Transcript IONIC COMPOUNDS: ACIDS AND BASES

IONIC COMPOUNDS:
ACIDS AND BASES
Chapter 8 - CP
Properties of Acids and Bases – Journal 1
• SILENTLY, Read and Highlight the 8.3 and 8.4
part of the Worksheet from the back table,
THEN make flashcards for section 8.3 and 8.4
vocabulary.
• I will be coming around with samples for you
to taste. Classify each of the liquids as an
Acid, Base or Neutral based on what you
learn about the characteristics of acids and
bases in your reading.
Acids and Bases
• Acids and Bases are Compounds that have
very distinct properties.
HCl + H2O  H3O
1+
+Cl
1-
NaOH + H2O  Na 1+ + OH 1- + H2O
WATER
Before understanding Acids and Bases, you must
understand water.
1. It is a polar molecule. Like a magnet.
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+
-
+
WATER
1. It is a polar molecule. WHY???
Oxygen pulls on the electrons more than Hydrogen does.
Oxygen = Higher ionization energy.
-
+
-
+
WATER
Because water is POLAR (negative side and
positive side), what types of compounds will it
DISSOLVE easily?
CHARGED
http://www.northland.cc.mn.us/biology/Biology1111/animations/di
ssolve.html
-
+
-
+
Acids
• Acids: compounds that produce HYDRONIUM
IONS when dissolved in water.
•HCl + H20 
1+
H3O
1+Cl
• Written also as:
HCl 
1+
H
1+Cl
Acids
When HCl is put in water, a Hydronium ion,
H3O1+ (hydrogen ion, H1+) is formed.
Why might acids be referred to as “PROTON
DONORS”?
Acids: IONIZATION
Acids ARE “PROTON DONORS”
http://www.learning.gov.sk.ca/branches/elearning/tsl/resources/subject_area/science/chem_30_resources/lesson_8/acids_and_bases.shtml
Acids
Characteristics of Acids
1. Taste Sour
2. React Strongly with Metals and
Carbonates (in soil and rocks)
3. Burn skin
4. Conduct electricity in water
5. Turn blue litmus paper red
Common Acids
Acetic acid
CH3COOH Vinegar
Carbonic acid
H2CO3
Carbonated beverages
Hydrochloric acid
HCI
Digestive juices in stomach
Nitric acid
HNO3
Fertilizer production
Phosphoric acid
H3PO4
Fertilizer production
Sulfuric acid
H2SO4
Car batteries
Bases
• Bases: ionic compounds that produce
HYDROXIDE IONS when dissolved in water.
NaOH  Na 1+ + OH 1-
Bases: DISSOCIATION
Bases are Ionic
compounds that break
apart (dissolve) in
water to form a
negatively charged
hydroxide ion (OH 1-).
http://web.umr.edu/~gbert/ANIMATED/Asoly.HTML
Why might bases be
referred to as
“PROTON
ACCEPTORS”?
Bases
http://www.learning.gov.sk.ca/branches/elearning/tsl/resources/subject_area/science/chem_30_resources/lesson_8/acids_and_bases.shtml
Bases ARE “PROTON ACCEPTORS”
http://www.mhhe.com/physsci/chemistry/animations/chang_7e_esp/acm2s2_1.swf
Bases
Characteristics of Bases
1. Taste bitter
2. Feel Slippery
3. Burn your Skin
4. Conduct electricity in water
5. Turn red litmus paper blue
Common Bases
Aluminum hydroxide
Al(OH)3
Deodorant, antacid
Calcium hydroxide
Ca(OH)2
Concrete, plaster
Magnesium hydroxide Mg(OH)2
Antacid, laxative
Sodium hydroxide
Drain cleaner, soap production
NaOH
Strength of Acids and Bases – Journal 3
1.
2.
3.
Fill in the “Identifying Acids and Bases” Worksheet.
How can you tell how strong an acid or a base is?
What do the numbers on the scale below mean?
4. What does “0” represent? What does “7”
represent? What does “14” represent?
Strength of Acids and Bases
•
•
Which would you say is MORE acidic:
battery acid
Or milk?
WHY is battery acid MORE ACIDIC?
Strength of Acids and Bases
1. MORE hydronium (H3O 1+) ions.
2. How many hydronium ions are in the strong
acid? In the weak acid?
Strength of Acids and Bases
1. Chemists use a number scale from 0 to 14 to
describe the concentration (amount of)
hydronium (H3O 1+) ions in a solution.
2. This is the pH Scale.
Strength of Acids and Bases
1. The pH of a solution is a measure of the
hydronium ion (H3O 1+) concentration.
Strength of Acids and Bases
1. Neutral substances have a value of 7
2. Their number of hydronium ions equal their
number of hydroxide ions.
Strength of Acids and Bases
1. Distilled water is neutral.
2. It’s hydronium ions equal it’s hydroxide ions
This is because water ionizes slightly.
Strength of Acids and Bases
1. Acids have a pH value of LESS THAN 7
2. Bases have a pH value of MORE THAN 7
3.
4.
5.
6.
What is the strongest acid on the chart?
What is the strongest base?
What is the weakest acid?
The weakest base?
Properties of Acids and Bases – Journal 2
• Come in and take out your homework
(pH Lab).
• Fill in the Acids and Bases practice
from the back table.
• Read and answer the questions on the
Neutralization Worksheet from the
back table.
Reactions between Acids and Bases
• When bases REACT with acids, the process is
called NEUTRALIZATION.
Reactions between Acids and Bases
• When bases REACT with acids, the process is
called NEUTRALIZATION.
• They react to form a salt and water (& HEAT)
• Hydrochloric Acid + Sodium Hydroxide  Water + Table Salt
HCl + NaOH  H2O + NaCl
Take out the neutralization worksheet.
Common Salts
Sodium chloride
NaCl
Food flavoring, preservative
Sodium carbonate
Na2CO3
Used to make glass
Potassium chloride
KCl
Used as a salt substitute to
reduce dietary intake of sodium
Potassium iodide
Kl
Added to table salt to
prevent iodine deficiency
Magnesium chloride MgCl2
De-icer for roads
Calcium carbonate
CaCO3
Chalk, marble floors, and tables
Ammonium nitrate
NH4NO3
Fertilizer, cold packs
Properties of Acids and Bases – Journal 5
• Come in, take out your homework, and get
your LAB sample.
• Write an equation that shows
NEUTRALIZATION. Include the names of the
REACTANTS and PRODUCTS.
• What is the range of the pH scale? The range
for acids? Bases? Neutral?
• What is the strongest Acid value? Base value?
What would be a weak acid? Weak base?