Chapter 8.3b

 Neutralization: reaction between an acid and a base  Neutralization reaction produces a salt and water.  Salt  The negative ions in an acid combine with the positive ions in a base to produce an ionic compound called a salt.  Example: HCl + NaOH  [ Cl - + Na + ]  NaCl Acid Base Salt Neutralization and Salts

 Neutralization: reaction between an acid and a base  Neutralization reaction produces a salt and water.  Water  The hydronium ions (H 3 O + ) from the acid combine with the hydroxide ions (OH - ) from the base to produce 2 water molecules (2H 2 O) Neutralization and Salts

 When hydrochloric acid reacts with sodium hydroxide, a neutralization reaction occurs.  Acid in water: HCl + H 2 O  H 3 O + + Cl -  Base in water: NaOH  Na + + OH -  If you let the water evaporate, sodium chloride would crystallize out of solution. Neutralization and Salts

 Table salt is the most common example of a salt compound.  The ocean contains many dissolved salts, including chlorides and sulfates of potassium, calcium, magnesium, and sodium.  Examples: KCl, CaCl 2, MgSO 4, Na 2 SO 4, etc. Neutralization and Salts

Proton Donors and Acceptors  Bronsted-Lowry:  Acids can be defined as proton donors  reminder: a hydrogen nucleus has only 1 proton and no neutrons, so 1 proton is the same thing as a hydrogen nucleus  Bases can be defined as proton acceptors.

 When an acid and a base react in water:  Proton from hydronium ion (from the acid)  Combines with hydroxide ion (from the base)  Two water molecules formed  H 2 O + [H + + OH – ]  Acids lose, or “donate,” protons.  Bases “accept” protons, forming water, a neutral molecule.  2 H 2 O H 3 O + + OH – Proton Donors and Acceptors

 Water is neither an acid nor a base.  Using the proton-donor or proton- acceptor definition:  Water CAN ACT AS either an acid or a base. Proton Donors and Acceptors

When hydrogen chloride dissolves: Proton Donors and Acceptors Water as a BASE

Water accepts a proton from hydrogen chloride and becomes a hydronium ion. H 3 O + & Cl - Proton Donors and Acceptors Water as a BASE

When ammonia dissolves: Proton Donors and Acceptors Water as an ACID

Water donates a proton to the ammonia, which acts as a base. OH - & NH 4 + Proton Donors and Acceptors Water as an ACID

Exit Slip Questions 1. What ion is formed when a base dissolves in water? a) hydroxide ion (OH - ) b) hydronium ion (H 3 O + ) c) hydrogen ion (H + ) d) sodium ion (Na + )

2. What products are formed in a neutralization reaction? a) an acid and a base b) water and a proton c) a base and a salt d) water and a salt Exit Slip Questions

3. Ammonia (NH 3 ) and water react to form an ammonium ion (NH 4 +). Here, water acts as: a) acid because it donates an electron to ammonia. b) base because it donates an electron to ammonia. c) acid because it donates a proton to ammonia. d) base because it donates a proton to ammonia. Exit Slip Questions