Easy chemistry question?

So when you have H2SO4 (96%) does that mean that mean?I learned that H3O+ ions cause acid but what confused me is that when you have 96% H2SO4 acid , does that mean there are a lot of H3O + ions in there because its the strongest one? And if you are reducing % of H2SO4 to lets say 20% , what is hapening there , and why does the acid still dissociate if its alredy dissociated before?


Thank you Chris

1 Answer

  • Chris
    Lv 7
    8 years ago
    Favorite Answer

    Your question is not easy. In fact, I've had to think about it quite a bit.

    When sulfuric acid is listed as 96% pure, that means there is only 4% water (by mass). If you had 100% H₂SO₄, it technically should be called hydrogen sulfate (not sulfuric acid) because there are no hydronium ions present. (In fact, this material used to be (is?) shipped in steel tank cars since there is no hydronium to attack the steel.)

    In a 20% by mass solution of the compound in water, the compound is 100% dissociated.

    If there are only 4 grams of water for every 96 grams of H₂SO₄, I would guess that not all of the compound is able to dissociate since each molecule of compound requires one molecule of water. I think every molecule of water has an added proton, but there are still molecules of H₂SO₄ ready to give up a proton. It seems you have to have about an 85% solution for there to be enough water for 100% dissociation.

    Thank you for asking a question that I had to think about.

Still have questions? Get your answers by asking now.