ACIDS AND BASES Chapter 8 - Honors

Properties of Acids and Bases – Journal 1 Read and highlight Sections on the worksheet from the back table. Make vocabulary flashcards for Sections 8.3 & 8.4 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 + H 2 O  H 3 O 1+ (aq) +Cl 1- (aq) NaOH (s)  Na 1+ (aq) + OH 1- (aq)

WATER Before understanding Acids and Bases, you must understand water. 1.It is a polar molecule. Like a magnet

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

Acids Acids: compounds that I II IONIZE and produce HYDRONIUM IONS when dissolved in water. HCl + H 2 0  H 3 O 1+ +Cl 1- Written also as: HCl  H 1+ +Cl 1-

AcidsAcids When HCl is put in water, a Hydronium ion, H 3 O 1+ (hydrogen ion, H 1+ ) 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: ionization Acids ARE “PROTON DONORS” Acids ARE “PROTON DONORS”

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 (electrolyte) 5.Turn blue litmus paper red 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 (electrolyte) 5.Turn blue litmus paper red AcidsAcids

Common Acids Acetic acidCH 3 COOHVinegar Carbonic acidH 2 CO 3 Carbonated beverages Hydrochloric acidHCIDigestive juices in stomach Nitric acidHNO 3 Fertilizer production Phosphoric acidH 3 PO 4 Fertilizer production Sulfuric acidH 2 SO 4 Car batteries

Bases Bases: ionic compounds that D DD DISSOCIATE and produce HYDROXIDE IONS when dissolved in water. NaOH (s)  Na 1+ (aq) + OH 1- (aq)

BasesBases Bases are Ionic compounds that break apart (dissociate) 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 (dissociate) in water to form a negatively charged hydroxide ion (OH 1- ). Why might bases be referred to as “PROTON ACCEPTORS”?

BasesBases Bases ARE “PROTON ACCEPTORS” Bases ARE “PROTON ACCEPTORS”

BasesBases Characteristics of Bases 1.Taste bitter 2.Feel Slippery 3.Burn your Skin 4.Conduct electricity in water (electrolyte) 5.Turn red litmus paper blue Characteristics of Bases 1.Taste bitter 2.Feel Slippery 3.Burn your Skin 4.Conduct electricity in water (electrolyte) 5.Turn red litmus paper blue

Common Bases Aluminum hydroxideAl(OH) 3 Deodorant, antacid Calcium hydroxideCa(OH) 2 Concrete, plaster Magnesium hydroxideMg(OH) 2 Antacid, laxative Sodium hydroxideNaOH Drain cleaner, soap production

Strength of Acids and Bases Which would you say is MORE acidic: battery acid Or milk? WHY is battery acid MORE ACIDIC?

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 p pp pH Scale.

Strength of Acids and Bases 1.T he 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.A cids have a pH value of LESS THAN 7 2.B ases have a pH value of MORE THAN 7 3.W hich are the strongest acids and bases? 4.W hich are the weakest acids and bases? 5.W hat is NEUTRAL?

Acids and Bases - JOURNAL 1.F ill in the Identifying Acids and Bases sheet.

Strength of Acids and Bases What is the difference between the strong and the weak, regardless of concentration? Strong substances IONIZE/DISSOCIATE COMPLETELY.

How do you get strong and weak acids and bases? STRONG ACIDS/BASES COMPLETELY IONIZE/DISSOCIATE HCl + H2OH3O + + Cl – –R–R–R–Reaction only goes in one direction. WEAK ACIDS/BASES DO NOT dissociate/ionize completely NH3 + H2O NH4+ + OH – –R–R–R–Reaction goes in both directions. Not all of the compound ionizes. –h–h–h–h tttt tttt pppp :::: //// //// wwww wwww wwww.... mmmm hhhh hhhh eeee.... cccc oooo mmmm //// pppp hhhh yyyy ssss ssss cccc iiii //// cccc hhhh eeee mmmm iiii ssss tttt rrrr yyyy //// cccc hhhh aaaa nnnn gggg 7777 //// eeee ssss pppp //// ffff oooo llll dddd eeee rrrr ____ ssss tttt rrrr uuuu cccc tttt uuuu rrrr eeee //// aaaa cccc //// mmmm 2222 //// ssss 1111 //// aaaa cccc mmmm 2222 ssss 1111 ____ hhhh tttt mmmm

pHH 3 O 1+ concentration x x x x x x x x x x x x x x x If you multiplied this number by 100, what would be your chances of finding a hydronium ion in solution? 100% 10% 1% So, your chances get slimmer as the exponent gets LARGER. The fewer the H 3 O 1+, the weaker the acid. If pH is the measure of hydronium ions, why are acids the lowest numbers?

Strength of Acids and Bases – Journal Fill in the Acids and Bases Practice Sheet.

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  H 2 O + NaCl

Common Salts Sodium chlorideNaClFood flavoring, preservative Sodium carbonateNa 2 CO 3 Used to make glass Potassium chlorideKClUsed as a salt substitute to reduce dietary intake of sodium Potassium iodideKlAdded to table salt to prevent iodine deficiency Magnesium chlorideMgCl 2 De-icer for roads Calcium carbonateCaCO 3 Chalk, marble floors, and tables Ammonium nitrateNH 4 NO 3 Fertilizer, cold packs

Acids and Bases and Neutralization One of the most important aspects of a living system is the amount of acidity or alkalinity

NEUTRALIZATION NEUTRALIZATION: Why do we need to know? NEUTRALIZATION NEUTRALIZATION: Why do we need to know? Control of pH is very important Control is accomplished with buffers

Buffers neutralize small amounts of either an acid or base. NEUTRALIZATION NEUTRALIZATION: Why do we need to know? NEUTRALIZATION NEUTRALIZATION: Why do we need to know?

Alkalinity – the ability of a stream to neutralize acids. NEUTRALIZATION NEUTRALIZATION: Why do we need to know? NEUTRALIZATION NEUTRALIZATION: Why do we need to know?

Properties of Acids and Bases – Journal 5 Come in, take out your homework, and get your LAB sample.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?