IONIC COMPOUNDS:ACIDS AND BASESChapter 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

WATERBefore understanding Acids and Bases, you must

understand water.1. It is a polar molecule. Like a magnet.

+ +- -

WATER1. It is a polar molecule. WHY???Oxygen pulls on the electrons more than Hydrogen does.

Oxygen = Higher ionization energy.

+ +- -

WATERBecause 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/dissolve.html

Acids• Acids: compounds that produce HYDRONIUM

IONS when dissolved in water.

•HCl + H20 H3O1+ +Cl1-

• Written also as:

HCl H1+ +Cl1-

AcidsAcidsAcidsAcids

When HCl is put in water, a Hydronium ion, H3O1+ (hydrogen ion, H1+) is formed.

Why might acids be referred to as “PROTON DONORS”?

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: Acids: IONIZATIONIONIZATIONAcids: Acids: IONIZATIONIONIZATION

Acids ARE “PROTON DONORS”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

Characteristics of Acids1. Taste Sour2. React Strongly with Metals and

Carbonates (in soil and rocks) 3. Burn skin4. Conduct electricity in water5. Turn blue litmus paper red

Characteristics of Acids1. Taste Sour2. React Strongly with Metals and

Carbonates (in soil and rocks) 3. Burn skin4. Conduct electricity in water5. Turn blue litmus paper red

AcidsAcidsAcidsAcids

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: Bases: DISSOCIATIONDISSOCIATIONBases: Bases: DISSOCIATIONDISSOCIATION

Bases are Ionic compounds that break apart (dissolve) in water to form a negatively charged hydroxide ion (OH 1-).

Why might bases be referred to as “PROTON ACCEPTORS”?

Bases are Ionic compounds that break apart (dissolve) in water to form a negatively charged hydroxide ion (OH 1-).

Why might bases be referred to as “PROTON ACCEPTORS”?

http://web.umr.edu/~gbert/ANIMATED/Asoly.HTML

BasesBasesBasesBases

Bases ARE “PROTON ACCEPTORS”Bases ARE “PROTON ACCEPTORS”http://www.mhhe.com/physsci/chemistry/animations/chang_7e_esp/acm2s2_1.swf

http://www.learning.gov.sk.ca/branches/elearning/tsl/resources/subject_area/science/chem_30_resources/lesson_8/acids_and_bases.shtml

BasesBasesBasesBasesCharacteristics of BasesCharacteristics of Bases1.1. Taste bitterTaste bitter2.2. Feel Slippery Feel Slippery 3.3. Burn your SkinBurn your Skin4.4. Conduct electricity in waterConduct electricity in water5.5. Turn red litmus paper blueTurn red litmus paper blue

Characteristics of BasesCharacteristics of Bases1.1. Taste bitterTaste bitter2.2. Feel Slippery Feel Slippery 3.3. Burn your SkinBurn your Skin4.4. Conduct electricity in waterConduct electricity in water5.5. Turn red litmus paper blueTurn 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 NaOH Drain cleaner, soap production

Strength of Acids and Bases – Journal 31. Fill in the “Identifying Acids and Bases” Worksheet.2. How can you tell how strong an acid or a base is?3. What do the numbers on the scale below mean?

4.4. What does “0” represent? What does “7” What does “0” represent? What does “7” represent? What does “14” represent?represent? What does “14” represent?

Strength of Acids and BasesWhich would you say is MORE acidic:

• battery acid • Or milk?

WHY is battery acid MORE ACIDIC?

Strength of Acids and Bases1. MORE hydronium (H(H33O O 1+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 (H(H33O O 1+1+)) ions in a solution.

2. This is the pH ScalepH Scale.

Strength of Acids and Bases

1.1. The pHThe pH of a solution is a measure of the hydronium ion (H(H33O O 1+1+)) concentration.

Strength of Acids and Bases

1. Neutral substances have a value of 72. 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 Bases1. Acids have a pH value of LESS THAN 7

2. Bases have a pH value of MORE THAN 7

3. What is the strongest acid on the chart?4. What is the strongest base?5. What is the weakest acid?6. 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

sodiumPotassium 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?