Acid Base Titration MCQs

Q1. In the titration of a strong acid and a weak base, which of the following is used as an indicator?

1. 1. Methyl orange
   2. Phenolphthalein
   3. Thymol blue
   4. Fluorescein

 Answer : a) Methyl orange

Q2. The optimal indicator for strong acid and weak base titration should have a pH range of .

1. 1. 3-5
   2. 4-6
   3. 6-8
   4. 7-9

 Answer : b) 4-6

Q3. Determine the concentration of HCl if it takes 10 ml of 0.5 M Ca(OH)2 to titrate 50 ml of HCl.

1. 1. 1/10 M
   2.  1/5 M
   3. 5 M
   4. 10 M

View Answer : b) 1/5 M

Q4. What is the concentration of the sulphuric acid solution if 50 ml of 0.5 M Ba(OH)2 solution is added to 100 ml of the solution?

1. 1. 0.25 M
   2. 0.5 M
   3. 25 M
   4. 50 m

Answer : a) 0.25 M

 Q5. When 30 ml of acid is neutralised by 15 ml of 0.2 N alkali, the acid concentration is ______

1. 1. 0.1 N
   2. 0.2 N
   3. 0.3 N
   4. 0.4 N

Answer : a) 0.1 N

Q6. Which of the following is an example of a buffer solution?

1. 1. CH3COOH + CH3COONH4
   2. H2SO4 + CuSO4
   3. CH3COONa + CH3COOH
   4. NaCl + NaOH

Answer : c) CH3COONa + CH3 COOH

Q7. In the titration of a weak acid and a strong base, which of the following is utilised as an indicator?

1. 4. Methyl orange (3 to 4.6)
   5. Bromothymol blue (6 to 7.5)
   6. Phenolphthalein (8 to 9.6)
   7. Methyl red (5 to 6.9)

Answer : c) Phenolphthalein (8 to 9.6)

Q8. What is the molarity of the barium hydroxide solution if 35 ml of 0.1 M HCl is used in the titration of 25 ml of barium hydroxide solution?

1. 1. 0.28
   2. 0.21
   3. 0.14
   4. 0.07

Answer : d) 0.07

Q9. The distinction between strong and mild acid is .

1. 1. proton donation and electron acceptance
   2. complete and partial ionisation
   3. negative and positive pH
   4. presence and absence of halogen ions

Answer : a) proton donation and electron acceptance

Q10. Which of the following titrations has an equivalence point at pH greater than 8?

1. 1. CH3COOH and NaOH
   2.  HCl and NaOH
   3. CH3COOH and NH3
   4. HCl and NH3

 Answer : a) CH3COOH and NaOH

Q11.How concentrated are H30+ ions in pure water?

1. 1. 10^-7 M
   2. 0.7 M
   3. 55.4 M
   4. 10^7 M

Answer : a)10^-7 M

Q12.What is the sum of the concentrations of H3O+ions and OH- ions in water?

1. 1. 10^-28
   2. 10^-14
   3. 10^-7
   4. 55.4

Answer : b) 10^-14

 Q13.If the [H3O+] of a solution is less than the [OH-], the solution is

1. 1. is alays acidic
   2. is always basic
   3. is always neutral
   4. might be acidic, basic, or neutral

Answer : b) is always basic

Q14. In general, the pH scale spans from

1. 1. 0-1
   2. -1-1
   3. 0-7
   4. 0-14

Answer : d) 0-14

Q15.A water solution with a pH of 10 is 

1. 1. is always acidic
   2. is always basic
   3. is always neutral
   4. might be acidic, basic, or neutral

Answer : a) always acidic

Q16.How acidic is a 10-4 M HCl solution?

1. 1. 4
   2. 6
   3. 8
   4. 10

Answer : a)4

Q18.In the equation below, how would you classify KOH?

KOH(aq) —> K+(aq) + OH-(aq)

1. 1. a weak acid
   2. a strong acid
   3. a weak base
   4. a strong base

Answer : d) a strong base 

Q19.A solution’s pH is 9.0. What is the concentration of H3O+ in it?

1. 1. 1×10^-9 M
   2. 1×10^-7 M
   3. 1×10^-5 M
   4. 9 M

Answer :  a) 1×10^-9 M

Q 20.A solution’s pH is 10.0. What is the concentration of OH- in it?

1. 1. 1.0×10^-10
   2. 1.0×10^-7
   3. 1.0×10^-4
   4. 10 M

Answer : c) 1.0×10^-4

Q21. What is the molarity of the barium hydroxide solution if 35 ml of 0.1 M HCl is used to titrate 25 ml of barium hydroxide solution?

1. 1. 0.35
   2. 0.07
   3. 0.28
   4. 0.14

Answer : (b)0.07 

Q22. Which of the following titrations has a pH greater than 8 equivalence point?

1. 1. HCl and NH3
   2. CH3COOH and NH3
   3. HCl and NaOH
   4. CH3COOH and NaOH

Answer : (d) CH3COOH and NaOH

Q23. Which of the following is used as an indicator in the titration of a strong acid and a weak base?

1. 1. Phenolphthalein
   2. Thymol blue
   3. Fluorescein
   4. Methyl orange

Answer: (d) Methyl Orange

Q24. Which of the following is used as an indicator in the titration of a weak acid and a strong base?

1. 1. Bromothymol blue (6 to 7.5)
   2. Methyl orange (3 to 4)
   3. Methyl red (5 to 6)
   4. Phenolphthalein (8 to 9.6)

Answer: (d)  Phenolphthalein (8 to 9.6)

Q25. The ideal indicator for titration of strong acid and weak base should have a pH range of between

1. 1.  5-8
   2. 4-6
   3. 8-10
   4. 7-8

Answer : (b) 4-6

Q26. What is the difference between strong and weak acid?

1. 1. presence and absence of halogen ions
   2. negative and positive pH
   3. complete and partial ionisation
   4. proton donation and electron acceptance

Answer : (c) complete and partial ionisation

Q27. Determine the concentration of HCl if 10 ml of 0.5 M Ca(OH)2 is required to titrate 50 ml of HCl.

1. 1. 5 M
   2. 1/10 M
   3. 10 M
   4. 1/5 M

Answer : (d) 1/5 M

Q28. The acid concentration is determined by neutralising 30 mL of acid with 15 mL of 0.2 N alkali.

1. 1. 0.4 N
   2. 0.1 N
   3. 0.3 N
   4. 0.15 N

Answer: (b) 0.1 N

Also see:

• MCQs on p block Elements
• Acid Rain MCQs
• MCQs On Afbau Principle