1 / 38

Chemical Reactions and Acids/Bases

Chemical Reactions and Acids/Bases. Physical Science. Chemical Reactions. When 2 or more elements chemically combine to form a “ new ” substance. Chemical Equation. Is a representation of a chemical reaction Two Parts Reactants Products. Reactants vs Products. C + O 2  CO 2

satinka-herrera
Télécharger la présentation

Chemical Reactions and Acids/Bases

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chemical Reactions and Acids/Bases Physical Science

  2. Chemical Reactions • When 2 or more elements chemically combine to form a “new” substance

  3. Chemical Equation • Is a representation of a chemical reaction • Two Parts • Reactants • Products

  4. Reactants vs Products C + O2 CO2 The arrow () divides an equation in half Products The new substance(s) that form All things on the right side of the “” Ex: CO2 • Reactants • The substance(s) that undergo the change • All things on the left side of the “” • Ex: C & O2

  5. Id the Reactants and Products • 2Cu + O2 2CuO • 2KClO3  2KCl + 3O2 • HCl + NaOH  NaCl + H2O • N2H4 + O2  N2 + 2H2O

  6. Endothermic vs Exothermic • Endothermic • Reaction absorbs energy from its surrounding • Surrounding becomes warmer • Exothermic • Reaction releases energy to the surrounding • Surrounding becomes warmer

  7. Signs of a Reaction • Production of a GAS • Fizzing, bubbling • Formation of a Precipitate • Insoluble solid • Energy is released • Light, heat • Color Change

  8. Counting Atoms • Number in front is called a coefficient • Coefficients are multiplied to all elements behind it • Subscripts go to what they just follow

  9. Counting Atoms Practice • 2CO2 • Mg(OH)2 • 3Ca(NO3)2 • NH4OH

  10. How Do I Balance an Equation? • Id the elements present • Count the amount of atoms on both sides of the “” for each element • Place coefficients in front of compounds and multiply to any subscript • Recount the atoms to see if they are equal

  11. Balancing Practice #1 ____Cu + ____O2 ____CuO

  12. Balancing Practice #2 ____N2H4 + ____O2 ____N2 + ____H2O

  13. Balancing Practice #3 ____KClO3 ____KCl + ____O2

  14. Why Balance? • The Law of Conservation of Matter • Matter is neither created nor destroyed • Start = Finish

  15. Types of Reactions • 4 Main Types • Synthesis • Decomposition • Single Replacement • Double Replacement • 2 Special Types • Combustion Reaction • Neutralization Reaction

  16. Synthesis ReactionA + B  AB • When 2 or more substances react to form a single substance • 21 • Dating: Becoming a Couple

  17. Decomposition ReactionAB  A + B • When a compound breaks down into two or more substances • 12 • Dating: Breaking Up

  18. Single Replacement ReactionA + BC  B + AC • A reaction in which one element trades places with another element in a compound • Element and Compound  Element and Compound • Dating: CHEATING

  19. Double Replacement ReactionAB + CD  AD + BD • Where two different compounds exchange positive ions (cations) to form two new compounds • All compounds • (4 of them) • Dating: Swingers

  20. Type Of Reaction Practice • Na3PO4 + 3KOH  3NaOH + K3PO4 • P4 + 3O2  2P2O3 • Pb + FeSO4  PbSO4 + Fe • CaCO3  CaO + CO2

  21. Special Reaction: Combustion Reaction • When a hydrocarbon (hydrogen and carbon together) reacts with Oxygen • Products are always CO2 & H2O • Ex: CH4 + 2O2 CO2 + H2O

  22. Acids • Compounds that produces hydronium (H+) ions when dissolved in water • Formula start with “H”

  23. Acid Properties • Sour Taste • Reacts violently with metals • Electrolyte • Burns the skin

  24. Common Acids • Hydrochloric Acid—HCl • Sulfuric Acid—H2SO4 • Nitric Acid—HNO3 • Citric Acid—C6H8O7 • Acetic Acid—CH3COOH

  25. Bases • Compound that produces hydroxide (OH--) ions when dissolved in water • Formula ends in “OH”

  26. Base Properties • Bitter Taste • Slippery Feel • Will burn the skin

  27. Common Bases • Calcium Hydroxide—Ca(OH)2 • Magnesium Hydroxide—Mg(OH)2 • Sodium Hydroxide--NaOH

  28. How to Determine If A Compound is an Acid or Base? • ACID’s Formula starts with “H” • BASE’s Formula end in “OH” • If it does neither then it is a SALT

  29. Acid, Base or Salt? • LiOH • HCl • NaCl • NH4OH • Ca3(PO4)2 • H2SO4

  30. Special Reaction:Neutralization Reaction • When a reaction between an ACID and a BASE produced A SALT and WATER • A Double Replacement Reaction HCl + NaOH NaCl + H2O

  31. pH Scale • Used to determine how acidic or basic something is • From 0—14 (number line) • Acid Range: 0—6 • Strong Acid: 0—2 • Base Range: 8—14 • Strong Base: 10—14 • Water has a pH of 7 (neutral)

  32. Indicators • Blue Litmus Paper • Acid—turns Red • Base—no change • Red Litmus Paper • Acid—no change • Base—turns Blue

  33. Indicators • pHPaper • Acid—turns red, orange, yellow tints • Base—turns blue-green to dark blue tints • Phenolphthalein • Acid—stays clear • Base—turns hot pink

More Related