Acid-Base Titrations Overview

Study Notes

Standard solutions are solutions with a known concentration and composition.
Primary Standard is a solution of exactly known concentration.
- It is used to accurately determine the concentration of other solutions.
Requirements for a primary standard substance:
- Must be easily obtainable in a high grade of purity and of known composition.
- Stable and resists reactions with air.
- Not deliquescent or hygroscopic, and not volatile.
- Can be dried at 105-110°C without decomposition.
- Has a relatively high molecular weight.
- Reacts quantitatively with other substances.
Examples of primary standard substances:
- Acids: Potassium acid phthalate, oxalic acid, benzoic acid.
- Bases: Sodium carbonate, Borax (sodium borate).
Secondary Standard is a solution with an approximately known concentration.
- Its exact concentration is determined through a process called standardization.
- Standardization involves titrating the secondary standard solution against a primary standard solution or a previously standardized secondary standard.
Examples of secondary standard substances:
- HCl and NaOH.

Molarity (M):
- Number of moles of solute per 1 Liter of solution.
- Formula: M = (Number of moles of solute) / (Volume in L of solution)
Normality (N):
- Number of equivalent weights of solute per 1 Liter of solution.
- Formula: N = (Number of equivalent weights of solute) / (Volume in L of solution)

For molecules:
- The mole is gram-molecular weight (molecular weight expressed in grams).
For atoms:
- The mole is gram-atomic weight (atomic weight expressed in grams).

The weight of a substance that is equivalent in its reactive power to 1 mole of hydrogen.
Calculation of equivalent weight depends on the type of reaction.
This lecture focuses on acid-base reactions.