Presentation on theme: "The pH Scale Is a substance an acid or a base?. ACIDS AAAAn acid is a compound that increases the number of hydrogen ions when dissolved in water."— Presentation transcript:
ACIDS AAAAn acid is a compound that increases the number of hydrogen ions when dissolved in water (H+) AAAAn acid solution tastes sour AAAAn acid can change the color of certain compounds
What is an ion? **An ion is an atom that has lost or gained an electron giving it a positive (+) or negative (-) charge. ** Charged Atom
USES OF ACIDS Citric acid and ascorbic acid (Vitamin C) are found in orange juice Carbonic acid and phosphoric acid give a “bite” to soft drinks Acids in your stomach aid in digestion Sulfuric acid is the most widely used industrial acid in the world. It is used in making metals, paper, paints, and fertilizers.
BASES A base is any compound that increases the number of hydroxide ions (OH-) when mixed with water A base solution tastes bitter A base solution feels slippery A base can change the color of certain compounds
Uses of Bases Bases are used in soaps (remember, bases are slippery) Bases are used to make paper, in oven cleaners, and to unclog drains Ammonia is a base and is used in many household cleaners
Detecting Acids and Bases You can detect an acid using an indicator. INDICATOR - A substance that changes color in the presence of an acid or a base.
INDICATORS Litmus paper is an indicator An acid turns blue litmus paper red A base turns red litmus paper blue
pH of Common Substances Timberlake, Chemistry 7 th Edition, page 335
Did we Miss something?? What happens when the pH of a substance is 7? Ans: A pH level of 7 indicates a Neutral Substance i.e: Water!
Why Learn about pH? What do you think is the pH level of NYC tap water? The pH of a swimming pool must be checked periodically. Why? Is it important for Lakes & Rivers to maintain a certain pH?
How do Antacids Work? Normal pH in your stomach is 3 If your stomach pH drops below 3 you don’t feel so well An antacid neutralizes the acid in your stomach and brings the pH up to a 3 or 4
Antacids A base can't neutralize your acid all by itself. A base needs some chemical "helpers” All antacids contain at least one of these four primary ingredients: * Sodium * Calcium * Magnesium * Aluminum.