However, when dealing with acids and bases, we sometimes find that using moles when working with acids and bases is not the most useful concept. Since the number of moles or equivalents in the original solution solution A is the same as the number of moles or equivalents in the diluted solution solution B , we can write the equation shown. FB Connect. If you know its normality, you will calculate the normality of the diluted solution.

What is an equivalent?

This implies that 9 g of H 2 O was added. If you always remember to include the unit when doing this sort of calculation, you will be unlikely to accidentally divide when you should multiply, or vice versa.

Tonicity - comparing 2 solutions. Sorry about that.

how to calculate number of equivalents

Normality is the number of equivalents of solute per liter of solution. It's negative, right?

Another way to do the same thing is to determine the number of moles: We could say, well, then 1 mole-- now all I did is multiplied both sides by 2-- 1 mole of calcium-- I'm not writing clearly right now, sorry-- 1 mole of calcium equals 2 equivalents.

So it says, "The equivalent is formally defined as the amount of a substance which will either react or supply with one mole of hydrogen ions in an acid base reaction; or do the same with one mole of electrons in a redox reaction. We worked this kind of problem in Lesson 4 when we first learned about molarity. So let's imagine you have a nitrogen here, negative 3, and it's going to be at this, let's say, cocktail party, and it meets some protons.

Opposite of the negative, right?

Units of Concentration (Normality and Equivalent Weight)

So let's do nitrogen. The number of moles you added would be: So I have to draw out a mole, and you know there's no way I can do that, as I said before. Get Free Sample Now.

HCl 36. For a triprotic acid or a tribasic base, the equivalent weight would be one third the molecular weight. They're going to make CaCl2, because the chlorides are only one negative charge-- actually, and this is two positive charges.

Lesson 6: Solutions of Acids & Bases

The number of moles you added would be:. I know that they're talking about some number. It must always be either equal to or some integral fraction of the molecular weight, depending on whether the acid or base has one or more hydrogen or hydroxide ions.

I just needed some negatively charged monovalent, and chloride suits our purposes. How to Calculate Equivalent Units.