Enough of a monoprotic acid is dissolved in water to produce a 0.0190 M solution. The pH of the resulting solution is 2.33. Calculate the Ka for the acid.
pH = -log (H^+)
2.33 = -log(H^+)
(H^+) = about 0.005 which is only an estimate.
..........HA ==> H^+ + A^-
I......0.0190....0......0
C.......-x.......x......x
E...0.0190-x.....x......x
Ka = (H^+)(A^-)/(HA)
You know the value of x, substitute those values into the Ka expression and solve for Ka.
I know how to do the ice chart and set up i just don't know how to get the x value that you are saying that i know...
To calculate the Ka (acid dissociation constant) for the monoprotic acid, we need to use the pH of the resulting solution. The Ka is a measure of the strength of an acid.
Step 1: Write the balanced equation for the dissociation of the acid.
For a monoprotic acid, it typically dissociates into a hydrogen ion (H+) and the conjugate base when dissolved in water. Let's represent the acid as HA.
The dissociation reaction can be written as:
HA (aq) ⇌ H+ (aq) + A- (aq)
Step 2: Write the expression for the acid dissociation constant (Ka).
The Ka expression represents the ratio of the concentration of the products (H+ and A-) to the concentration of the reactant (HA).
Ka = [H+][A-] / [HA]
Step 3: Identify the initial and equilibrium concentrations.
The initial concentration of HA can be determined from the given molarity of the solution. In this case, it is given as 0.0190 M.
Since we know that the pH is 2.33, we can convert this to the concentration of H+ ions. The pH is defined as the negative logarithm (base 10) of the H+ concentration.
pH = -log[H+]
H+ = 10^(-pH)
Step 4: Substitute the concentrations into the Ka expression and solve for Ka.
The expression becomes:
Ka = ([H+][A-]) / [HA]
Ka = (10^(-pH)[A-]) / [HA]
Now, let's substitute the given values into the equation:
Ka = (10^(-2.33)[A-]) / 0.0190
To calculate the Ka, we need the concentration of the conjugate base (A-). However, without additional information, we cannot determine its concentration.
Therefore, we cannot calculate the Ka for the acid with the given information.
If you have additional information, such as the initial concentration of the conjugate base, please provide it so that we can complete the calculation.