H2SO4 is considered a strong acid because it will completely dissociate in solution. What does that mean
The correct answer and explanation is:
H₂SO₄, or sulfuric acid, is considered a strong acid because it completely dissociates in aqueous solution. This means that when sulfuric acid is dissolved in water, it breaks apart entirely into its ions. Specifically, the H₂SO₄ molecule separates into two hydrogen ions (H⁺) and one sulfate ion (SO₄²⁻).
Complete dissociation means that virtually every molecule of sulfuric acid releases its hydrogen ions into the solution. There are no or very few undissociated H₂SO₄ molecules left in the water. This is different from weak acids, which only partially dissociate and exist in equilibrium between their ionized and non-ionized forms.
The significance of complete dissociation is that the concentration of hydrogen ions in the solution is equal to the initial concentration of the acid (for the first dissociation step). This results in a high concentration of free hydrogen ions, making the solution very acidic. The presence of free hydrogen ions is what causes the characteristic acidic properties, such as a low pH and the ability to react strongly with bases or metals.
In the case of sulfuric acid, the first hydrogen ion dissociates completely:
H₂SO₄ → H⁺ + HSO₄⁻
The second dissociation of the bisulfate ion (HSO₄⁻) is only partial, so it behaves somewhat like a weak acid:
HSO₄⁻ ⇌ H⁺ + SO₄²⁻
Because the first hydrogen ion dissociates fully, sulfuric acid is classified as a strong acid. This strong acidic nature makes it widely used in industries and laboratories where a highly acidic environment is needed. It also means it can be very corrosive and must be handled with care.
In summary, complete dissociation means sulfuric acid fully breaks apart to release hydrogen ions, resulting in a highly acidic solution with very few molecules remaining intact.