The equivalent mass of sulphuric acid is 49u.
Understanding Equivalent Mass
Equivalent mass, also known as equivalent weight, is a crucial concept in chemistry, especially when dealing with reactions involving acids and bases. It's different from molecular mass and takes into account the number of replaceable hydrogen or hydroxide ions.
Calculating Equivalent Mass
The formula for equivalent mass is:
Equivalent mass = Molecular mass / Number of replaceable hydrogen ions (for acids) or hydroxide ions (for bases)
Sulphuric Acid (H₂SO₄) Example
-
Molecular Mass of Sulphuric Acid:
- Hydrogen (H) = 1u
- Sulphur (S) = 32u
- Oxygen (O) = 16u
- Molecular mass of H₂SO₄ = (2 1) + 32 + (4 16) = 2 + 32 + 64 = 98u
-
Number of Replaceable Hydrogen Ions:
- Sulphuric acid (H₂SO₄) has two replaceable hydrogen ions.
-
Equivalent Mass Calculation:
- Equivalent mass of H₂SO₄ = 98u / 2 = 49u
Key Points to Remember
- The equivalent mass of an acid is the mass that can furnish one mole of hydrogen ions (H+).
- Sulphuric acid is a diprotic acid, meaning it can donate two protons (H+) per molecule.
- The equivalent mass concept is important for stoichiometry calculations, especially in volumetric analysis.
| Property | Value |
|---|---|
| Molecular Mass | 98 u |
| Replaceable H ions | 2 |
| Equivalent Mass | 49 u |
