Question 1

Which step in the titration process, as shown in the first image, corresponds to the detection of the equivalence point?

Accepted Answer

Step (c): Colour change indicates reaction is complete

Question 2

In the context of titrimetric analysis, what is the primary purpose of the colour change observed in the conical flask during titration?

Accepted Answer

To indicate that the equivalence point has been reached

Question 3

The complex shown in the second image contains a central metal ion surrounded by several ligands. What type of titration is most relevant for the analysis of such a complex?

Accepted Answer

Complexometric titration

Question 4

Which of the following best describes a ligand in the context of the complex shown in the second image?

Accepted Answer

A molecule that donates electrons to the metal ion

Question 5

During a titration, why is it important to choose an indicator whose end point is as close as possible to the equivalence point?

Accepted Answer

To maximize the accuracy of the titration result

Question 6

Which of the following equations correctly relates the molarity and volume of titrant and titrand in a titration with stoichiometric coefficients $$a$$ and $$b$$?

Accepted Answer

$$M_A V_A / a = M_B V_B / b$$

Question 7

A student titrates 25.0 mL of a Ca$$^{2+}$$ solution with 0.0100 mol dm$$^{-3}$$ EDTA. The end point is reached after 18.5 mL of EDTA is added. What is the molarity of the Ca$$^{2+}$$ solution? (Assume 1:1 stoichiometry.)

Accepted Answer

$$0.00740$$ mol dm$$^{-3}$$

Question 8

Which of the following is NOT a requirement for a primary standard used in titrant standardization?

Accepted Answer

It must be highly soluble in organic solvents

Question 9

In a redox titration, which of the following statements is TRUE regarding the roles of oxidant and reductant?

Accepted Answer

The oxidant gains electrons and is reduced

Question 10

Which of the following best explains why chloride ions must be absent in a permanganate titration?

Accepted Answer

Chloride ions act as an interferent, reacting with permanganate and causing inaccurate results

Question 11

A titration curve shows a rapid pH change near the equivalence point and the equivalence point occurs at pH \u003e 7. Which combination of acid and base does this most likely represent?

Accepted Answer

Weak acid and strong base

Question 12

Which indicator would be most suitable for the titration of acetic acid (CH$$_3$$COOH) with sodium hydroxide (NaOH)?

Accepted Answer

Phenolphthalein

Question 13

Which of the following is a correct balanced half-reaction for the reduction of permanganate in acidic solution?

Accepted Answer

$$\mathrm{MnO_4^- + 8 H^+ + 5 e^- \rightarrow Mn^{2+} + 4 H_2O}$$

Question 14

A 1.00 g sample of aspirin (acetylsalicylic acid, MW = 180 g/mol) is titrated with 0.50 mol dm$$^{-3}$$ NaOH. If 4.43 mL of NaOH are required to reach the end point, what is the percentage of active ingredient in the tablet?

Accepted Answer

39.9%

Question 15

Which of the following is a key advantage of using instrumental indication (e.g., pH meter) over visual indicators in titrations?

Accepted Answer

Instrumental methods provide more precise determination of the equivalence point

Question 16

Which of the following best describes the role of EDTA in a complexometric titration?

Accepted Answer

It acts as a ligand, binding to metal ions to form stable complexes

Analytical Chemistry: Core Concepts and Titrimetric Methods

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