Review Chemical Reactions Types of Reactions Controlling Reactions Rates of Reactions Acids and Bases pH level

Review Difference between chemical vs physical change.. Tarnish Melting Glass Breaks Rusting Burning Nail magnetized Sugar dissolving Antacid neutralizes gas

Chemical vs Physical Difference between chemical vs physical change.. Tarnish 2 Ag + S Ag 2 S Melting H2O Glass Breaks SiO 2 Rusting4 Fe + 3 O 2 2 FE 2 O 3 Burning CH O 2 2 H 2 O + CO 2 Nail magnetized Fe Sugar dissolving sugar + water Antacid neutralizes acid Ca(OH) HCl CaCl H 2 O

Chemical Reactions Change in Substance Change of composition New properties Change in Energy Exothermic - releases energy (heat) Endothermic - absorbs energy (heat) A + B C A,B = reactants C = product

Types of Reactions 1) Synthesis A + B AB 4 H + O 2 2 H 2 O 2) Decomposition AB A + B 2H 2 O 2 2 H 2 O + O 2 3) Replacement Single AX + B A + BX 2 Cu 2 O + C 4 Cu + CO 2 Double AB + CD AC + BD FeS + 2 HCl FeCl 2 + H 2 S 4) Oxidation A + O AO + energy CH O 2 2 H 2 O + CO 2 + Heat 5) Neutralization (discussed later)

Controlling Reactions 1) Activation Energy 2) Energy Difference Exothermic Endothermic

Rates of Reactions 1) Temperature 2) Concentration [ ] 3) Catalyst Material which increases rate of reaction by lowering activation energy (not affected by the reaction)

Acids and Bases Acid – donates protons H 1+ Hydrogen ion Sour, burn, corrode, digest, lemon Base – accepts protons (can also be called akaline) OH 1- Hydroxide ion Bitter, slippery, soap, baking soda Neutralization acid + base = water + salt HCl + NaOH H2O + Na + (aq) + Cl - (aq) Measured by pH

Power of Hydrogen p[H] or pH Solution: a liquid with another substance dissolved with in the liquid pH is a measure of the acidity or alkalinity(base) of a solution. It is based on the concentration of dissolved hydrogen ions (H + ). Measured by pH paper or litmus paper Red = acid Blue = base Scale of 1 – 14 pH 1 strong acid pH 14 strong base pH 7 neutral

[H + ]pHExample Acids 1 X HCl 1 x Stomach acid 1 x Lemon juice 1 x Vinegar 1 x Soda 1 x Rainwater 1 x Milk Neutral1 x Pure water Bases 1 x Egg whites 1 x Baking soda 1 x Tums ® antacid 1 x Ammonia 1 x Mineral lime - Ca(OH) 2 1 x Drano ® 1 x NaOH

Nomenclature- 7 Acids and 1 Base Hydrochloric acidHCL Nitric acidHNO 3 Acetic acidHC 2 H 3 O 2 Perchloric acidHClO 4 Carbonic acidHCO 3 Sulfuric acidH 2 SO4 Phosphoric acidH 3 PO 4 AmmoniaNH 3

Describing the Chemical Reaction between Baking Soda and Vinegar Baking soda, a pure chemical called sodium bicarbonate, has the chemical formula: NaHCO 3 When dissolved in water baking soda separates into sodium (Na + ) and bicarbonate ions (HCO 3 - ): NaHCO 3 ---> Na + (aq) + HCO 3 - (aq) Vinegar, a weak (5%) solution of acetic acid in water, partially dissociates into hydrogen ( H + ) and acetate ions (CH 3 COO - ): CH 3 COOH H + (aq) + CH 3 COO - (aq) The reaction between baking soda and vinegar is actually two reactions, an acid base reaction followed by a decomposition reaction. When the two ingredients are mixed, hydrogen ions ( H + ) from the vinegar react with the bicarbonate ions (HCO 3 - ) from the baking soda to form a new chemical called carbonic acid (H 2 CO 3 ). H + + HCO > H 2 CO 3 The carbonic acid thus formed then immediately decomposes into carbon dioxide gas (CO 2 )and water (H 2 O). H 2 CO 3 ---> H 2 O + CO 2 It's this carbon dioxide gas that you see bubbling and foaming as soon as you mix baking soda and vinegar together. Using the molecular structures of only the components involved, the chemical reaction can be written: The overall reaction however, is often written as follows: NaHCO 3 (aq) + CH 3 COOH (aq) ----> CO 2 (g) + H 2 O (l) + CH 3 COONa (aq)

Baking soda and vinegar chemical reaction overview Baking soda and vinegar chemical reaction overview