Final answer:
Products are classified as alkaline or acidic based on the concentration of H+ ions. Acids have a higher concentration of H+ ions, which results in a lower pH, while bases have a higher concentration of hydroxide ions, leading to a higher pH. The pH scale is used to quantify this acidity or alkalinity.
Step-by-step explanation:
Products are classified as either an alkaline solution or an acidic solution by measuring the amount of H+ ions. This is because acids are substances that provide hydrogen ions (H+) and lower pH, while bases provide hydroxide ions (OH-) and raise pH. The pH scale measures the acidity or alkalinity of a substance, where a pH below 7 is acidic (more H+ ions) and a pH above 7 is alkaline (more OH- ions).
A solution is considered acidic if the concentration of hydronium ions [H3O+] is greater than 1 × 10-7 M, basic if [H3O+] is less than 1 × 10-7 M, and neutral if [H3O+] equals 1 × 10-7 M. We measure these hydronium ions because they represent the presence of hydrogen ions in a solution, and their relative concentration directly impacts whether a solution is acidic or basic.