Concentration "molarity" of H₂SO₄ in this solution:
5 × 10⁻³ mol / dm³.
Explanation
What's the concentration of H⁺ ions in this solution?
[tex][\text{H}^{+}] = 10^{-\text{pH}}[/tex],
where [tex][\text{H}^{+}][/tex] is in the unit mol / dm³.
[tex]\text{pH} = 2 [/tex]
[tex][\text{H}^{+}] = 10^{-2} \;\text{mol}\cdot\text{dm}^{-3}[/tex].
What's the concentration "molarity" of H₂SO₄ in this solution?
Sulfuric acid H₂SO₄ is a strong acid. Note the subscript "2". Each mole of this acid dissolves in water to produce two moles of H⁺ ions. It takes only [tex]\dfrac{10^{-2}}{2} = 5 \times 10^{-3}\;\text{mol}\cdot\text{dm}^{-3}[/tex] of H₂SO₄ to produce twice as much H⁺ ions.
As a result, the molarity of H₂SO₄ is 5 × 10⁻³ mol / dm³ or 0.005 M.
