Using Kb

[Ashley Hiti 1K]

Can you use Ka and Kb in the same ways when solving problems?

[Michelle Zhang 1J]

The way you use Ka and Kb is the same. They are both equilibrium constants. Note that Ka is the equilibrium constant of an acid, and Kb is the equilibrium constant of a base. So for acid HA, the reaction in water is HA + H2O <--> A- + H3O+, and Ka = [A-][H3O+]/[HA]. And for base B, the reaction in water is B + H2O <--> BH+ + OH-, and Kb = [BH+][OH-]/[B].

If HA and B are conjugate acid base pairs though, Ka x Kb = 1.0 x 10^-14 = Kw.

[Mia Hansen 2I]

you use kb and ka the same way, but you may have to covert between kb and ka in a problem. for example, if you were given kb but the reaction involves an acid, you need the ka value.

[Fiona H 2E]

As said above, you use them essentially the same way, so you can think of it as the same concept except Ka pertains to an Acid and Kb pertains to a base.

[Ivy Nguyen 3I]

Yes! Ka and Kb are used in the same way but you must make sure that which one you are using corresponds to the problem. If pH or pOH given indicate that you are dealing with a weak acid, always make sure to use Ka and vice verse. Many times problems may try to trick oyu by giving you the opposite equilibrium constant necessary for solving so you definitely don't want to miss that!

[Kayla Arellano 1K]

Can you use Ka and Kb in the same ways when solving problems?

We use Ka when the chemical equations consists of reactants of an acid and water and products of its conjugate base and H3O+. We use Kb when the chemical equation reaction consists of reactants of a base and water and products of its conjugate acid and OH-.

[Erin Chin 1L]

Ka and Kb are both equilibrium constants, so they are used in essentially the same way. However, just know that that Ka is used when dealing with acids, while Kb is used when dealing with bases. You would solve for them using [P]/[R]. If given one of them (Ka or Kb), you can always solve for the other one by using the equation (Ka)(Kb)= 1.0 x 10^-14 (Kw).

[Emily Wan 1l]

Kb and Ka are related through the equation Kb * Ka = Kw = 1*10^-14. They both measure the ratio of products and reactants in an equation ; Ka is used when the reactant involves an acid, while Kb is used when the reactant involves a base.