Chapter 14 Acids & Bases 14.1 Properties of Acids and Bases.
Chemistry Day 80 · • Quiz on Kinetics/Acids + Bases next class • Study! Unit test: Thermo,...
Transcript of Chemistry Day 80 · • Quiz on Kinetics/Acids + Bases next class • Study! Unit test: Thermo,...
Chemistry Day 80 P. 4: Monday, May 6th, 2019 P. 5: Wednesday, May 8th, 2019
Do-Now: “BrainPOP: Acids & Bases” 1. Write down today’s FLT 2. The pH scale ranges from ____ to ____. 3. Which is more acidic: pH 3 or pH 6? 4. Which is more basic: pH 3 or pH 6? 5. If you have a pH of 3, what is your pOH? 6. What is the pH of a solution if the [H+] is 1.5 x 10-6 M? Show all steps. 7. Take out your planner and ToC
Announcements• APTestingstartsthisweek!Berespectfulofnoisearoundtestingareas
Planner:• QuizonKinetics/Acids+Basesnextclass• Study!Unittest:Thermo,Spontaneity,Kinetics,Acids/Bases
Table of Contents #3: 17. BrainPOP: Acids and Bases 18. Acids/Bases CN Part C 19. Acids/Bases WS C
BrainPOP:Acids&Bases• WatchtheBrainPOPvideo• Afterthevideo,answerthequestionsinyourgroup–everymembermustcopydownthesameanswer
• Thegroupwiththemostcorrectanswersà+5dojopointseach
https://www.brainpop.com/science/matterandchemistry/acidsandbases/
FLT• Iwillbeabletodefinestrongacidsandweakacids&definetheproductsofanacid-basereactionbycompletingCh.16CNpartC
Standard HS-PS3-1:Createacomputationalmodeltocalculatethechangeintheenergyofonecomponentinasystemwhenthechangeinenergyoftheothercomponent(s)andenergyflowsinandoutofthesystemareknown
Acid/BaseStrength&Neutralization
Recall
Recall • The pH scale ranges from 0-14 • What’s more acidic? • What’s more basic?
Recall • Brønsted-Lowryacids:
– DonateH+
• Brønsted-Lowrybases:– Accept H+
Recall • Acids and bases are
electrolytes • This means that they
dissociate into ions in water
Recall • What if they only dissociate a little bit?
Electrolytes and Nonelectrolytes • Weakelectrolytes=onlypartiallyionizeWeakelectrolyteshaveonlyafractionofthesolutethatexistsasions(about1%)– Weakacidsandbases;ammonia,aceticacid
Acid/BaseStrength
Acid/Base Strength • Acids are classified as strong or weak
depending on the degree to which they ionize in water
Acid/Base Strength • Strong acids = completely ionize in water • Ex/ HCl, HNO3, H2SO4
HCl(g) + H2O(l) à H3O+(aq) + Cl-(aq)
100% ionized
Acid/Base Strength • Weak Acids = ionize only slightly in water. • Ex/ Ethanoic (acetic) acid CH3COOH and
HF CH3COOH(aq) + H2O(l) ßà H3O+
(aq) + CH3COO-(aq)
Acid/Base Strength • Bases are also classified as strong or weak
depending on the degree to which they ionize in water
Acid/Base Strength • Strong bases = completely dissociate
into metal ions and OH- ions in water • Ex/ Ca(OH)2, NaOH, KOH
Acid/Base Strength • Weak Bases = Produce a small amount of
OH- in water • Ex/ Ammonia (NH3)
NH3(aq) + H2O(l) ßà NH4+
(aq) + OH-(aq)
99% NH3 still present, ~1% ionized
ConjugateAcids&Bases
TheBrønsted-LowryDefinition• Wecanlabelouracid-basereactionsusingproton-transfer
• Ex1:
HCl(aq)+H2O(l)àH3O+(aq)+Cl-(aq)
• Ex2:
NH3(aq)+H2O(l)ßàNH4+(aq)+OH-
(aq)
Donated(Lost)H+
Donated(Lost)H+
Accepted(gained)H+
Accepted(gained)H+
Acid
Acid
Base
Base
Conjugate Acids & Bases • In this equation, what is the acid? What is
the base?
Conjugate Acids & Bases • Note: This is a reversible reaction. The back
reaction is also an acid-base reaction. • Which is the acid and which is the base?
Conjugate Acids & Bases • Conjugate Acid = formed when a base
gains H+
Conjugate Acids & Bases • Conjugate Base = formed when an acid
loses H+
TheBrønsted-LowryDefinition• Wecanlabelouracid-basereactionsusingproton-transfer
• Ex1:
HCl(aq)+H2O(l)àH3O+(aq)+Cl-(aq)
• Ex2:
NH3(aq)+H2O(l)ßàNH4+(aq)+OH-
(aq)
Donated(Lost)H+
Donated(Lost)H+
Accepted(gained)H+
Accepted(gained)H+
Acid
Acid
Base
Base
Conj.acid
Conj.base
Conj.acid
Conj.base
Try This: • In the equation below, label the acid, base,
conjugate acid, and conjugate base.
HNO3(aq) + CH3OH ßà CH3OH2+
(aq) + NO3-(aq)
Donated(Lost)H+
Acid Conj.base
Base Conj.acid
Accepted(gained)H+
Conjugate Acids & Bases • Conjugate Acid-Base Pair Strengths:
– Strong acids/bases form weaker conjugates – Weak acids/bases form stronger conjugates
LastTidbits
Last Tidbits • Amphoteric substances = act as both an
acid or a base
NH3 + H2O ↔ NH41+ + OH1-
base acid c.a. c.b. HCl + H2O ↔ H3O1+ + Cl1-
acid base c.a. c.b.
Last Tidbits • Neutralization Reaction - a reaction in
which an acid and a base react in an aqueous solution to produce a salt and water:
HCl(aq) + NaOH(aq) à NaCl(aq) + H2O(l)
H2SO4(aq) + KOH(aq)à ?
Last Tidbits • Acid + Base à Water + Salt • Properties related to every day:
– antacids depend on neutralization – farmers adjust the soil pH – formation of cave stalactites – human body kidney stones from
insoluble salts
Pair-Share-Respond1. Distinguishbetweenstrongandweakacids
2. Distinguishbetweenstrongandweakbases
3. Whatareconjugateacids?4. Whatareconjugatebases?5. Howcanyoudetermineifyourconjugateacid/baseisstrongorweak?
Chemistry Day 81 Tuesday, May 7th – Wednesday, May 8th, 2019
Do-Now: “Kinetics/Acids/Bases Quiz Day Do-Now” 1. Write down today’s FLT 2. What is the formula for pH? 3. How do you determine how many decimal
places your pH should have? 4. Distinguish between the acids “hydrosulfuric
acid” and “sulfuric acid” 5. Copy the equation: H2CO3 + H2O à H3O+ +
HCO3-
6. Identify the base and conjugate base in the reaction in #5. Use work/labeling to justify your choices.
Chemistry Day 82 Thursday, May 9th – Friday, May 10th, 2019
Do-Now: “Unit Test Day Do-Now” 1. Write down the FLT 2. How do you determine how many decimal
places your pH should have? 3. Distinguish between the acids “sulfuric acid”
and “sulfurous acid” 4. How can you use an energy diagram to
determine if your reaction is exo- or endothermic?
5. Distinguish between temperature at STP and temperature at standard conditions
6. Take out your planner, reference sheet, and ToC