Presentation on theme: "Acids, Bases and Salts Acid-Base Theories"— Presentation transcript:
1Acids, Bases and Salts Acid-Base Theories CHAPTER 15PA
2What is an Acid?The term acid comes from the Latin term acere, which means "sour".ex. Lemon juice, vinegar, and many other foods taste sour.
3Acids Bases Taste sour Corrosive React with some metals to produce H2 Change Litmus to red acid= redReact with bases to form water and salt.Bases taste bitterFeel slipperyCorrosiveChange Litmus to blue base = BlueBecome less basic when mixed with acids.
5Table L Common Bases Formula Name NaOH(aq) sodium hydroxide KOH(aq) potassium hydroxideCa(OH)2(aq) calcium hydroxideNH3(aq) aqueous ammonia
6Svante ArrheniusSwedish chemist, proposed theories of electrolytic disassociation (acids/bases) and greenhouse effect.
7Arrhenius Theory of Acids & Bases Acid - produces hydrogen ion (H+) in a solution.HA H+ + A¯Base – produces hydroxide ion (OH¯) in a solution.XOH X+ + OH¯
8Nature of the Hydrogen Ion or Proton Proton is so small that does not exist isolated in water.H+ + H2O H3O +Hydronium Ion
9Nature of Hydroxide Ion The presence of OH- makes the substance an electrolyte and a base.Alcohols contain the OH group but are NOT IONIC COMPOUNDS therefore alcohols are NOT bases.C H O are molecular compounds NOT ionic compounds!!!!
10HOW TO NAME ACIDS OUS if ion ends ITE IC if ion ends in ATE NO OXYGEN IN FORMULAHYDRO ACIDHCl Hydrochloric acidHBr Hydrobromic acidHF Hydrofluoric acidH2S Hydrosulfuric acidOXOA CIDSCONTAIN OXIGEN IN FORMULAENDINGOUS if ion ends ITEIC if ion ends in ATEUse table E
11Solutions of Ionic Compounds conduct electricity = Electrolytes Electrolytes – ions (charged particles) in solution.HCl(aq) H+ + Cl-HydrochloricAcidH+Cl -
12Solutions Electrolytes – conduct electricity when dissolved in H2O ; Release OH- (aq)Metal (+) and Non-Metal (-)
19Binary Acids - composed of hydrogen + 1 other element Ex Binary Acids - composed of hydrogen + 1 other element Ex. HCl Hydrochloric Acid Binary Acids begin with “hydro -” followed by name of other element; modified with an ending of “-ic”
20Ternary Acids - molecular (covalent) - composed of hydrogen + Ternary Acids - molecular (covalent) - composed of hydrogen + oxygen containing polyatomic ion (Ref. E) Ex. HNO3 Nitric Acid (NO31- Nitrate ion) HNO2 Nitrous Acid (NO21- Nitrite ion) H2SO4 Sulfuric Acid (SO42- Sulfate ion) Ternary Acids = Anion suffix (-ate or -ite) is dropped and replaced with “-ic” or “-ous” respectively.
22Common Acids – Ref. K Nitric acid (HNO3) Hydrochloric acid (HCl) 1) Most is used to make fertilizer2) Well known for making explosivesHydrochloric acid (HCl)1) Most is used to clean metals (pickling)2) Also called muriatic acidSulfuric acid (H2SO4)1) The most widely used chemical in the world2) Most of it is used to make fertilizer3) It is a good dehydrating agent4) It is used in car batteries
24Properties of Bases Bases feel slippery Bases are electrolytes Bases are corrosive, poisonous, and can cause severe burns (Lye = conc. NaOH)Bases turn litmus blue; Blue = BaseBases = pH greater than 7Big in Base6) Bases neutralize acids
25Common Bases – Ref. L Ammonia NH3 1) The most widely used base2) Used in household cleaning materials3) Used as fertilizer; adds nitrogen to soilCalcium hydroxide (caustic lime) Ca(OH)21) Used to make mortar and plaster2) Used to help neutralize acid soilSodium hydroxide (Lye) NaOH1) One of the strongest bases2) Used in oven cleaners and drain cleaners
27Always Use Ref. Tables Acids ending = “- ic” Bases = Metal + hydroxide (vinegar)
28Reactions of Acid with metals Use table J!Metals above H2 in table J react with acids by a single replacement reaction producing H2.2 HCl + Zn H2 + ZnCl2
29Neutralization Reaction Acids and bases react to neutralize each other, forming water and a salt:Acid + Base Water + SaltHA + XOH H2O + XADouble Replacement Reaction
30Ma x Va = Mb x V b Titration Is a process that uses a neutralization to determine the concentration of an acid or a base. Concentration in molarity is the amount of moles of solute per liter of solution. When the reaction of neutralization is 1:1 we use the following formula in a titrationMa x Va = Mb x V b
31Vocabulary Standard solution : the solution of known molarity Buret : instrument to measure exact volumes of liquidsErlenmeyer FlaskIndicator : a substance that changes color in the presence of an acid or base.End point: when the amount of H+ = OH-
55P 178 rb answers 14. chlorate 15 a) hydrosulfuric acid b) hydrobromic acidc) lithium hydroxided) magnesium hydroxide16. An electrolyte can also be a base or a salt. An indicator can be added to test if is an acid or a base.
56Page 187 answers 4 1 3 2 2 Bromocresol green Bet 5.4 and 6 A blue yellow74) B75) 1
57Handout Answers 2 4 3 pH=6 Methyl orange/ Bromthymol blue Bromocresol green