Thursday, 22 September 2016

If a solution of sulfuric acid (H2SO4) has a concentration of 2.1E-4M, what is the concentration of its hydronium ion?

First, let's look at this question using 2.1 x M HCl instead of . HCl is a strong acid. This means that it will disassociate completely in water: 


    + -> +


Therefore, all of the hydrogen ions in HCl will be converted into hydronium ions ( ). Since there is a 1:1 ratio of HCl used and produced, the concentration of HCl and the concentration of ...

First, let's look at this question using 2.1 x M HCl instead of . HCl is a strong acid. This means that it will disassociate completely in water: 


    + -> +


Therefore, all of the hydrogen ions in HCl will be converted into hydronium ions ( ). Since there is a 1:1 ratio of HCl used and produced, the concentration of HCl and the concentration of will be the same, 2.1 x M.


Now, let's look at what happens when we use 2.1 x is also a strong acid and will disassociate completely in water; however,  has two H atoms instead of just one. This means that we will need to react two molecules of with every one molecule of  :


     -> +


Since this reaction results in the production of two molecules for every one molecules, the concentration of hydronium ions ( ) will be twice the concentration of the .


   2  x (2.1 x M) = 4.2 x M .

No comments:

Post a Comment

How can a 0.5 molal solution be less concentrated than a 0.5 molar solution?

The answer lies in the units being used. "Molar" refers to molarity, a unit of measurement that describes how many moles of a solu...