H+ Concentration from pH

We have learned that the pH is calculated by the following formula: To calculate the concentration of H+ or H3O+ hydronium ion from pH, we take the antilog of the pH, that is 10 to the negative power of pH. … Read more

Calculating the pH of 0.10 M NH4Cl

Ammonium chloride (NH4Cl) is the salt of a weak base ammonia (NH3) and a strong acid HCl, so it yields an acidic solution.   NH3 + HCl → NH4Cl   So, let’s follow what we have discussed earlier and see … Read more

Calculating the Ka for a Weak Acid

Determine the ionization constant (Ka) of a weak acid if its 0.520 M solution has a pH of 2.40. The plan is to determine the [H+] from the pH and use it to determine the equilibrium concentrations of HA and A–. … Read more

Strong Acid–Strong Base Titrations

Earlier in the semester, or perhaps in your Chem II class, you learned about acid-base titrations which were used to determine the concentration of an acid or a base. For this, we are using a standard solution (titrant) which is … Read more

pH Practice Problems

In this set of practice problems, we will work on examples correlating the acidity and basicity of a solution with pH, calculating the pH of strong and weak acids and bases, the pH and pOH relationship, and calculating the pH … Read more

Ka, pKa, Kb, and pKb Relationship

In the previous two posts, we talked about the acid-base strength and their quantitative description using Ka, pKa, Kb ,and pKb. Now, sometimes, we need to do calculations which can be made easier if we find a way to link … Read more

Base Strength, Kb and pKb

Strong Bases The most widely used strong bases in general chemistry are the hydroxides of alkali (group 1A) metals such as KOH (caustic or just potash), NaOH (caustic soda), and LiOH. Just like the strong acids, we recognize them by … Read more

Acid Strength, Ka, and pKa

Acids are classified as strong and weak depending on the extent of their ionization. For example, hydrochloric acid is a strong acid because it completely dissociates in aqueous solutions.   HCl(aq) + H2O(l) → H3O+(aq) + Cl–(aq) or HCl(aq) → … Read more

Buffer Solutions Practice Problems

This is a summary practice problem set on buffer solutions aimed to help identify buffers, calculating the pH of a buffer solution prepared from a weak acid and its conjugate base or vice versa. The links to the corresponding topics … Read more

Acids and Bases Practice Problems

Definition of acids and bases, identifying them along with the conjugate acid and conjugate base, pH of strong and weak acids and bases, the pH and pOH relationship, Ka and Kb, pKa and Ka correlation, the acid-base properties of salts, … Read more