Conductometric Methods and Titrations Lecture Notes

Flashcards based on conductometric methods and titrations.

Where is the lecturer's office?

Building 3, Room 614D, Arcadia Campus

What are the lecture days, times, and venues?

Monday (Practical): 08h00-11h00 3-524; Wednesday (Theory): 11h30-13h00 4-420; Thursday (Theory): 08h00-09h30 3-605

When is Test 1?

14 March 2023A

When is Test 2?

11 April 2023A

When is Test 3?

02 May 2023A

When is the Sick Test?

08 – 12 May 2023A

Who are the class representatives?

Vanessa Keitumetse Mampane, [e-mail], 068 221 8821; Masingita Ashley Maboya, [e-mail], 076 266 2260

What is conductometry?

Measurement of conductivity providing information about the total ionic content of aqueous solutions.

How do solutions of electrolytes conduct electric current?

Electrical current is developed due to migration of positively charged ions towards cathode and negatively charged ions towards anode.

What is the conductometric method?

Electrochemical method of analysis used for the determination or measurement of the electrical conductance of an electrolyte solution by means of a conductometer.

What two factors affect conductance?

Speed of ions and their concentration

What are the two types of conductors?

Metallic (flow of electrons) or electrolytic (movement of ions, or charged species).

On what does the conductivity of an electrolyte solution depend?

Type of ions, concentrations of ions, temperature, mobility of ions

Give some examples of electrolytes.

NaCl, KCl, etc.

Give some examples of non-electrolytes.

Cane sugar, benzene, carbon tetrachloride, etc.

What are true electrolytes?

Exist as ions in their normal and molten states and ionize when dissolved in water (e.g., NaCl, KCl).

What are potential electrolytes?

Do not conduct electricity in their pure normal state but do when dissolved in water (e.g., HCl, CH3COOH, NH3).

What are strong electrolytes?

Completely ionized in aqueous solutions (e.g., NaCl, NH4Cl, KNO3, HCl, HBr, etc.).

What are weak electrolytes?

Ionize only to a certain extent in aqueous solutions (e.g., CH3COOH, HCN, etc.).

What are the main components of a conductometer?

Current source (alternating current), conductivity cells, and electrodes.

How is electrical conductance defined?

Ease with which current flows through the solution; inversely proportional to resistance.

What is the unit of conductance?

Ohm-1 or Siemens (S).

What causes the flow of electricity through an electrolyte solution?

Migration of ions upon applying voltage between two electrodes.

What are the three types of conductance?

Specific conductance, equivalent conductance, and molar conductance.

What is specific conductance/conductivity (κ)?

Conductance of the solution between two electrodes separated by 1 m length and an area of 1 m2.

What is equivalent conductance (Λeq)?

Conductance of a solution containing one gram equivalent weight of the electrolyte.

What is molar conductance (ΛM)?

Conductance of a solution containing one molecular concentration (1M) of the electrolyte.

What is the formula for cell constant?

Kcell = l/a

What factors affect conductivity?

Types of ions, charge of ions, mobility of ions, concentration of ions, and temperature.

How is the equivalence point located in conductometric titration?

Graphical plotting of conductance change as a function of titrant volume to locate the equivalence point.

What are the types of conductometric titration?

Acid-base, replacement, redox, precipitation