Acids and Bases - BookB PDF

Acids & Bases – BookB  Acids: 1. Turn blue litmus red 2. React with metals to form hydrogen 3. Are corrosive 4. Have a pH < 7 Common lab acids include: 5. Hydrochloric acid  HCl 6. Sulfuric acid  H2SO4 Common household acids:  7. Vinegar  ethanoic acid 8. Lemon  citric acid Bases: 1. 2. 3. 4....

Acids & Bases – BookB  Acids: 1. Turn blue litmus red 2. React with metals to form hydrogen 3. Are corrosive 4. Have a pH < 7 Common lab acids include: 5. Hydrochloric acid  HCl 6. Sulfuric acid  H2SO4 Common household acids:  7. Vinegar  ethanoic acid 8. Lemon  citric acid Bases: 1. 2. 3. 4. Turn red litmus blue Neutralise acids Are corrosive Have a pH > 7 Common lab bases: Sodium hydroxide  NaOH Sodium carbonate  Na2CO3 Ammonia  NH3  An alkali is a base that dissolves in water  Neutralisation - An acid and a base react to form a neutral solution of salt and water. Summary of Arrhenius Theory  An Arrhenius acid is a substance that dissociates in aqueous solution, forming hydrogen ions.  An Arrhenius base is a substance that dissociates in aqueous solution forming hydroxide ions.  monobasic acids they donate one H+ ion.  dibasic acid donates two H+ ions. EVIDENCE:  Explains why strong acids only conduct electricity in water.  Explains why weak acids & bases are poor conductors.  Explains why acids usually need water before they can show their acidic properties. LIMITATIONS:  It is limited to reactions that take place in water.  It does not explain how certain substances can be amphoteric (ie. Act as both an acid & a base).  Arrhenius did not take account of the formation of a hydronium ion when an acid dissociated in solution  The H3O+ ion is called the hydronium ion  Bronsted Lowry – Theory An acid is a proton donor A base is a proton acceptor.  Amphoteric - An amphoteric substance is one that can act as either an acid or a base Conjugate Acid-Base Pairs - These are species which di er by the presence or absence of a proton.  An acid changes into its conjugate base when it donates a proton  A base turns into its conjugate acid when it accepts a proton  The stronger an acid, the weaker it's conjugate base.  The stronger a base, the weaker it's conjugate acid. Acid base c. acid c.base HNO₃ + H₂O ⇋ H₃O⁺ + NO₃⁻