Presentation on theme: "Chapter 25 Acids, Bases, and Salts Section 1-Acids and Bases."— Presentation transcript:
Chapter 25 Acids, Bases, and Salts Section 1-Acids and Bases
Properties of Acids An acid is a substance that produces hydrogen ions in a water solution. The ability to produce ions is what gives their characteristic properties. When an acid dissolves in water, H ⁺ ions interact with water molecules to form H ₃ 0 ⁺ ions, which are called hydronium ions.
Common Acids Citric Acid is found in citrus fruits. Lactic Acid is found in yogurt and buttermilk. Vinegar is also known as acetic acid. Your stomach uses hydrochloric acid to help you digest your food.
Common Acids Name, FormulaUseOther Information Acetic AcidFood Prep and PreservationWhen in solution with water it is known as vinegar Acetylsalicyclic AcidPain Reliever, Fever reducerKnown as aspirin Ascorbic AcidAntioxidant, VitaminCalled Vitamin C Carbonic AcidCarbonated DrinksInvolved in cave, stalactite, and stalagmite formation and acid rain Hydrochloric AcidDigestion as gastric juiceCommonly called Mariatic Acid Phosphoric AcidMakes detergents, fertilizers, and soft drinks Sour but pleasant taste, detergents containing phosphates polute water Sulfuric AcidCar batteries, fertilizersDehydrating agent, causes burns by removing water from cells Nitric AcidMakes fertilizersColorless, but yellow when exposed to light
Properties of Bases A substance that forms hydroxide ions, OH ⁻, in a water solution is a base. A base is also any solution that accepts H ⁺ from acids. Think of bases as the opposite of acids.
Properties of Bases In pure and undissolved state many bases are crystalline solids. In a solution bases feel slippery and have a bitter taste. Strong bases are like strong acids as they are corrosive and can burn the skin.
Common Bases Name, FormulaUseOther information Aluminum HydroxideColor-fast fabrics, antacid, water purification Sticky gel that collects clay ad dirt particles on surface Calcium HydroxideLeather-making, mortar and plaster, lessen acidity of soil Called caustic lime Magnesium HydroxideLaxative, antacidCalled milk of magnesia Sodium HydroxideTo make soap, oven cleaner, drain cleaner, textiles, and paper Called lye and caustic soda; generates heat when combined with water, reacts with metals to form hydrogen AmmoniaCleaners, fertilizer, to make rayon and nylon Irritating odor that is damaging to nasal passages and lungs
Acids & Bases Ammonia is a popular household cleaner. Never combine products containing ammonia with other cleaners that contain chlorine such as toilet bowl cleaners and bleach. The reaction produces poisonous gases. Solutions of both acids and based produce some ions that are capable of carrying electric current to some extent. They are considered to be conductors.
Chapter 25 Acids, Bases, and Salts Section 2- Strengths of Acids and Bases
Strong Acids and Weak Bases The strength of an acid or base depends on how completely a compound separates into ions when dissolved in water. An Acid that ionizes almost completely in solution is a Strong Acid. ex. Hydrochloric Acid A weak acid is an acid that only partly ionizes in a solution. Ex. Acetic and Carbonic Acids
pH The pH of a solution is a measure of the concentration of H ⁺ ions in it. The greater the H ⁺ concentration is, the lower the pH is and the more acidic the solution is. The pH measures how acid or basic a solution is.
pH To indicate pH, a scale ranging from 0 to 14 has been devised.
pH Solutions with a pH lower than 7 are described as acidic. Solutions with a pH greater than 7 are described as basic. A pH of exactly 7 indicates that the concentration of H ⁺ ions and OH ⁻ ions are equal. These solutions are neutral. Ex. Pure water at 25 degrees has a pH of 7.
pH One way to determine pH is by using pH indicator strips. The final color of the pH paper is matched with colors on a chart to find the pH.
Blood pH The blood that circulates through your body has a pH of between 7.0 and 7.8 Your body can not work outside of this pH range. Does your Blood pH change when you eat spicy/acidic foods?
Blood pH You would think that your pH in your blood changes when you eat spicy/acidic foods but it does not. Your blood contains compounds called Buffers that enable small amounts of acids or bases to absorbed. Buffers are solution containing ions that react with additional acids or bases to minimize their effects on pH.
Chapter 25 Acids, Bases, and Salts Section 3-Salts
Neutralization Neutralization is a chemical reaction between an acid and a base that takes place in a water solution. Antacid Tablets are an example of a product that a person suffering from indigestion cant take to “neutralize” the effects of acid reflux.
A salt is a compound formed when the negative ions from an acid combine with the positive ions from a base. NameCommon NameUses Sodium ChlorideSaltFood Prep Sodium Hydrogen Carbonate Sodium bicarbonate baking soda Food Prep and antacids Calcium CarbonateCalcite, ChalkMaking paint and tires Potassium NitrateSaltpeterFertilizers Potassium CarbontePotashMaking soap and glass Sodium PhosphateTSPDetergents Ammonium ChlorideSal ammoniacDry-Cell Batteries
Titration If you need to know the concentration of an acid or base in a solution you can determine it through a process called titration.