chapter 16: equilibrium in acid-base systems
DESCRIPTION
Chapter 16: Equilibrium in Acid-Base Systems. 16.2a: Bronsted-Lowry Acid-Base Concept. Definition of Acid and Base. Bronsted-Lowry independently created by two scientists around the same time (1923) looked at how acid/base acted in reactions instead of their properties in aqueous solutions - PowerPoint PPT PresentationTRANSCRIPT
Chapter 16: Chapter 16: Equilibrium in Equilibrium in
Acid-Base SystemsAcid-Base Systems
16.2a: Bronsted-Lowry Acid-Base 16.2a: Bronsted-Lowry Acid-Base ConceptConcept
Definition of Acid and BaseDefinition of Acid and Base
Bronsted-LowryBronsted-Lowry independently created by two scientists independently created by two scientists
around the same time (1923)around the same time (1923) looked at how acid/base acted in reactions looked at how acid/base acted in reactions
instead of their properties in aqueous instead of their properties in aqueous solutionssolutions
theoretical definitions based upon proton theoretical definitions based upon proton transfer during a reactiontransfer during a reaction
Proton transfer conceptProton transfer concept
Acid: molecule or ion that is a proton (HAcid: molecule or ion that is a proton (H++) ) donordonor
HCl + HHCl + H22O O H H33OO++ + Cl + Cl--
Base: molecule or ion that is a proton (HBase: molecule or ion that is a proton (H++) ) acceptoracceptor
NHNH33 + H + H22O O NH NH44++ + OH + OH--
Bronsted-Lowry conceptBronsted-Lowry concept
B-L acid a proton donor; B-L base a B-L acid a proton donor; B-L base a proton acceptorproton acceptor
B-L neutralization is a competition B-L neutralization is a competition for protons from the SA to the SBfor protons from the SA to the SB
B-L rxtn. eqtn. is an eqtn. that shows B-L rxtn. eqtn. is an eqtn. that shows this transfer of protons from one this transfer of protons from one entity to anotherentity to another
Acids or Bases?Acids or Bases?
CC55HH55NN base (weak)base (weak)
Mg(OH)Mg(OH)22
base (strong)base (strong) HFHF
acid (weak)acid (weak)
NHNH33
base (weak)base (weak)
HH22COCO33
acid (weak)acid (weak)
HH22SOSO44
acid (strong)acid (strong) KOHKOH
base (strong)base (strong)
CHCH33NHNH22
base (weak)base (weak)
HCHC22HH33OO22
acid (weak)acid (weak) HIHI
acid (strong)acid (strong)
Acid – Base ReactionsAcid – Base Reactions Identify the acids and bases of the Identify the acids and bases of the
following reactionsfollowing reactions
CC66HH55NHNH22 + H + H22O O C C66HH55NHNH33++ + OH + OH--
BB AA HNOHNO33 + H + H22O O H H33OO++ + NO + NO33
--
AA BB HCHHCH33COO + HCOO + H22O O H H33OO++ + CH + CH33COOCOO--
AA B B
Acid-Base ReactionsAcid-Base Reactions
Amphoteric SubstancesAmphoteric Substances proper term used in B-L reactionsproper term used in B-L reactions a a substancesubstance that can react as either that can react as either
acid or base depending on what they acid or base depending on what they are mixed withare mixed with
example: water, HSOexample: water, HSO44--
AmphiproticAmphiprotic incorrect term to use with B-L rxtns.incorrect term to use with B-L rxtns. refers to an refers to an entityentity (ion or molecule) (ion or molecule)
Amphoteric WaterAmphoteric Water
Water as an acid (proton donor)
Water as a base (proton acceptor)
Conjugate Acid-Base Conjugate Acid-Base PairsPairs
Conjugate acids and bases are always Conjugate acids and bases are always created by a B-L reaction (as products)created by a B-L reaction (as products)
Conjugate baseConjugate base an acid that has lost a an acid that has lost a
HH++
missing a hydrogenmissing a hydrogen ex: Hex: H22POPO44
--, OH, OH--, Cl, Cl--
Conjugate acidConjugate acid a base that has gained a a base that has gained a
HH++
has an extra hydrogenhas an extra hydrogen NHNH44
++, C, C66HH55NHNH33++, H, H33OO++
A pair of substances with formulas that differ only by a proton is called a conjugate acid-base pair
Identify the parts of these Identify the parts of these reactionsreactions
CC66HH55NHNH22 + H + H22O O C C66HH55NHNH33++ + OH + OH--
basebase acid acid CA CB CA CB HNOHNO33 + H + H22O O H H33OO++ + NO + NO33
--
acidacid basebase CA CA CBCB HCHHCH33COO + HCOO + H22O O H H33OO++ + CH + CH33COOCOO--
acidacid basebase CA CA CBCB NHNH33 + H + H22O O NH NH44
++ + OH + OH--
base acidbase acid CA CA CB CB
HomeworkHomework
Textbook p724 #1-6Textbook p724 #1-6 Textbook p726 #7Textbook p726 #7 LSM 16.2A summary 1LSM 16.2A summary 1