equivalents are used to measure individual ion amount present in body fluids, an intravenous solutions here, we're going to say that an equivalent or abbreviated E Q. Is the number of moles of charge, That one I'll contributes to a solution. I want to say here that an equivalent equals one mole of positive or negative charge. One important thing to remember is that an equivalent can only be a positive value though. So for example, here we have one mole of sodium ion. The charge is Plus one. So we'd say we have one equivalent here, we say one mole of iron three I on the number of the charges, three, which equates to three equivalents of iron three ion. We'll see how to calculate that right below. We're gonna say to calculate the number of equivalent of an ion, we simply multiply ion charge for the number of moles of ion present. Here, we're going to say that a milli equivalent is a common unit used to express equivalents. And remember millie, so one equivalent equals 1000 milli equivalents. And when it comes to an equivalent, just remember, equivalent equals ion charge times the moles of ions. So if we went up above again, the charge here is one and the number of moles is one. So that's why I was one equivalent here. The mole, the ion charges three and it's just one mole of iron three ion. So that's why the equivalent was three. So just keep that in mind when asked to calculate the equivalent of any ionic solution.

Now that we've looked at equivalence, we can talk about normality. Non normality is the concentration of ions in Equus solution. And we're going to say that normality, which uses the variable capital N, represents the number of equivalence per liter of solution. Right? So just remember we've calculated equivalents before what's equal to the ion charge times the moles of ions. Now we're going to incorporate that understanding into this idea of normality, normality equals equivalents over leaders of solution.