Question

If and acid has a Ka dissociation constant of 1 x 10-9 what is the pKa of this acid?

Answer 1

Answer:

pKa = 9

Explanation:

In this case, we have to remember the meaning of "p". When we use "p" in any calculation we have to apply the minus ten based logarithm, so:

$p~=~-Log$

For example, when we use the "pH" value. We have to apply the minus ten based logarithm of the concentration of the hydronium ion:

$pH~=~-Log[H^+]$

So, if we have wanted to calculate the pKa value. We have to apply the minus ten based logarithm of the Ka value, so:

$pKa~=~-Log~Ka$

Now we can plug the value into the equation:

$pKa~=~-Log~1x10^-^9$

$pKa~=~9$

The pKa value is 9.

I hope it helps!