What 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.
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AcidsBases Taste sour Corrosive React with some metals to
produce H 2 Change Litmus to red acid= red React with bases to form
water and salt. Bases taste bitter Feel slippery Corrosive Change
Litmus to blue base = Blue Become less basic when mixed with
acids.
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Always Use Ref. Tables (vinegar)
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Table L Common Bases Formula Name NaOH(aq) sodium hydroxide
KOH(aq) potassium hydroxide Ca(OH) 2 (aq) calcium hydroxide NH 3
(aq) aqueous ammonia
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Svante Arrhenius 1859 - 1927 Swedish chemist, proposed theories
of electrolytic disassociation (acids/bases) and greenhouse
effect.
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Arrhenius 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
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Nature of the Hydrogen Ion or Proton Proton is so small that
does not exist isolated in water. H + + H 2 O H 3 O + Hydronium
Ion
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Nature 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!!!!
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HOW TO NAME ACIDS NO OXYGEN IN FORMULA HYDRO ----- ACID HCl
Hydrochloric acid HBr Hydrobromic acid HF Hydrofluoric acid H 2 S
Hydrosulfuric acid OXOA CIDS CONTAIN OXYGEN IN FORMULA ENDING OUS
if ion ends ITE IC if ion ends in ATE Use table E
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Solutions of Ionic Compounds conduct electricity = Electrolytes
Electrolytes ions (charged particles) in solution. HCl (aq) H + +
Cl - Hydrochloric Acid H+H+ Cl -
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Solutions ; Release OH - (aq) Metal (+) and Non-Metal (-)
Electrolytes conduct electricity when dissolved in H 2 O
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Solutions = Salts (ionic), acids, & bases Salts = ionic (+)
(-) Strong Acid & Base Weak Acid or Weak Base Covalent = no
ions brightdim dark
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Conductivity apparatus Electrolytes conduct electricity when
dissolved in water
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STRONG ACIDS COMPLETELY DISSOCIATED If the solution is 2 M in
HCl it produces 2 mol of H + and 2 mol of Cl-
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WEAK ACIDS Partially dissociated. Molecules stay together and
only some of them dissociate.
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
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Ternary Acids - molecular (covalent) - composed of hydrogen +
oxygen containing polyatomic ion (Ref. E) Ex. HNO 3 Nitric Acid (NO
3 1- Nitrate ion) HNO 2 Nitrous Acid (NO 2 1- Nitrite ion) H 2 SO 4
Sulfuric Acid(SO 4 2- Sulfate ion) Ternary Acids = Anion suffix
(-ate or -ite) is dropped and replaced with -ic or -ous
respectively.
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TABLE M common acids HCl(aq) hydrochloric acid HNO 3 (aq)
nitric acid H 2 SO 4 (aq) sulfuric acid H 3 PO 4 (aq) phosphoric
acid H 2 CO 3 (aq) carbonic acid CH 3 COOH(aq) ethanoic acid HC 2 H
3 O 2 (aq) (acetic acid)
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Common Acids Ref. K Nitric acid (HNO 3 ) 1) Most is used to
make fertilizer 2) Well known for making explosives Hydrochloric
acid (HCl) 1) Most is used to clean metals (pickling) 2) Also
called muriatic acid Sulfuric acid (H 2 SO 4 ) 1) The most widely
used chemical in the world 2) Most of it is used to make fertilizer
3) It is a good dehydrating agent 4) It is used in car
batteries
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Properties of Bases 1)Bases feel slippery 2)Bases are
electrolytes 3)Bases are corrosive, poisonous, and can cause severe
burns (Lye = conc. NaOH) 4)Bases turn litmus blue; Blue = Base
5)Bases = pH greater than 7 Big in Base 6) Bases neutralize
acids
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Common Bases Ref. L Ammonia NH 3 1) The most widely used base
2) Used in household cleaning materials 3) Used as fertilizer; adds
nitrogen to soil Calcium hydroxide (caustic lime) Ca(OH) 2 1) Used
to make mortar and plaster 2) Used to help neutralize acid soil
Sodium hydroxide (Lye) NaOH 1) One of the strongest bases 2) Used
in oven cleaners and drain cleaners
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Always Use Ref. Tables Acids ending = - ic Bases = Metal +
hydroxide (vinegar)
What is pH ? ( p 539) pH is the negative logarithm of the
hydrogen ion concentration = pH = - log [H + ] Remember that
sometimes H + is written H 3 O +, so pH = - log [H 3 O + ] means
the same thing.
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May 20 DO NOW! Find the pH for A) 0.0001 M HCl B) 0.01 M HBr C)
0.001 M NaOH
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pH Scale = log (base 10) scale An increase of 1 in pH
corresponds to a decrease of a factor of 10 in H + concentration.
pH is.. Big in Base & Blue
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Typical pH Values of Common Materials Oven Cleaner / Drain
Cleaner Hair Remover Baking Soda Soap Ammonia (NH 3 ) Lemon Juice
Coffee / Tea Blood Battery Acid Saliva Pure Water Seawater Stomach
Acid Milk Vinegar, Soft Drinks Tomatoes Basic Acidic Neutral
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More about pH Kw = dissociation constant for water = 10 -14 1 x
10 -14 = [H + ] x [OH - ] = [ 10 -7 ] x [ 10 -7 ] A neutral
solution has a pH of 7. [H+] = [OH-] = 1 x 10 -7 M
Finding pH for a solution of a strong acid or strong base For
strong acid the concentration of the acid is the same as H + For
strong bases the concentration of the base is the same as OH
-.
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Acid-Base Indicators A substance that have different colors at
different pH. They are used to find out the pH of solutions.
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Always Use Ref. Tables (vinegar)
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May 22 Acid Base Reactions A) Acids with metals - More detail
next unit B) Neutralization reactions and titration Section 3 in
textbook STUDY!!!! (P 548)
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Reactions of Acid with metals Use table J! Metals above H 2 in
table J react with acids by a single replacement reaction producing
H 2. 2 HCl + Zn H 2 + ZnCl 2
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Neutralization Reaction Acids and bases react to neutralize
each other, forming water and a salt: Acid + Base Water + Salt HA +
XOH H 2 O + XA Double Replacement Reaction
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May 23 Titration Practice problems Homework take home test MAKE
SURE YOU TAKE SCANTRON SHEET AND TEST QUESTIONS. DUE TUESDAY MAY 27
at the beginning of the period!
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
titration Ma x Va = Mb x V b
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Vocabulary Standard solution : the solution of known molarity
Buret : instrument to measure exact volumes of liquids Erlenmeyer
Flask Indicator : a substance that changes color in the presence of
an acid or base. Equivalence point: when the amount of H + = OH -
(by stoichiometry) End Point : when the indicator changes
color
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Buret Instrument to measure exact volumes of liquids
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Acid H + Base OH - Acid Base Titration Erlenmeyer flask Two
Burets with valves at bottom. Record vol. in mL (twice) Color
indicator = phenolphthalein
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At the end point Ma x Va = Mb x V b
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Examples # 47 How many ml of 2.5 M HCL are required to exactly
neutralize 1.5 L of 5.0 M NaOH?
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# 48 How many ml of.020 M H2SO4 are required to completely
neutralize 40. mL of 0.10 M Ca(OH)2
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# 51 A 10. mL sample of HCl neutralizes 15 mL of a 0.40 M
solution of NaOH. What is the molarity of the acid?
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P 177 REVIEW BOOK 1)2 2)1 3)1 4)2 5)4 6)4 7)1 8)3 9)2 10)2 11)4
12)1 13)1
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P 185 answers (titration problems) 40)4 41)2 42)2 43)1 44)4
45)2 46)25 ml 47)3000ml 48)20mL 49)50mL 50)6M
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P 178 rb answers 14. chlorate 15 a) hydrosulfuric acid b)
hydrobromic acid c) lithium hydroxide d) magnesium hydroxide 16. An
electrolyte can also be a base or a salt. An indicator can be added
to test if is an acid or a base.
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Page 187 answers (pH and indicators) 61)4 62)1 63)3 64)3 65)3
66)2 67)1 68)1 69)4 70)2 71)Bromocresol green 72)Bet 5.4 and 6 73)A
blue yellow 74) B 75) 1
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Handout Answers 1)2 2)2 3)4 4)2 5)3 6)3 7)4 pH=6 Methyl orange/
Bromthymol blue Bromocresol green