Chapter 14

weak acid

- An acid that releases few hydrogen ions in aqueous solution. - The aqueous solution of a weak acid contains hydronium ions, anions, and dissolved acid molecules. Hydrocyanic acid is an example of a weak acid.

strong acid

- is one that ionizes COMPLETELY in aqueous solution. - is a strong electrolyte. - Perchloric acid, HClO4, hydrochloric acid, HCl, and nitric acid, HNO3, are examples of strong acids. - In water, 100% of the acid molecules are ionized. The strength of an acid depends on the polarity of the bond between hydrogen and the element to which it is bonded and the ease with which that bond can be broken. - Acid strength increases with increasing polarity and decreasing bond energy.

bases List five general properties of...

1. Aqueous solutions of bases taste bitter. 2. Bases change the color of acid-base indicators. 3. Dilute aqueous solutions of bases feel slippery. (ex: wash w soap) 4. Bases react with acids to produce salts and water. (The properties of a base disappear with the addition of an equivalent amount of an acid. It could also be said that "neutralization" of the base occurs when these two substances react to produce a salt and water.) 5. Bases conduct electric current. (thus electrolytes)

aqueous acids List five general properties of...

1. have a sour taste. 2. change the color of acid-base indicators. 3. Some acids react with active metals and release hydrogen gas, H2. EX: Hydrogen gas is formed as a product, as shown by the reaction of barium with sulfuric acid. Ba(s) + H2SO4(aq) ⎯→ BaSO4(s) + H2(g) 4. Acids react with bases to produce salts and water. (When chemically equivalent amounts of acids and bases react, the three properties just described disappear because the acid is "neutralized." The reaction products are water and an ionic compound called a salt.) 5. Acids conduct electric current. (Some acids completely separate into ions in water and are strong electrolytes. Other acids are weak electrolytes.)

monoprotic acid.

An acid that can donate only one proton (hydrogen ion) per molecule Hydrochloric acid, HCl, is a strong monoprotic acid

Strong Acid-Strong Base Neutralization

An acid-base reaction occurs in aqueous solution between hydro- chloric acid, a strong acid that completely ionizes to produce H3O+, and sodium hydroxide, a strong base that completely dissociates to pro- duce OH−. The formula equation for this reaction is written as follows. HCl(aq) + NaOH(aq) ⎯→ NaCl(aq) + H2O(l)

Question (section 2): Label each reactant in the reaction below as a proton donor or a proton acceptor and as acidic or basic. _ H2CO3 +H2O----->HCO3−+H3O+ <-----

H2CO3: proton donor, acidic H2O: proton acceptor, basic

Question (section 3): Consider the equation for acetic acid plus water. CH3COOH + H2O ⎯→ CH3COO- + H3O+ Refer to Table 6 to compare the strengths of the two acids in the equation. Do the same for the two bases.

H3O+ is the stronger acid; CH3COO- is the stronger base

Question (section 1): is every strong electrolyte also a strong acid

NO , materials other than acids can iodize in aqueous solution.

Question (section 2): For the following three reactions, identify the reactants that are Arrhenius bases, Brønsted-Lowry bases, and/or Lewis bases. State which type(s) of bases each reactant is. Explain your answers. a. NaOH(s) ⎯→ Na+(aq) + OH−(aq) b. HF(aq) + H2O(l) ⎯→ F−(aq) + H3O+(aq) c. H (aq) + NH3(aq) ⎯→ NH4(aq)

NaOH, an Arrhenius base H2O, a Bonsted-Lowry, and Lewis base NH3, a Bonsted-Lowry, and Lewis base

Question (section 3): Explain how the presence of several oxygen atoms in a compound containing an −OH group can make the compound acidic.

Oxygen atoms draw electron density away from the O-H bond, making it more color (more easily broken).

Question (section 3): Consider the equation for acetic acid plus water. CH3COOH + H2O ⎯→ CH3COO- + H3O+ Determine which direction—forward or reverse—is favored in the reaction.

Reverse reaction is favored

binary nomenclature

SEE SEPARATE PAPER

oxyacids and their chemical formulas.

SEE SEPARATE PAPER

binary acids (common) and their chemical formulas.

SEE SEPARTE PAPER

Question (section 1): Why are strong acids also strong electrolytes?

Strong acids ionize completely in an aqueous solution

strong/weak bases

Strong bases dissociate completely in aqueous solutions, whereas weak acids and bases dissociate partially. Potassium hydroxide, KOH, is a strong base Ammonia is a weak base

conjugate acid

The species that is formed when a Brønsted-Lowry base gains a proton

Question (section 3): Complete and balance the equations for the following acid-base reactions: a. H2CO3 + Sr(OH)2 ⎯→ b. HCIO4 + NaOH ⎯→ c. HBr + Ba(OH)2 ⎯→ d. NaHCO3 + H2SO4 ⎯→

a. H2CO3 + Sr(OH)2 ⎯→ SrCO3 + 2H2O b. HCIO4 + NaOH ⎯→ NaClO4 + H2O c. HBr + Ba(OH)2 ⎯→ BaBr2 + 2H2O d. NaHCO3 + H2SO4 ⎯→ Na2SO4 +2H2O + 2CO2

triprotic acid

an acid able to donate three protons per molecule Phosphoric acid is the type of polyprotic acid

diprotic acid

an acid that can donate two protons per molecule Sulfuric acid, H2SO4, is a strong diprotic acid

binary acid

an acid that contains only two different elements: hydrogen and one of the more electronegative elements. The hydrogen halides—HF, HCl, HBr, and HI—are all binary acids.

Lewis acid

an atom, ion, or molecule that ACCEPTS an electron pair to form a covalent bond

Lewis base

an atom, ion, or molecule that DONATES an electron pair to form a covalent bond

Amphoteric

any species that can react as either an acid or a base

HBrO3

bromic acid

Organic acids which contain the acidic carboxyl group —COOH are weak or strong acids?

generally weak acids.

Bases examples

household ammonia milk of magnesia antacids lye

HBrO

hypobromous acid

Arrhenius acid

is a chemical compound that increases the concentration of hydrogen ions, H+, in aqueous solution. In other words, an acid will ionize in solution, increasing the number of hydrogen ions present.

Brønsted-Lowry base

is a molecule or ion that is a proton acceptor

Brønsted-Lowry acid

is a molecule or ion that is a proton donor

Arrhenius base

is a substance that increases the concentration of hydroxide ions, OH−, in aqueous solution. Some bases are ionic hydroxides. These bases dissociate in solution to release hydroxide ions into the solution. Other bases are substances that react with water to remove a hydrogen ion, leaving hydroxide ions in the solution.

polyprotic acid

is an acid that can donate more than one proton per molecule. Sulfuric acid, H2SO4, and phosphoric acid, H3PO4, are examples of polyprotic acids.

salt

is an ionic compound composed of a cation from a base and an anion from an acid.

Brønsted-Lowry acid-base reaction

protons are transferred from one reactant (the acid) to another (the base)

Lewis acid-base reaction

the formation of one or more covalent bonds between an electron-pair donor and an electron-pair acceptor

Neutralization

the reaction of hydronium ions and hydroxide ions to form water molecules.

conjugate base

the species that remains after a Brønsted-Lowry acid has given up a proton

Conjugate acids and bases

the stronger an acid is, the weaker its conjugate base; the stronger a base is, the weaker its conjugate acid.

Acids examples

vinegar soft drinks sour milk fruits fruit juices muriatic acid