Final answer:
For pH calculations, express the hydrogen-ion concentration as molarity and take its negative logarithm to determine the pH value. To find hydroxide or hydronium concentrations from pH or pOH, use the power of ten corresponding to the negative pH or pOH value.
Step-by-step explanation:
Calculating pH with Hydrogen-Ion Concentration
For pH calculations, you should express the hydrogen-ion concentration in the form of molarity (M), which is moles per liter (mol/L). To calculate the pH value, take the negative logarithm (base 10) of the hydrogen-ion concentration. The result will be a number typically between 0 and 14 on the pH scale, with low values indicating acidity and high values indicating alkalinity.
For example, if you have a solution with a hydrogen-ion concentration of 0.1 M, the calculation steps would be:
- Express the concentration as a power of ten: 0.1 M = 10-1 M.
- Calculate the negative logarithm of the concentration: pH = -log(10-1) = 1. This is the pH of the solution.
Conversely, if you're given a pH and need to find the concentration of hydronium (H3O+) ions, use the inverse process. For a pH of 7.04, the concentration of hydronium ions can be found by calculating 10-pH, resulting in 9.1 × 10-8 M after rounding to two significant figures.
As a reminder, always ensure your calculator can perform these types of calculations, as different models may vary in function and operation.