Ok I know equivalence point is when amount of base or acid added is equal to amount of acid or base present. Does "amount" just mean volume of acid or base added = volume of acid or base present, or is it in moles??
2007-07-23 15:53:53 · 5 answers · asked by victoria 5 in Science & Mathematics ➔ Chemistry
OK, so to do THIS problem:
How much of .135 M HCl is added to 55.5 mL of .234 M NH3 to reach the equivalence point?
I just find moles NH3, which is equal to moles of HCl, and then convert from moles HCl to volume HCl using concentration?
2007-07-23 16:01:39 · update #1
Yup, the amount means the number of moles needed to neutralize the acid or base. So, if you have the known concentration, you can divide the number of moles with this value to get the required volume.
In your problem, if you get 96.2 mL as the answer, then you are on the right track.
2007-07-23 16:27:14 · answer #1 · answered by titanium007 4 · 0⤊ 0⤋
Amount of moles or equivalents are equal. If both the acid and the base have only one ionizable hydrogen (for the acid) or hydroxide (for the base) then the equivalence point is where the moles are equal.
Liters x Molarity = Moles (since Molarity = Moles per Liter)
mL x M = millimoles.
Two equations you will use are-
L x M = L x M
L x M = grams/molecular weight (moles)
If you have an acid like H2SO4, then the equivalent weight is 1/2 of the molecular weight so the normality (N) = 2 x Molarity.
2007-07-23 23:06:43 · answer #2 · answered by skipper 7 · 0⤊ 0⤋
Its in moles, equivalence point means that the amount in moles of acid or base added has already neutralized the amount of acid or base present. if we simply know the volume then we wouldnt be using phenolpthalein indicators now hehe.
2007-07-23 22:59:22 · answer #3 · answered by supermontero2000 2 · 0⤊ 0⤋
You're singing our song. Great work.
2007-07-23 23:06:40 · answer #4 · answered by cattbarf 7 · 0⤊ 0⤋
mass, not volume.
2007-07-23 22:58:30 · answer #5 · answered by Anonymous · 0⤊ 0⤋