Download Word (docx):

Navigate using audio

Clicker 1

  • Audio 0:00:38.000666
  • Give the net ionic equation for the reaction (if any) that occurs when aqueous solutions of Na2CO3 and HCl are mixed
    • A) 2H+(aq)+CO3 2-(aq) → H2CO3(s)
    • B) 2Na+(aq)+CO3 2-(aq)+2H+(aq) + 2Cl- (aq) → H2CO3(s)+2NaCl(aq)
    • C) 2H+(aq)+CO3 2-(aq) → H2O(l)+CO2(g)
    • D) 2Na+(aq)+CO3 2-(aq)+2H+(aq)+2Cl- (aq)→H2CO3(s)+2Na+(aq)+2Cl- (aq)
    • E) No reaction occurs.

How to Name an Oxyacid

  • Audio 0:03:09.986990
  • If a polyatomic ion name ends in
    • –ate, then change the ending to a
    • –ic suffix.
    • Example:
      • NO3 − is the nitrate ion, so it would become nitric.
  • If a polyatomic ion name ends in
    • –ite, then change the ending to a
    • –ous suffix.
    • Example:
      • SO3 2− is the sulfite ion, so it would become sulfurous.
  • Finally, write the word acid at the end of all names.

Practice Naming Acids

  • Audio 0:04:58.589530
    1. H2S
      • Hydrosulfuric acid
    2. HClO3
      • chloric acid
    3. HC2H3O2
      • acetic acid

Clicker 2

  • What is the name for an aqueous solution of HIO
    • A) hydroiodic acid
    • B) hypoiodous acid
    • C) iodous acid
    • D) iodic acid
    • E) periodic acid

Acid–Base Chemical Reactions

  • Audio 0:08:22.756094
  • Audio 0:12:28.774412
  • Acid–Base Reaction:
    • An acid reacts with a base producing water (or in some cases a weak electrolyte) and a salt.
    • An acid–base reaction is also called a neutralization reaction.
  • In acid–base reactions, as in precipitation reactions, the reactions occur when the anion from one reactant combines with the cation of the other.

Acid–Base Reactions

  • Audio 0:13:19.839427
  • When an acid and base react, the reaction is called a neutralization reaction.
    • Example:
      • 2 HNO3(aq) + Ca(OH)2(aq) → Ca(NO3)2(aq) + 2 H2O(l)
  • As long as the salt that forms is soluble in water, the net ionic equation for an acid–base reaction is:
    • H+(aq) + OH–(aq) → H2O(l)
  • A neutralization reaction is completed when the moles of acid equal the moles of base in the solution.
    • Moles of acid = Moles of base
  • A neutralization reaction does not always mean that the pH of the solution is 7.

Acids and Bases in Solution

  • Audio 0:16:36.637260
  • Acids ionize in water to form H+ ions; more precisely, the H from the acid molecule is donated to a water molecule to form hydronium ion, H3O+.
  • Most chemists use H+ and H3O+ interchangeably.
  • Bases dissociate in water to form OH– ions.
    • Bases, such as NH3, that do not contain OH– ions produce OH– by pulling H off water molecules.
  • In the reaction of an acid with a base, the H+ from the acid combines with the OH– from the base to make water. – The cation from the base combines with the anion from the acid to make the salt.

Acid–Base Reaction

  • HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)
  • The reaction of hydrochloric acid (acid) and sodium hydroxide (base) forms sodium chloride (soluble salt) and water.

Predict the Product of Acid–Base Reactions

  • HCl(aq) + Ba(OH)2(aq) → ?
  • (H+ + Cl−) + (Ba2+ + OH−) → (H+ + OH−) + (Ba2+ + Cl−)
    • HCl(aq) + Ba(OH)2(aq) → H2O(l) + BaCl2
    • 2 HCl(aq) + Ba(OH)2(aq) → 2 H2O(l) + BaCl2(aq)

Predict the Product of Acid–Base Reactions

  • Audio 0:18:17.410585
  • H2SO4(aq) + LiOH(aq) → ?
  • (H+ + SO4 2−) + (Li+ + OH−) → (H+ + OH−) + (Li+ + SO4 2−)
    • H2SO4(aq) + LiOH(aq) → H2O(l) + Li2SO4
    • H2SO4(aq) + 2 LiOH(aq) → 2 H2O(l) + Li2SO4(aq)

Clicker 3

  • Audio 0:21:18.340305
  • Which of the following is an acid-base reaction?
    • A) C(s) + O2(g) → CO2(g)
    • B) 2 HClO4(aq) + Ca(OH)2(aq) → 2 H2O(l) + Ca(ClO4)2(aq)
    • C) Fe(s) + 2 AgNO3(aq) → 2 Ag(s) + Fe(NO3)2(aq)
    • D) MgSO4(aq) + Ba(NO3)2(aq) → Mg(NO3)2(aq) + BaSO4(s)
    • E) None of the above are acid base reactions.

Acid–Base Titrations

  • Audio 0:21:37.385327
  • This is a problem because some things can not be legally put down the sink and it depends on the acidity
  • In a titration, a substance in a solution of known concentration is reacted with another substance in a solution of unknown concentration.
  • When exactly enough solution has been added the reactants are in their stoichiometric ratio. Called the equivalence point
    • The solution of known concentration is added slowly from an instrument called a burette.
      • A long glass tube with precise volume markings that allows small additions of solution
  • The titrant is the solution in the burette.

Acid–Base Titrations

  • Audio 0:25:27.198386
  • In acid–base titrations, because both the reactant and product solutions are colorless, a chemical is added that changes color when the solution undergoes large changes in acidity/alkalinity.
    • The chemical is called an indicator.
  • The endpoint of a reaction is when the indicator color changes.
  • The endpoint of an acid–base titration is where the number of moles of H+ equals the number of moles of OH–.
    • This is known as the equivalence point.

Acid–Base Titration

  • Audio 0:26:39.290296

Titration

  • In this titration, NaOH is added to a dilute HCl solution. When the NaOH and HCl reach stoichiometric proportions (the equivalence point), the indicator changes color to pink.

Practice Problem: Acid–Base Titration

  • Audio 0:32:01.268341
  • The titration of a 10.00 mL sample of HCL solution of unknown concentration requires 12.54 ml of a 0.100 M NaOH solution to reach the equivalence point. What is the concentration of the unknown HCl solution in M?

Clicker 4

  • Audio 0:33:40.733664
  • The titration of 25.0 mL of an unknown concentration of H2SO4 solution requires 83.6 mL of 0.12 M LiOH solution. What is the concentration of the H2SO4 solution?
    • A) 0.20 M
    • B) 0.40 M
    • C) 0.10 M
    • D) 0.36 M
    • E) 0.25 M

Gas-Evolution Chemical Reactions

  • Audio 0:41:08.439627
  • In a gas-evolution reaction, a gas forms, resulting in bubbling.
  • In both acid–base and gas-evolution reactions, as in precipitation reactions, the reactions occur when the anion from one reactant combines with the cation of the other.
    • Many gas-evolution reactions are also acid– base reactions.

Example of Gas-Evolution Reactions

  • Audio 0:42:31.119388
  • Some reactions form a gas directly from the ion exchange.
    • K2S(aq) + H2SO4(aq) → K2SO4(aq) + H2S(g)
  • Other reactions form a gas by the decomposition of one of the ion exchange products into a gas and water.
    • NaHCO3(aq) + HCl(aq) → NaCl(aq) + H2CO3(aq)
    • H2CO3(aq) → H2O(l) + CO2(g)

Gas-Evolution Reaction

  • Audio 0:44:17.526266
  • NaHCO3(aq) + HCl(aq) H2O(l) + NaCl(aq) + CO2(g)
  • When aqueous sodium bicarbonate is mixed with aqueous hydrochloric acid, gaseous CO2 bubbles are the result of the reaction.

Types of Compounds That Undergo GasEvolution Reactions

  • Audio 0:44:59.297799