NTSE Chemistry Acids Bases and Salts MCQs

Question: Which of the following represents acid-base pair for the equilibrium reaction ?

• a) HCI, H2O              
• b) HCI, H3O+       
• c) HCI, CI- 
• d) CI-, H2O

Answer: HCI, CI- 

Question: The strongest acid of the following is -

• a) HCI
• b) H2SO4  
• c) HCIO4 
• d) H3PO4

Answer: HCIO4 

Question: Acids are the substances that yield H⁺ ions in aqueous solutions while bases yield OH^- ions. In a neutral solution -

• a) There are no H+ ions.
• b) There are no OH- ions.
• c) There are neither H+ nor OH- ions.
• d) H+ and OH- ions are present in very small but equal in number

Answer: H+ and OH- ions are present in very small but equal in number

Question: The reaction of water with ammonia is given by the following equation, in this reaction water acts as :

• a) Neutral
• b) Base
• c) Acid
• d) Both acid and base

Answer: Acid

Question: Ionic theory of acid and bases was proposed by -

• a) Lowry
• b) Bronsted
• c) Lewis
• d) Arthenius

Answer: Arthenius

Question: The conjugate acid of NH2- is -           

• a) NH3     

   

• b) NH2OH  
• c) NH4+ 
• d) CIO4-

Answer: NH3     

Question: The strength of the acid depends on the -

• a) Number of hydrogen atoms present in the molecules.
• b) Density.
• c) Oxygen content.
• d) Concentration of hydrogen ions furnished by ionisation.

Answer: Concentration of hydrogen ions furnished by ionisation.

Question: According to Lewis concept, the acid is -

• a) Proton acceptor.
• b) Electron pair donor.
• c) Electron pair acceptor
• d) Proton donor.

Answer: Electron pair acceptor

Question: Which of the following could act as a Lewis acid but not Bronsted acid ?

• a) HCI
• b) H2SO4 
• c) HSO3- 
• d) SO3

Answer: SO3

Question: Which among the following is a Lewis acid ?

• a) NaF
• b) BF4  
• c) NaCI
• d) MgCI2

Answer: BF4  

Question: The pH of a solution is 3. When it’s pH changes to 6 then H+ ion concentration -

• a) Increases three times.
• b) Increases two times
• c) Decrease 100 times
• d) Decreases 1000 times.

Answer: Decreases 1000 times.

Question: At 800C, pure distilled water has H3O+ concentration equal to 1 × 10^-6 mol L^-1. The value of K_w at this temperature will be -           

• a) 1 × 10^-8      
• b) 1 × 10^-12   
• c) 1 × 10^-14    
• d) 1 × 10^-6

Answer: 1 × 10^-12   

Question: What happens when dil. H2SO4 is added to baking soda ?

• a) SO2 gas is evolved.    
• b) Sodium sulphate is formed.
• c) An acid salt is produced.
• d) All of the above.

Answer: Sodium sulphate is formed.

Question: Bleaching powder is commercially called -

• a) Chloride of lime only
• b) Chlorinated lime only
• c) Both
• d) None

Answer: Both

Question: Which among the following is a Lewis acid ?

• a) NaF
• b) Nacl
• c) MgCl₂
• d) BF₄

Answer: BF₄