I'm not a chemist nor a chemistry student.
I'm trying to understand why the pH of battery acid doesn't match what I expect it to be.
My understanding is that each molecule of sulfuric acid should donate two free hydrogen atoms per molecule of H ₂ SO ₄ .
If I look up the molarity of battery acid, I find that it is about 4.2–5.0 mol/L.
Water doesn't contribute enough hydrogen to worry about, so I should be able to ignore that contribution.
That means there should be about 9 moles of free hydrogen per liter of battery acid.
The formula for pH is -log ₁ ₀ (moles free H+/liter), so I would expect a pH of about -log₁ ₀ (9)= -0.95.
But the pH of battery acid is listed as 0.8, not -0.9.
What am I not getting here?
