Worksheet: Reduction–Oxidation Titrations
In this worksheet, we will practice describing iodometry, iodimetry, and other redox titration methods and troubleshooting common errors.
Triiodide ions are produced by the reaction of iodine with iodide ions. Why should iodine solutions contain an additional iodide salt if used as a titrant?
- ATriiodide salts are more soluble in water than iodine.
- BTriiodide ions undergo a more visible color change during reduction–oxidation reactions.
- CTriiodide ions are more strongly oxidizing than iodine.
- DTriiodide ions are more highly colored than iodine in water.
- ETriiodide ions are more stable than iodine when stored under air.
Which of the following is an accurate description of iodometry?
- AExcess analyte is reacted with iodine, and the remainder is titrated against sodium thiosulfate.
- BIodine is used as a titrant for an oxidizing analyte.
- CIodine is used as a titrant for a reducing analyte.
- DExcess sodium thiosulfate is reacted with an analyte, and the remainder is titrated against iodine.
- EExcess iodide is reacted with an analyte, and the resulting iodine is titrated against sodium thiosulfate.
Which of the following would not improve the accuracy of an iodometric titration?
- AUsing only fresh thiosulfate solutions
- BUsing excess iodide in the iodine solution
- CUsing only fresh iodide solutions
- DAdding starch indicator to the iodine solution
- ELowering the pH of an acidic analyte solution
Copper(II) nitrate reacts with potassium iodide in water to produce solid copper(I) iodide and elemental iodine, as shown.
A copper(II) nitrate solution has a volume of 43.88 mL and concentration of 0.3842 M. Calculate the volume of a 0.2089 M potassium iodide solution needed to convert all of the copper(II) nitrate to copper(I) iodide.
- A161.4 mL
- B180.0 mL
- C153.0 mL
- D179.4 mL
- E175.1 mL
Adding aqueous sodium chloride to aqueous silver nitrate results in the precipitation of silver chloride, as shown. Calculate the concentration of silver nitrate in a 23.00 mL aqueous sample if 32.10 mL of 0.203 M aqueous sodium chloride is required for the end point to be reached.
- A0.283 M
- B0.270 M
- C0.145 M
- D0.128 M
- E0.203 M