Biology: Chemistry in Biology: 10: Acids and Bases - Medical Animation
MEDICAL ANIMATION TRANSCRIPT: What are acids and bases? First, recall that water is a polar molecule that dissolves ionic compounds by separating them into negatively-and positively charged ions. An acid is an example of one of these ionic compounds. A sample of this type of substance contains an abundance of positively-charged hydrogen ions that are released from the compound when dissolved in water. A base is also an ionic compound but a sample of this type of substance contains an abundance of negatively-charged hydroxide ions that are released from the compound when dissolved in water. An acid always has a greater concentration of hydrogen ions than hydroxide ions. In contrast, a base always has a greater concentration of hydroxide ions than hydrogen ions. If hydrogen ions and hydroxide ions are present in equal numbers, then the substance is neither an acid nor a base but is neutral like pure water. In summary, an acid is an ionic compound that releases many hydrogen ions when dissolved in water. A base is an ionic compound that releases many hydroxide ions when dissolved in water. Acids have a greater concentration of hydrogen ions than hydroxide ions. Bases have a greater concentration of hydroxide ions than hydrogen ions and neutral substances have equal numbers of hydrogen ions and hydroxide ions.
