The Ka for a particular weak acid is 4.0 x 10-9. Calculate the pH of a 0.040 M solution of this acid.
whats the relation b/w Ka and pH?
How do we find [H+]?
You must use Ka to determine the (H^+), then use pH = -log(H^+) to determine pH.
Ka= [A^-][H^+]/[HA]
you have to make an ice table
The Ka value represents the acid dissociation constant, which is a quantitative measure of the strength of an acid in a solution. It describes the extent to which the acid molecules dissociate, or break apart, to form hydrogen ions (H+) and their corresponding conjugate base. In general, a higher Ka value indicates a stronger acid.
The pH of a solution is a measure of its acidity or alkalinity. It is defined as the negative logarithm (base 10) of the concentration of hydrogen ions present in the solution. The pH scale ranges from 0 to 14, with 7 being considered neutral, values below 7 indicating acidity, and values above 7 indicating alkalinity.
There is an inverse relationship between the Ka value and the pH of a weak acid solution. The higher the Ka value, the stronger the acid, and consequently, the lower the pH value.
To calculate the pH of a solution given its Ka value, you typically need to know the concentration of the acid in solution. In this case, the question provides the concentration of the acid as 0.040 M. We can use this information to find the pH.