Question

What is the pH value of Sulphuric acid?

Answer 1

Part 1: pH

• The pH of any solution is defined as the negative log of Hydrogen ion concentration.
• Mathematically, $\mathrm{pH}=-{\log }_{10}\left[{\mathrm{H}}^{+}\right]$
• pH is used to determine the nature of the solution whether it is acidic, basic, or neutral.

Solution	pH range
Acidic	1 - 6.9
Neutral	7
Basic	7.1 - 14

Part 2: Identifying the pH of the sulphuric acid

• Depending on the values of pH we can further classify the solution as strongly and weakly acidic and basic.
• Sulphuric acid is a strong acid that completely dissociates into its ions to produce hydrogen ions when dissolved in water.
• The dissociation reaction can be represented as:

$\underset{\mathrm{Sulphuric}\mathrm{acid}}{{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)}\to \underset{\mathrm{Hydrogen}\mathrm{ion}}{2{\mathrm{H}}^{+}\left(\mathrm{aq}\right)}+\underset{\mathrm{Sulphate}\mathrm{ion}}{{\mathrm{SO}}_4^{2-}\left(\mathrm{aq}\right)}$

• The pH value of Sulphuric acid lies in the range of approximately 2-3.