What Is "Gram-Equivalent"?

Next Video:
What Is Incoming Shortwave Radiation?....5

Gram equivalent is honestly a little bit outdated. Find out more about the term gram equivalent with help from a chemistry professional in this free video clip.

Part of the Video Series: Chemistry Questions
Promoted By Zergnet


Video Transcript

Hi, I'm Robin Higgins, and this is "what is Gram-Equivalent?" Okay, so gram equivalent is honestly a little bit outdated. It's not used that much anymore. Molar mass has really replaced it, but what it means is it's the amount of a substance needed to react with or supply either one mole of hydrogen ions or one mole electrons. So, what does that mean? Okay, well, let's take sulfuric acid, which has chemical formula H2SO4. Now, when sulfuric acid completely dissociates, it forms two positively charged hydrogen ions and one sulfate ion that's two minus charged. Okay, so this means that for every mole of sulfuric acid, you actually get two moles of hydrogen ions. So, what you do is you take the atomic weight of sulfuric acid, which is 98 point oh eight grams per mole, and since you're getting two moles, you divide it by two, and so that equals 49 point oh four, and the units are grams over equivs, or equivalents. And, so, what this means is that you only need half as much sulfuric acid as you would, say, hydrochloric acid, if you need to react something with an asset. And, so, it doesn't always change the number, like if you take sodium hydroxide, a base, so remember, it's either react with or supply one mole of hydrogen ions. So, in sulfuric acid's case, it supplied the ions. In sodium hydroxide's case, it's going to react with the ions. So, this is gonna disassociate into positively charged sodium and negatively charged hydroxide, each having a charge of one, and so you can see this is going to have a one to one ratio. So, the molar mass of sodium hydroxide is about 40 grams per mole, and that's how much you're gonna need to react with one mole of hydrogen ions. So, the gram equivalent is just gonna be 40 grams per equiv. So, all you need to do is to find out how many moles of your substance you need to react with to find, to have one of these two things met, and you'll have found your gram equivalent. I'm Robin Higgins and this is "what is gram equivalent?"


Related Searches

Is DIY in your DNA? Become part of our maker community.
Submit Your Work!