Ka Formula

Emily Orozco L4
Posts: 22
Joined: Fri Sep 28, 2018 12:29 am

Ka Formula

What do we need to know about the Ka formula? How is it used?

Sydney To 1D
Posts: 60
Joined: Fri Sep 28, 2018 12:15 am

Re: Ka Formula

I would know this formula and how to apply it just in case. $K_{a}= ([H^{^{+}}] [A^{^{-}}])/[HA])$. $pK_{a}=-log_{}1_{0}K_{}a$

Linh Vo 2J
Posts: 61
Joined: Sat Apr 28, 2018 3:00 am

Re: Ka Formula

Ka is the acid ionization constant or equilibrium constant for chemical equations in weak acids with aqueous solutions. You would use the formula to determine the Ka based on the given information given for the molecule. It will not always be H and A, for there are other cases too.

marisaimbroane1J
Posts: 69
Joined: Fri Sep 28, 2018 12:23 am

Re: Ka Formula

You probably need to know that a higher Ka means that the acid is stronger than a lower Ka. This is because the products of a reaction are in the numerator of the Ka equation, so an acid that completely dissociates (strong acid) will have a greater concentration of products than an acid that does not completely dissociate (weak acid).

Kelly Hollman
Posts: 33
Joined: Fri Sep 28, 2018 12:27 am

Re: Ka Formula

Just keep in mind that Ka = Kforward rxn/Kreverse rxn

When you have a higher Ka, then you have more products (e.g., more H+ ions). This increases the pH (more acidic).
Vice versa, when you have a lower Ka, you have more reactants -- there aren't as many H+ ions being produced. This lowers the pH (less acidic).

anishathomas
Posts: 35
Joined: Fri Sep 28, 2018 12:25 am

Re: Ka Formula

You should probably know the formula just to understand that higher concentration in the forward reaction(in products) will lead to a higher Ka, meaning a stronger acid, lower ph.

Aria Soeprono 2F
Posts: 64
Joined: Fri Sep 28, 2018 12:27 am

Re: Ka Formula

An easy way to remember is Ka= [products]/[reactants]