Acid/Base Review
List the properties of Acids
• Sour, H3O+ ions, strong acids conduct, react with metals to form H2 gas, neutralize bases to form salt + water. Acids Ionize with water to form H3O+, litmus red
List the properties of bases
• Bitter, slippery, OH- ions, strong bases conduct, , neutralize acids to form salt + water. Strong bases dissociate (water on arrow), litmus blue
List the 6 strong acids
• HBr• HI• HCl
• HNO3
• H2SO4
• HClO4
• Remember these acids ionize completely in water creating a strong electrolyte!
Explain the difference between an oxyacid and a binary acid and give
an example of each
• Oxyacid has oxygen in the compoundH2SO4
• Binary acid means that there are two compounds present HCl
List common acids that we have talked about
• Phosphoric Acid-found in soda/used to make fertilizer
• HCl-found in the stomach
• Acetic Acid-vinegar
Give two examples of weak acids and one example of a weak base
• H2S-Hydrosulfuric Acid
• HCH3COO-acetic acid
• NH3 – ammonia (weak base)
List the strong bases
• Anything in column 1 & 2 bonded with an OH-
Explain the Arrhenius Acid Definition
• Acids produce H+ in solution• Acid – produces H+ in water
• HCl + H2O H3O+ + Cl-
• H2SO4 + H2O 2H3O+ + SO42-
• Remember H+ can also mean H3O+ (Hydronium Ion)
• Base – produces OH- in water NaOH Na+ + OH-
NH3 + H2O NH4
+ + OH-
Explain the Arrhenius Base Definition
Explain the Bronsted-Lowrey Definition of Acids/Bases
• Acids are H+ donors, • bases are proton (H+ ) acceptors.
• HCl + H2O Cl + H3O+
acid base
• Bronsted-Lowry is a way to study proton transfer!!
Explain conjugate Acid/Base
• Conjugate Acid – formed when BL base gains a proton
• Conjugate Base – formed when BL acid looses a proton
• HCl + NH3 NH4+ + Cl-
• a b ca cb
• H2SO4 + 2H2O 2 H3O+ + SO42-
a b ca cb
If I have a strong acid what is the strength of the conjugate base?
• The stronger the acid, the weaker its conjugate base; the stronger the base, the weaker its conjugate acid
Study your conjugate acid/base worksheet as there are a few questions on recognizing a/cb
and b/ca pairs
What is an amphoteric substance and give an example
• Water:
• can react as either an acid or base• HCl + Water H3O + + Cl -
proton acceptor(water)
• Water + NH3 NH4 + + OH - Water(proton donor)
Complete the following Reactions
• 3KOH + H3PO4 →
K3PO4 + 3 H2O
• Mg(OH)2 + 2 HCl →
2H2O + MgCl2
• Strong because they will completely ionize or dissociate creating many ions…….
• Weak acids/bases do not ionize completely thus there are fewer electrons, thus they are not very strong electrolytes
Are strong acids/bases strong or weak electrolytes?
How many moles of Nitric acid are in 500 ml of a 10 M HNO3 solution?
• 5 moles
What does pH measure?
pH – related to the concentration of H3O + ions in solutions. The more H3O+ ions, the lower the pH.
Given the H3O+ concentration find the pH / pOH…A/N/B
• [H3O+]=7.3x10-13
– pH=12.13– pOH=1.86– Basic
• [H3O+]=5x10-2
– pH=1.3– pOH=12.2– Acidic
Given the pH find the Hydronium or hydroxide ion concentration
• pH= 3.1
• [H3O+]= 7.9x10-4
• pH= 10.5
• [H3O+]=3.2x10-11
Draw a strong acid/strong base titration curve
Draw a weak base strong acid titration curve
Summary of titration curves
During a titration curve why do we have to titrate so slowly when we
get close to the equivalence point/end point?
• When the hydronium ions and hydroxide ions are nearly equal (the equivalence point) the curve of graph is very steep and thus happens very quickly.
Explain the End Point
• When the indicator changes color which should be close to the equivalence point if chosen correctly.– Ex. Strong acid/strong base should be litmus – Ex. Strong base/weak acid should be
phenolphthalein
What is the pH of a .036M LiOH solution
• First find the pOH by finding the normality – Remember normality = molarity x equivalence – Then you take the –log (normality concentration)
-log (.036)=1.44 but that equals the pOHThen you take 14-1.44=12.56 which gives you
the pHpH=12.56
To neutralize 20 ml of aqueous sulfuric acid, you use 32.5 ml of a 0.2 M NaOH
solution. Calculate the Molarity
• Molarity of H2SO4 =0.16
What volume of 0.5 M sulfuric acid is needed to react completely with 10 ml of
2.0 M LiOH
H2SO4 + 2LiOH → Li2SO4 + 2H2O
.02L
A 20 ml sample of 0.55 M KOH solution required 30 ml of aqueous acetic acid solution in a titration
experiment. Calculate M & N &pH of the acid.
• Molarity = HCH3COO=0.367
• Normality = M x eq = 0.367 x 1 = 0.367
• pH= -log [N]= -log(0.367) = .435
If you start with a pH of 1 and add water what should you expect to have happen to
the pH?
• You should expect it to neutralize
• pH of 1 = .1M
• When you add water you dilute it so the next step would be .01M. The pH would be 2.
• .001M = pH 3 etc.
• What would a graph look like?
You have a 4 M solution of NaOH. You need to make up 2000 ml of a 1.5 M solution. How many mls of the 4 M solution do you need? How much
water would you need?
• V1 x M1 = V2 x M2
• V1 x 4M = 2000 x 1.5
• V1=750ml
What is the salt produced when KOH is used to neutralize sulfuric
acid?
• K2SO4