acids , bases , & salts
DESCRIPTION
ACIDS , BASES , & SALTS. Properties of Acids. Sour taste Electrolytes: - aq solns that conduct electric current React with bases to form water and salt (Neutralization Reaction) React with most metals to produce H 2 (g) Aci d s turn litmus re d. Electrolyte. - PowerPoint PPT PresentationTRANSCRIPT
ACIDSACIDS, BASESBASES, & SALTS
Properties of AcidsAcids1. Sour taste2. Electrolytes:
- aq solns that conduct electric current
3. React with bases to form water and salt (Neutralization Reaction)
4. React with most metals to produce H2(g)
5. Acidds turn litmus redd
ElectrolyteElectrolyte
• Substance when dissolved in H2O produces soln that conducts electric current– Separate into ions in aq soln
• Acids, bases, & salts are electrolytes
MgClMgCl22(s) (s) Mg Mg+2+2(aq) + 2Cl(aq) + 2Cl-1-1(aq)(aq)
Can metals react with acids?Can metals react with acids?
• See Table JTable J
• All metals above H2 react with acids
–SR reactions
• Cu, Ag, and AuCu, Ag, and Au do notnot react with acids
2HCl + Mg 2HCl + Mg
• Mg above H2 so reaction proceeds
• Single replacement reaction
MgClMgCl22 + H + H22
Properties of BasesBases
1. Bitter taste2. Slippery or soapy feeling3. Electrolytes4. React with acids to produce
water and salt5.5. BBases turn litmus bblue
Formulas of AcidsFormulas of Acids
• Format: HHX where X = nonmetal (F, Cl, Br, I) or or X = negative polyatomic ion Exception: H2O2
• Some acids have 2 or 3 HH’s–Ex: HHF, HH2S, HH3PO4
Formulas ofFormulas of BasesBases
• Format: MFormat: MOHOH
where M is metalwhere M is metal •Ex: NaOHOH, Ca(OHOH)2
• Exception: NH3 and NH4+1
• CH3OH is NOTNOT a base. WHY?WHY?
Identify the Electrolytes• NaClNaCl
• CC22HH55OHOH
• HH22SOSO44
• NaOHNaOH
• CC66HH1212OO66
• CaICaI22
• HFHF
• Mg(OH)Mg(OH)22
• CC33HH77OHOH
• CClCCl44
• HNOHNO33
• CC55HH1212
• KK33POPO44
• CHCH33OCHOCH33
• LiOHLiOH
• HIHI
• (NH(NH44))22SOSO44
• CC1212HH2222OO1111
Yes - SYes - S
Yes - SYes - S
Yes - SYes - S
Yes - BYes - B
NONO
NONO
NONO
NONO
NONO
NONO
NONO
Yes - Yes - AA
Yes - BYes - B
Yes - Yes - AA
Yes - BYes - B
Yes - Yes - AA
Yes - BYes - B
Yes - Yes - AA
Acid, Base, or Neutral?
• all HH22O contains some HO contains some H+1+1 & some OH & some OH-1 -1 ionsions–pure H2O: concentrations very low
• Neutral solution: [HNeutral solution: [H+1+1] = [OH] = [OH-1-1]]
• Acidic solution: HAcidic solution: H+1+1 > OH > OH-1-1
• Basic solution: OHBasic solution: OH-1-1 > H > H+1+1
Water & self-ionizationWater & self-ionization
• H2O(l) + H2O(l) H3O+1(aq) + OH-1(aq)
HH33OO+1 +1 = hydronium ion
OHOH-1-1 = = hydroxide ion
• H2O(l) H+1(aq) + OH-1(aq)
H+1 and H3O+1 used interchangeably
HH+1+1 called proton or hydrogen ion
Self-ionization of waterSelf-ionization of water
Arrhenius AcidArrhenius Acid• Substance that contains hydrogen & Substance that contains hydrogen &
ionizes to produce Hionizes to produce H+1+1 ions in aqueous ions in aqueous solutionsolution
HCl(g) + H2O(l) HH+1+1(aq) + Cl-1(aq)
HNO3 + H2O(l) HH+1+1(aq) + NO3-1(aq)
Arrhenius BaseArrhenius Base
• substance that contains hydroxide substance that contains hydroxide group & ionizes to produce OHgroup & ionizes to produce OH-1-1 ions in aqueous solutionions in aqueous solution
NaOH(s) Na+1(aq) + OHOH-1-1(aq)
Arrhenius SaltArrhenius Salt
• Electrolytes where HElectrolytes where H+1+1 notnot only only positive ion and OHpositive ion and OH-1-1 notnot only only negative ion formed in aqueous negative ion formed in aqueous solutionsolution
Ex: NaCl, CaBr2,KNO3, NH4I
Salts in Water (ionic compounds)
• NaCl(s) + H2O(l) Na+1(aq) + Cl-1(aq)
• CaBr2(s) + H2O(l) Ca+2(aq) + 2Br-1(aq)
• Al(NO3)3(s) + H2O(l) Al+3(aq) + 3NO3-1(aq)
Arrhenius Model has limitationsArrhenius Model has limitations
• Don’t always use HH22O as solventO as solvent
– Arrhenius model only applies whenonly applies when H2O is solvent
• Doesn’t explain all cases:– NH3 (base) doesn’t contain OH-1 but it produces
OH-1
Alternate Theory: Bronsted-Alternate Theory: Bronsted-LowryLowry
• Acid = a proton donorAcid = a proton donor• All Arrhenius acids = Bronsted-Lowry All Arrhenius acids = Bronsted-Lowry
AcidsAcids
HX(g) + H2O(l) H3O+1 + X-1
HH+1+1 forms molecule-ion bond with water molecule HH33OO+1+1 (hydronium ion)hydronium ion)
Bronsted-Lowry Acids
• HCl + H2O H3O+1 + Cl-1
• HNO3 + H2O H3O+1 + NO3-1
• H2SO4 + H2O H3O+1 + HSO4-1
• H2O + HSO4-1 H3O+1 + SO4
-2
Bronsted-Lowry BaseBronsted-Lowry Base• Base = proton acceptorBase = proton acceptor
OH-1 is base
• Not restricted to aqueous solutionNot restricted to aqueous solution
NH3 + H2O NH4+1 + OH-1
NHNH33 is a base! is a base!
Bronsted-Lowry Acids & BasesBronsted-Lowry Acids & Bases
AmphotericAmphoteric
• Substance that acts as Substance that acts as both acid & baseboth acid & base
Water is amphoteric!Water is amphoteric!
HX(g) + H2O(l) H3O+1 + X-1 (base)
NH3 + HH22OO NH4+1 + OH-1
(acid)(acid)
Naming Acids & Bases
Naming Binary AcidsNaming Binary Acids
• Hydro + stem of nonmetal + icHydro + stem of nonmetal + ic
HF = ?
HCl = ?
H2S = ?
Hydrofluoric acidHydrofluoric acid
Hydrochloric acidHydrochloric acid
Hydrosulfic acidHydrosulfic acid
Naming Ternary Acids
• Name derived from polyatomicpolyatomic anion (see Table E)
• Replace –iteite with –ousous, add acid
HNOHNO22 • Replace –ateate with –icic, add, add acid
HNOHNO33
nitrous acidnitrous acid
nitric acidnitric acid
Ternary AcidsTernary Acids
polyatomics with S and P, make stem long againpolyatomics with S and P, make stem long again
– HH33POPO44 = phosphoric acid, not phosphic acid = phosphoric acid, not phosphic acid
– HH22SOSO44 = sulfuric acid, not sulfic acid = sulfuric acid, not sulfic acid
– HH22SOSO33 = sulfurous acid, not sulfous acid = sulfurous acid, not sulfous acid
•SEE TABLE KSEE TABLE K
NamingNaming BasesBases
• Name the metal + hydroxideName the metal + hydroxide
NaOH = ?
Ca(OH)2 = ?
Mg(OH)2 = ?
Sodium hydroxideSodium hydroxide
Calcium hydroxideCalcium hydroxide
Magnesium hydroxideMagnesium hydroxide