻŋāĻĄāĻžāĻāĻāĻ¨ āĻ¸āĻāĻā§āĻāĻž āĻĻāĻŋāĻ¯āĻŧāĻžāĨ¤
Ans: 1. Oxidation: Gain of oxygen or loss of hydrogen. 2. Reduction: Loss of oxygen or gain of hydrogen.
āĻāĻ¤ā§āĻ¤ā§°: 1. āĻ āĻā§āĻ¸āĻŋāĻĄā§āĻāĻ¨: āĻ āĻā§āĻ¸āĻŋāĻā§āĻ¨ āĻ˛āĻžāĻ āĻā§°āĻž āĻŦāĻž āĻšāĻžāĻāĻĄā§ā§°’āĻā§āĻ¨ āĻšā§ā§°ā§āĻā§ąāĻžāĨ¤ 2. ā§°āĻŋāĻĄāĻžāĻāĻāĻ¨: āĻ āĻā§āĻ¸āĻŋāĻā§āĻ¨ āĻšā§ā§°ā§āĻā§ąāĻž āĻŦāĻž āĻšāĻžāĻāĻĄā§ā§°’āĻā§āĻ¨ āĻ˛āĻžāĻ āĻā§°āĻžāĨ¤
Q3. What are the properties of acids ? āĻāĻŽā§āĻ˛ā§° āĻā§āĻŖāĻ¸āĻŽā§āĻš āĻāĻŋ āĻāĻŋ ?
Ans: 1. Sour in taste 2. Turn blue litmus red 3. React with metals to produce hydrogen gas
āĻāĻ¤ā§āĻ¤ā§°: 1. āĻā§āĻāĻž āĻ¸ā§ā§ąāĻžāĻĻ āĻšāĻ¯āĻŧ 2. āĻ¨ā§āĻ˛āĻž āĻ˛āĻŋāĻāĻŽāĻžāĻ ā§°āĻāĻž āĻā§°ā§ 3. āĻ§āĻžāĻ¤ā§ā§° āĻ¸ā§āĻ¤ā§ āĻŦāĻŋāĻā§ā§°āĻŋāĻ¯āĻŧāĻž āĻā§°āĻŋ āĻšāĻžāĻāĻĄā§ā§°’āĻā§āĻ¨ āĻā§āĻ āĻā§āĻĒāĻ¨ā§āĻ¨ āĻā§°ā§
Q4. State the Modern Periodic Law. āĻāĻ§ā§āĻ¨āĻŋāĻ āĻĒā§°ā§āĻ¯āĻžāĻ¯āĻŧ āĻŦāĻŋāĻ§āĻŋ āĻāĻ˛ā§āĻ˛ā§āĻ āĻā§°āĻžāĨ¤
Ans : The properties of elements are periodic functions of their atomic numbers. āĻāĻ¤ā§āĻ¤ā§°: āĻŽā§āĻ˛āĻ¸āĻŽā§āĻšā§° āĻā§āĻŖāĻ¸āĻŽā§āĻš āĻ¤ā§āĻāĻāĻ˛ā§āĻā§° āĻĒāĻžā§°āĻŽāĻžāĻŖā§ąāĻŋāĻ āĻ¸āĻāĻā§āĻ¯āĻžā§° āĻĒā§āĻ¨ā§°āĻžāĻŦā§āĻ¤ā§āĻ¤āĻŋāĻŽā§āĻ˛āĻ āĻĢāĻ˛āĨ¤
Q5. What is an Indicator ? āĻ¸ā§āĻāĻ (Indicator) āĻāĻŋ ?
Ans: An indicator is a substance that changes colour in acidic or basic solutions.
Example: Litmus, Phenolphthalein. āĻāĻ¤ā§āĻ¤ā§°: āĻ¸ā§āĻāĻ āĻšā§āĻā§ āĻāĻ¨ā§ āĻāĻāĻž āĻĒāĻĻāĻžā§°ā§āĻĨ āĻ¯āĻŋāĻ¯āĻŧā§ āĻāĻŽā§āĻ˛ āĻŦāĻž āĻā§āĻˇāĻžā§° āĻĻā§ā§°āĻžā§ąāĻŖāĻ¤ ā§°āĻ āĻ¸āĻ˛āĻ¨āĻŋ āĻā§°ā§āĨ¤ āĻāĻĻāĻžāĻšā§°āĻŖ: āĻ˛āĻŋāĻāĻŽāĻžāĻ, āĻĢā§āĻ¨’āĻ˛āĻĢā§āĻĨā§āĻ˛āĻŋāĻ¨āĨ¤
Q6. Why can Carbon form a large number of compounds ? āĻāĻžā§°ā§āĻŦāĻ¨ā§ āĻāĻŋāĻ¯āĻŧ āĻŦāĻšā§ āĻ¸āĻāĻā§āĻ¯āĻ āĻ¯ā§āĻ āĻāĻ āĻ¨ āĻā§°āĻŋāĻŦ āĻĒāĻžā§°ā§ ?
Ans: Due to: 1. Catenation 2. Tetravalency
āĻāĻ¤ā§āĻ¤ā§°: āĻāĻžā§°āĻŖ- 1. āĻā§āĻā§āĻ¨ā§āĻāĻ¨ 2. āĻāĻ¤ā§ā§°ā§āĻŽā§āĻ˛āĻāĻ¤āĻž
Q7. What is a Redox Reaction ? ā§°ā§āĻĄāĻā§āĻ¸ āĻŦāĻŋāĻā§ā§°āĻŋāĻ¯āĻŧāĻž āĻāĻŋ ?
Ans: A reaction in which oxidation and reduction occur simultaneously. āĻāĻ¤ā§āĻ¤ā§°: āĻ¯āĻŋ āĻŦāĻŋāĻā§ā§°āĻŋāĻ¯āĻŧāĻžāĻ¤ āĻāĻā§ āĻ¸āĻŽāĻ¯āĻŧāĻ¤ā§ āĻ āĻā§āĻ¸āĻŋāĻĄā§āĻāĻ¨ āĻā§°ā§ ā§°āĻŋāĻĄāĻžāĻāĻāĻ¨ āĻāĻā§ āĻ¤āĻžāĻ ā§°ā§āĻĄāĻā§āĻ¸ āĻŦāĻŋāĻā§ā§°āĻŋāĻ¯āĻŧāĻž āĻŦā§āĻ˛ā§āĨ¤
Q8. State Faraday’s First Law of Electrolysis. āĻĢāĻžā§°āĻžāĻĄā§ā§° āĻĒā§ā§°āĻĨāĻŽ āĻāĻ˛ā§āĻā§āĻā§ā§°’āĻ˛āĻžāĻāĻāĻŋāĻ āĻŦāĻŋāĻ§āĻŋ āĻāĻ˛ā§āĻ˛ā§āĻ āĻā§°āĻžāĨ¤
Ans: The mass deposited is directly proportional to the quantity of electricity passed.
āĻāĻ¤ā§āĻ¤ā§°: āĻāĻŽāĻž āĻšā§ā§ąāĻž āĻĒāĻĻāĻžā§°ā§āĻĨā§° āĻā§° āĻĒā§ā§°āĻŦāĻžāĻšāĻŋāĻ¤ āĻŦāĻŋāĻĻā§āĻ¯ā§ā§ā§° āĻĒā§°āĻŋāĻŽāĻžāĻŖā§° āĻ¸ā§āĻ¤ā§ āĻ¸āĻŽāĻžāĻ¨ā§āĻĒāĻžāĻ¤āĻŋāĻāĨ¤
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Q1. Which of the following is an acid ? āĻ¤āĻ˛ā§° āĻā§āĻ¨āĻā§ āĻāĻŽā§āĻ˛ ?
A. NaOH B. HCl C. NaCl D. NHâOH
Ans / āĻāĻ¤ā§āĻ¤ā§°: B. HCl
Explanation: HCl releases Hâē ions in water, so it is an acid. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: HCl āĻĒāĻžāĻ¨ā§āĻ¤ Hâē āĻāĻ¯āĻŧāĻ¨ āĻā§°āĻŋ āĻĻāĻŋāĻ¯āĻŧā§, āĻ¸ā§āĻ¯āĻŧā§ āĻ āĻāĻŽā§āĻ˛āĨ¤
Q2. What is the pH value of a basic solution ? āĻā§āĻˇāĻžā§°ā§āĻ¯āĻŧ āĻĻā§ā§°āĻžā§ąāĻŖā§° pH āĻŽāĻžāĻ¨ āĻā§āĻ¨ā§āĻā§ā§ąāĻž ?
A. Less than 7 B. Equal to 7 C. Greater than 7 D. Zero
Ans: C. Greater than 7
Explanation: Bases have pH more than 7. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻā§āĻˇāĻžā§°ā§° pH āĻŽāĻžāĻ¨ ā§āĻ¤āĻā§ āĻŦā§āĻāĻŋ āĻšāĻ¯āĻŧāĨ¤
Q3. Which gas is released when acid reacts with metal ? āĻāĻŽā§āĻ˛ā§ āĻ§āĻžāĻ¤ā§ā§° āĻ¸ā§āĻ¤ā§ āĻŦāĻŋāĻā§ā§°āĻŋāĻ¯āĻŧāĻž āĻā§°āĻŋāĻ˛ā§ āĻā§āĻ¨āĻā§ āĻā§āĻ āĻāĻ˛āĻžāĻ¯āĻŧ ?
A. Oxygen B. Nitrogen C. Hydrogen D. Carbon dioxide
Ans: C. Hydrogen
Explanation: Acid + Metal → Salt + Hâ āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻāĻŽā§āĻ˛ + āĻ§āĻžāĻ¤ā§ → āĻ˛ā§ąāĻŖ + āĻšāĻžāĻāĻĄā§ā§°’āĻā§āĻ¨
Q4. Which element shows catenation property ? āĻā§āĻ¨āĻā§ āĻŽā§āĻ˛āĻ¤ āĻā§āĻā§āĻ¨ā§āĻāĻ¨ āĻā§āĻŖ āĻĻā§āĻāĻž āĻ¯āĻžāĻ¯āĻŧ ?
A. Oxygen B. Nitrogen C. Carbon D. Sulphur
Ans: C. Carbon
Explanation: Carbon forms long chains with itself. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻāĻžā§°ā§āĻŦāĻ¨ā§ āĻ¨āĻŋāĻā§° āĻ¸ā§āĻ¤ā§ āĻĻā§āĻāĻ˛ āĻļā§āĻāĻāĻ˛ āĻāĻ āĻ¨ āĻā§°ā§āĨ¤
Q5. What is used to test acidity in laboratory ? āĻ˛ā§āĻŦ’ā§°ā§āĻā§°ā§āĻ¤ āĻāĻŽā§āĻ˛ āĻĒā§°ā§āĻā§āĻˇāĻž āĻā§°āĻŋāĻŦāĻ˛ā§ āĻāĻŋ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻā§°āĻž āĻšāĻ¯āĻŧ ?
A. Thermometer B. Litmus C. Ammeter D. Barometer
Ans: B. Litmus
Explanation: Litmus changes colour in acid/base. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻ˛āĻŋāĻāĻŽāĻžāĻ āĻāĻŽā§āĻ˛ āĻŦāĻž āĻā§āĻˇāĻžā§°āĻ¤ ā§°āĻ āĻ¸āĻ˛āĻ¨āĻŋ āĻā§°ā§āĨ¤
Q6. Which of the following is a base ? āĻ¤āĻ˛ā§° āĻā§āĻ¨āĻā§ āĻā§āĻˇāĻžā§° ?
A. HâSOâ B. HNOâ C. NaOH D. HCl
Ans: C. NaOH
Explanation: NaOH releases OHâģ ions. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: NaOH āĻ OHâģ āĻāĻ¯āĻŧāĻ¨ āĻā§°āĻŋ āĻĻāĻŋāĻ¯āĻŧā§āĨ¤
Q7. What happens during oxidation ? āĻ āĻā§āĻ¸āĻŋāĻĄā§āĻāĻ¨ā§° āĻ¸āĻŽāĻ¯āĻŧāĻ¤ āĻāĻŋ āĻšāĻ¯āĻŧ ?
A. Gain of hydrogen B. Loss of oxygen C. Gain of oxygen D. Loss of electrons only
Ans: C. Gain of oxygen
Explanation: Oxidation means gain of oxygen. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻ
āĻā§āĻ¸āĻŋāĻĄā§āĻāĻ¨ āĻŽāĻžāĻ¨ā§ āĻ
āĻā§āĻ¸āĻŋāĻā§āĻ¨ āĻ˛āĻžāĻ āĻā§°āĻžāĨ¤
Q8. Which indicator turns pink in base ? āĻā§āĻ¨āĻā§ āĻ¸ā§āĻāĻā§ āĻā§āĻˇāĻžā§°āĻ¤ āĻā§āĻ˛āĻĒā§āĻ¯āĻŧāĻž ā§°āĻ āĻšāĻ¯āĻŧ ?
A. Litmus B. Methyl orange C. Phenolphthalein D. Turmeric
Ans: C. Phenolphthalein
Explanation: Phenolphthalein turns pink in base. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻĢā§āĻ¨’āĻ˛āĻĢā§āĻĨā§āĻ˛āĻŋāĻ¨ āĻā§āĻˇāĻžā§°āĻ¤ āĻā§āĻ˛āĻĒā§āĻ¯āĻŧāĻž āĻšāĻ¯āĻŧāĨ¤
Q9. The atomic number of an element is based on number of ____? Q9. āĻāĻāĻž āĻŽā§āĻ˛ā§° āĻĒāĻžā§°āĻŽāĻžāĻŖā§ąāĻŋāĻ āĻ¸āĻāĻā§āĻ¯āĻž āĻāĻŋāĻšā§° āĻāĻĒā§°āĻ¤ āĻ¨āĻŋā§°ā§āĻā§° āĻā§°ā§ ?
A. Neutrons B. Electrons C. Protons D. Ions
Ans: C. Protons
Explanation: Atomic number = number of protons. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻĒāĻžā§°āĻŽāĻžāĻŖā§ąāĻŋāĻ āĻ¸āĻāĻā§āĻ¯āĻž = āĻĒā§ā§°’āĻāĻ¨ā§° āĻ¸āĻāĻā§āĻ¯āĻžāĨ¤
Q10. Which law relates mass and electricity in electrolysis ? āĻāĻ˛ā§āĻā§āĻā§ā§°’āĻ˛āĻžāĻāĻāĻŋāĻāĻ¤ āĻā§° āĻā§°ā§ āĻŦāĻŋāĻĻā§āĻ¯ā§ā§ āĻā§āĻ¨āĻā§ āĻŦāĻŋāĻ§āĻŋāĻ¯āĻŧā§ āĻ¸āĻŽā§āĻĒā§°ā§āĻāĻŋāĻ¤ āĻā§°ā§ ?
A. Ohm’s Law B. Faraday’s First Law C. Newton’s Law D. Boyle’s Law
Ans: B. Faraday’s First Law
Explanation: It relates mass deposited to electric charge. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻ āĻāĻŽāĻž āĻšā§ā§ąāĻž āĻā§° āĻā§°ā§ āĻŦāĻŋāĻĻā§āĻ¯ā§ā§ā§° āĻĒā§°āĻŋāĻŽāĻžāĻŖā§° āĻ¸āĻŽā§āĻĒā§°ā§āĻ āĻĻā§āĻā§ā§ąāĻžāĻ¯āĻŧāĨ¤
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Q11. Which substance has pH less than 7 ? āĻā§āĻ¨āĻā§ āĻĒāĻĻāĻžā§°ā§āĻĨā§° pH āĻŽāĻžāĻ¨ ā§āĻ¤āĻā§ āĻāĻŽ ?
A. Soap B. Lime water C. Vinegar D. Baking soda
Ans: C. Vinegar
Explanation: Vinegar is acidic, so pH < 7. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻāĻŋāĻ¨ā§āĻāĻžā§° āĻāĻŽā§āĻ˛ā§āĻ¯āĻŧ, āĻ¸ā§āĻ¯āĻŧā§ pH ā§āĻ¤āĻā§ āĻāĻŽāĨ¤
Q12. Which gas is used in the manufacture of fertilizers ? āĻ¸āĻžā§° āĻĒā§ā§°āĻ¸ā§āĻ¤ā§āĻ¤āĻŋāĻ¤ āĻā§āĻ¨āĻā§ āĻā§āĻ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻā§°āĻž āĻšāĻ¯āĻŧ ?
A. Oxygen B. Hydrogen C. Nitrogen D. Carbon dioxide
Ans: C. Nitrogen
Explanation: Nitrogen is essential for fertilizers. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻ¸āĻžā§°āĻ¤ āĻ¨āĻžāĻāĻā§ā§°’āĻā§āĻ¨ āĻ
āĻ¤āĻŋ āĻĒā§ā§°āĻ¯āĻŧā§āĻāĻ¨ā§āĻ¯āĻŧāĨ¤
Q13. Which metal is most reactive ? āĻā§āĻ¨āĻā§ āĻ§āĻžāĻ¤ā§ āĻāĻāĻžāĻāĻ¤āĻā§ āĻ āĻ§āĻŋāĻ āĻĒā§ā§°āĻ¤āĻŋāĻā§ā§°āĻŋāĻ¯āĻŧāĻžāĻļā§āĻ˛ ?
A. Copper B. Iron C. Sodium D. Silver
Ans: C. Sodium
Explanation: Sodium is highly reactive alkali metal. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻ’āĻĄāĻŋāĻ¯āĻŧāĻžāĻŽ āĻ
āĻ¤ā§āĻ¯āĻ¨ā§āĻ¤ āĻĒā§ā§°āĻ¤āĻŋāĻā§ā§°āĻŋāĻ¯āĻŧāĻžāĻļā§āĻ˛ āĻ§āĻžāĻ¤ā§āĨ¤
Q14. Which of the following is not a compound ? āĻ¤āĻ˛ā§° āĻā§āĻ¨āĻā§ āĻ¯ā§āĻ āĻ¨āĻšāĻ¯āĻŧ ?
A. Water B. Salt C. Oxygen D. Carbon dioxide
Ans: C. Oxygen
Explanation: Oxygen is an element, not a compound. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻ
āĻā§āĻ¸āĻŋāĻā§āĻ¨ āĻāĻāĻž āĻŽā§āĻ˛, āĻ¯ā§āĻ āĻ¨āĻšāĻ¯āĻŧāĨ¤
Q15. What is the chemical formula of washing soda ? ā§ąāĻžāĻļāĻŋāĻ āĻ’āĻĄāĻžā§° ā§°āĻžāĻ¸āĻžāĻ¯āĻŧāĻ¨āĻŋāĻ āĻ¸āĻāĻā§āĻ¤ āĻāĻŋ ?
A. NaHCOâ B. NaâCOâ·10HâO C. NaâCOâ D. CaCOâ
Ans: B. NaâCOâ·10HâO
Explanation: Washing soda is hydrated sodium carbonate. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: ā§ąāĻžāĻļāĻŋāĻ āĻ’āĻĄāĻž āĻšā§āĻā§ āĻšāĻžāĻāĻĄā§ā§°ā§āĻā§āĻĄ āĻ’āĻĄāĻŋāĻ¯āĻŧāĻžāĻŽ āĻāĻžā§°ā§āĻŦ’āĻ¨ā§āĻāĨ¤
Q16. Which process is used to prevent rusting ? āĻŽā§°āĻā§ āĻ§ā§°āĻž ā§°ā§āĻ§ āĻā§°āĻŋāĻŦāĻ˛ā§ āĻā§āĻ¨āĻā§ āĻĒā§ā§°āĻā§ā§°āĻŋāĻ¯āĻŧāĻž āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻā§°āĻž āĻšāĻ¯āĻŧ ?
A. Oxidation B. Galvanization C. Reduction D. Combustion
Ans: B. Galvanization
Explanation: Zinc coating prevents rusting. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻāĻŋāĻāĻā§° āĻāĻŦā§°āĻŖā§ āĻŽā§°āĻā§ āĻ§ā§°āĻž ā§°ā§āĻ§ āĻā§°ā§āĨ¤
Q17. Which acid is present in lemon ? āĻ˛ā§āĻŦā§āĻ¤ āĻā§āĻ¨āĻā§ āĻāĻŽā§āĻ˛ āĻĨāĻžāĻā§ ?
A. Acetic acid B. Citric acid C. Lactic acid D. Hydrochloric acid
Ans: B. Citric acid
Explanation: Lemon contains citric acid. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻ˛ā§āĻŦā§āĻ¤ āĻ¸āĻžāĻāĻā§ā§°āĻŋāĻ āĻāĻŽā§āĻ˛ āĻĨāĻžāĻā§āĨ¤
Q18. Which element is essential for corrosion of iron ? āĻ˛ā§āĻšāĻžā§° āĻŽā§°āĻā§ āĻ§ā§°āĻŋāĻŦāĻ˛ā§ āĻā§āĻ¨āĻā§ āĻŽā§āĻ˛ āĻā§ąāĻļā§āĻ¯āĻ ?
A. Hydrogen B. Nitrogen C. Oxygen D. Carbon
Ans: C. Oxygen
Explanation: Oxygen is required for rusting. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻŽā§°āĻā§ āĻ§ā§°āĻŋāĻŦāĻ˛ā§ āĻ
āĻā§āĻ¸āĻŋāĻā§āĻ¨ āĻĒā§ā§°āĻ¯āĻŧā§āĻāĻ¨āĨ¤
Q19. What type of reaction is photosynthesis ? āĻĒā§ā§°āĻāĻžāĻļ-āĻ¸āĻāĻļā§āĻ˛ā§āĻˇāĻŖ āĻā§āĻ¨ āĻĒā§ā§°āĻāĻžā§°ā§° āĻŦāĻŋāĻā§ā§°āĻŋāĻ¯āĻŧāĻž ?
A. Endothermic B. Exothermic C. Neutralization D. Redox
Ans: A. Endothermic
Explanation: It absorbs energy from sunlight. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻ āĻ¸ā§ā§°ā§āĻ¯ā§° āĻļāĻā§āĻ¤āĻŋ āĻļā§āĻˇāĻŖ āĻā§°ā§āĨ¤
Q20. Which compound is used in fire extinguishers ? āĻ āĻā§āĻ¨āĻŋāĻ¨āĻŋā§°ā§āĻŦāĻžāĻĒāĻ āĻ¯āĻ¨ā§āĻ¤ā§ā§°āĻ¤ āĻā§āĻ¨āĻā§ āĻ¯ā§āĻ āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻā§°āĻž āĻšāĻ¯āĻŧ ?
A. Sodium chloride B. Sodium bicarbonate C. Calcium carbonate D. Potassium chloride
Ans: B. Sodium bicarbonate
Explanation: It releases COâ to stop fire. āĻŦā§āĻ¯āĻžāĻā§āĻ¯āĻž: āĻ COâ āĻā§āĻ āĻā§°āĻŋ āĻāĻā§āĻ¨ āĻ¨āĻŋāĻŦāĻžā§°āĻŖ āĻā§°ā§āĨ¤