They are everywhere.. In your food In your house EVEN IN YOU!!!!! Acids & Bases They are everywhere.. In your food In your house EVEN IN YOU!!!!! Dr Seemal Jelani 8/25/2018

What is an acid? An acid is a solution that has an excess of H+ ions. It comes from the Latin word acidus that means "sharp" or "sour". The more H + ions, the more acidic the solution. Dr Seemal Jelani 8/25/2018

Properties of an Acid Tastes Sour Conduct Electricity Corrosive, which means they break down certain substances Many acids can corrode fabric, skin, and paper Dr Seemal Jelani 8/25/2018

Introduction to Acids (con’t) Lactic acid is also produced by bacteria in milk – this is why milk turns sour. Acids occur naturally in many fruits. Insects such as millipedes, scorpions, and ants use acids to deter predators. A physician may use a solution of boric acid to rinse out your eyes, but a drop or two of many other acids would blind you. Some acids add a tangy, sour flavour to foods and drinks, while others are deadly.

Some acids react strongly with metals Turns blue litmus paper red Dr Seemal Jelani 8/25/2018

Definitions Lewis Acids – produce H+ Bases - produce OH- Acids – donate H+ Bases – accept H+ Acids – accept e- pair Bases – donate e- pair Arrehenius only in water Bronsted-Lowry any solvent Lewis used in organic chemistry, wider range of substances Dr Seemal Jelani 8/25/2018

Examples Arrhenius Bronsted-Lowry Lewis :NH3 The hydrogen ion in aqueous solution H+ + H2O  H3O+ (hydronium ion) Examples Arrhenius HCl NaOH Bronsted-Lowry HCl HCN NH3 Lewis BF3 :NH3 Dr Seemal Jelani 8/25/2018

Word Connect The word “acid” comes from the Latin acidus, meaning “sour” Think of the taste of fruits such as lemons or limes These fruits contain citric acid Vinegar, a common household product, contains acetic acid.

This word shows the Arabic origin of chemistry Chemists sometimes use the term “alkali” for a base that is soluble in water This word shows the Arabic origin of chemistry The earliest source of bases was the ash obtained by burning plants Thus the Arabic word alkali means “ashes of a plant.” Dr Seemal Jelani 8/25/2018

Uses of Acids Acetic Acid = Vinegar Citric Acid = lemons, limes, & oranges. It is in many sour candies such as lemonhead & sour patch. Dr Seemal Jelani 8/25/2018

Ascorbic acid = Vitamin C which your body needs to function. Sulfuric acid is used in the production of fertilizers, steel, paints, and plastics. Car batteries Dr Seemal Jelani 8/25/2018

What is a base? A base is a solution that has an excess of OH- ions. Another word for base is alkali. Bases are substances that can accept hydrogen ions Dr Seemal Jelani 8/25/2018

Bases are bitter-tasting compounds with a slippery feel. Most soaps and drain and window cleaners are bases.

Properties of a Base Feel Slippery Taste Bitter Corrosive Can conduct electricity. (Think alkaline batteries.) Do not react with metals. Turns red litmus paper blue. Dr Seemal Jelani 8/25/2018

Uses of Bases Bases give soaps, ammonia, and many other cleaning products some of their useful properties. Dr Seemal Jelani 8/25/2018

Your blood is a basic solution. The OH- ions interact strongly with certain substances, such as dirt and grease. Chalk and oven cleaner are examples of familiar products that contain bases. Your blood is a basic solution. Dr Seemal Jelani 8/25/2018

Defining Indicators Two of the most common indicators are phenolphthalein and litmus. Litmus is a compound that is extracted from lichens, a plant-like member of the fungi kingdom Litmus paper is made by dipping paper in litmus solution.

The Oxides of Elements Oxides of many elements react with water to form an acid or a base. An oxide is a compound that consists of an element combined with only oxygen For example, CO (carbon monoxide), CO2 (carbon dioxide), and Al2O3 (aluminum oxide) are oxides. H2SO4 and HNO3 are not.

pH Scale pH is a measure of how acidic or basic a solution is. The pH scale ranges from 0 to 14. Acidic solutions have pH values below 7 A solution with a pH of 0 is very acidic. A solution with a pH of 7 is neutral. Pure water has a pH of 7. Basic solutions have pH values above 7. Dr Seemal Jelani 8/25/2018

Acid – Base Reactions A reaction between an acid and a base is called neutralization. An acid-base mixture is not as acidic or basic as the individual starting solutions. Dr Seemal Jelani 8/25/2018

Acid – Base reactions Each salt listed in this table can be formed by the reaction between an acid and a base. Dr Seemal Jelani 8/25/2018

General properties ACIDS Taste sour Turn litmus React with active metals – Fe, Zn React with bases BASES Taste bitter Turn litmus Feel soapy or slippery (react with fats to make soap) React with acids Dr Seemal Jelani 8/25/2018 blue to red red to blue

Neutralization In general: Acid + Base  Salt + Water All neutralization reactions are double displacement reactions. HCl + NaOH  NaCl + HOH HCl + Mg(OH)2  H2SO4 + NaHCO3  Dr Seemal Jelani 8/25/2018

Strong and Weak Acids/Bases Strong acids/bases – 100% dissociation into ions HCl NaOH HNO3 KOH H2SO4 Weak acids/bases – partial dissociation, both ions and molecules CH3COOH NH3 Dr Seemal Jelani 8/25/2018

When life goes either way amphoteric (amphiprotic) substances Acting like a base Acting like an acid HCO3- + H+ - H+ H2CO3 CO3-2 accepts H+ donates H+ Dr Seemal Jelani 8/25/2018