CALCULATING THE pH OF A WEAK ACID
For acetic acid, CH3COOH, the Ka value is 1.8x10^-5. Calculate the concentration of H+ in a 0.20 M solution.
We were told that the initial concentration of CH3COOH was 0.20 M. Since no initial concentration values were given for H+ and CH3COO-, we assume that none was present. Therefore, we show this by placing a zero in the corresponding cells of the table below.
CH3COOH H+ CH3COO-
Initial Concentration 0.20 M 0 0
Change in Concentration
Since we began without any concentration of H+ and CH3COO-, we know that as CH3COOH ionizes, it will produce some of both of these chemical species. Since we do not know how much of these ...
In this solution I show you step by step (with a total of 6 steps), working out every step in detail, how to calculate the pH of this solution. We start off by filling out a table outlining initial concentrations, changes in concentrations, and final concentrations. Then, we develop a mathematical equation based on these values and the equilibrium expression. Finally, we utilize the quadratic formula to solve the expression and relate that solution to the concentration of H+ that we are looking for.
Calculate the pH
Calculate the pH upon diluting 2ml of 2 N HCL to a final volume of 100 ml?
Calcuate the pH upon addition of 0.0075 mole of solid NaOH to 100 ml of a 0.1 M solution of acetic acid (pKa=4.7)?
If equal molar amounts of Na2HPO4 and NaJpo4 are mixed in water, calcuate the resulting pH. The pKas of phosphoric acid are 2.1, 7.2, 12.4.
Calculate the % dissociation of a 0.1M solution of weak acid(pKa=5.0)?
Which of the following pairs would makw the best buffer at pH10.0?
a. Acetic acid & sodium acetate
b. NaH2PO4 & Na2HPO4
c. H2CO3 & NaHCO3
d. Methylammonium chloride & Methylamine