MCQs on Titration

Titration or volumetric analysis is a method used in the laboratory to determine the concentration of an unknown solution. It is a quantitative method of chemical analysis. In this, a titrant of known concentration is prepared and used to react with the analyte to determine its concentration. The volume of titrant, which reacts with the analyte is known as titre volume. There are different types of reactions used in titration. The most common is the acid-base titration and redox titration. An indicator is used to determine the endpoint, which is indicated by the colour change.

1. Which of the following is used as an indicator in the titration of iodine with hypo?

(a) Methyl red

(b) Methyl orange

(c) Starch

(d) Potassium ferricyanide

Answer: (c)

2. What will be the pH at the equivalence point in the titration of a weak acid and a strong base?

(a) 0

(b) >7

(c) 7

(d) <7

Answer: (b)

3. On adding a large amount of titrant, an asymptote is obtained in the titration curve, this asymptote represents

(a) K_a of the initial solution

(b) pH of the initial solution

(c) pH of the titrant

(d) none of the above

Answer: (c)

4. The buffer region is represented by

(a) the concave curve after adding titrant

(b) the flat curve before the equivalence point

(c) the flat curve after the equivalence point

(d) the steep curve after the equivalence point

Answer: (b)

5. How many mmols of NaOH will be used in the titration with 33ml of 3 M HCl to form NaCl and water?

(a) 10 mmol

(b) 100 mmol

(c) 3 mmol

(d) 33 mmol

Answer: (b)

6. The pH range of methyl orange as an indicator is

(a) 3-5

(b) 8-9

(c) 2-4

(d) 6-8

Answer: (a)

7. The amount of NaOH used in the titration of 100 ml 0.1 N HCl is

(a) 4 g

(b) 0.04 g

(c) 2 g

(d) 0.4 g

Answer: (d)

8. The equivalent weight of an acid can be calculated by

(a) Molecular weight × basicity

(b) Molecular weight/basicity

(c) Molecular weight × acidity

(d) Molecular weight/acidity

Answer: (b)

9. The normal rain water is acidic due to

(a) SO₂

(b) NO₂

(c) NH₃

(d) CO₂

Answer: (d)

10. Which of the following represents the equivalence point in the graph of pH Vs volume of titrant?

(a) Point at the highest pH

(b) Point at the greatest magnitude of the slope of the curve

(c) Point at the lowest pH

(d) Point at the least magnitude of the slope of the curve

Answer: (b)