Chemistry Chapter 14 - Acids and Bases

Write separate equations representing the reaction of H2PO4−H2PO4− (a) as a base with HBr (b) as an acid with OH−

(a) H2PO4−(aq)+HBr(aq)⇌H3PO4(aq)+Br−(aq);H2PO4−(aq)+HBr(aq)⇌H3PO4(aq)+Br−(aq); (b) H2PO4−(aq)+OH−(aq)⇌HPO42−(aq)+H2O(l)

Write separate equations representing the reaction of HSO3−HSO3− (a) as an acid with OH− (b) as a base with HI

(a) HSO3−(aq)+OH−(aq)⇌SO32−(aq)+H2O(l)HSO3−(aq)+OH−(aq)⇌SO32−(aq)+H2O(l) (b) HSO3−(aq)+HI(aq)⇌H2SO3(aq)+I−(aq)

If a neutral acid donates a proton, the conjugate base will have a charge of _______.

-1

A solution has a hydroxide ion concentration of 1.9*10^-3. What is the pH of this solution? The pH of human A blood is 7.40. What is the hydronium ion concentration?

1. 11.28, 2. 4.0*10^-8

A sample of orange juice has a hydronium ion concentration of 2.9*10^-4 M. What is the pH? What is the pH of stomach acid, a solution of HCl with hydronium ion concentrations of 1.20*10^-3 M.

1. 2 sig figs, 3.54 2. 2.92

Consider a solution of hydrobromic acid with hydronium ion concentrations of 1.50*10^-3. Calculate the pH, pOH, and OH- concentration.

1. 2.824 2. 11.176 3. 6.67*10^-12

Nomenclature of Binary Acids HBr, H2S

Hydrobromic acid, Hydrosulfuric Acid

Nomenclature of Polyatomic Ions + What is oxo acid? NO3-, HNO2, H2SO3

Oxo acids - Acids that contain oxygen Polyatomic: Nitrate, Nitric Acid, Sulfurous Acid

Which of the following are not amphiprotic? Select all that apply. NH3 PO3−4 H2SO4 H2O

PO3−4 H2SO4

A solution containing 572.0mL of 0.6300MHCl is diluted to a volume of 1.000L. What is the pH of this solution?

0.4432

As temperature increases, the pH of a sample of pure water will: decrease increase stay the same impossible to predict

decrease

Identify the option below that is a characteristic of acidic solutions. [H3O+]<[OH−] pOH levels greater than 7 at 25∘C pOH levels less than 7 at 25∘C pOH levels of 7 at 25∘C

pOH levels greater than 7 at 25∘C

the ion-product constant for water

the ion-product constant for water, Kw: 1*10^-14

Bronsted-Lowry acid + Bronsted-Lowry base

A compound that donates a proton to another compound and a compound that accepts a proton from another compound.

Arrhenius Bases (what they are, taste, dissolve with, form, and can be)

Increase OH- ions when dissolved in pure water. Bitter tasting/slippery. Are the oxides and hydroxides of metals.. Reacts with acids to form salts. Can be - Ionic Compounds that contain OH- - Molecules (Primarily amines) - Anions with H or without H - Cation (few)

Arrhenius Acids (what they are, taste, dissolve with, form, and can be)

Increase hydrogen ions when dissolved in pure water. Sour tasting. Dissolves with metals to form salts. Reacts with bases or alkalis to form salts. Can be - Molecules (Organic and inorganic) - Cations, Anions with H

acid ionization constant

Ka = [products]/[reactants] (No liquid) - Equilibrium constant for acid

base ionization constant

Kb = [products]/[reactants] (No liquid) - Equilibrium constant for bases

Strongest Bases

LiOH, NaOH, KOH, Ca(OH)2, Sr(OH)2, Ba(OH)2

What is the conjugate base of NH3? Please use subscripts for the number of atoms and superscript for the charge when writing the chemical formula, if needed.

NH2-

What will determine the number of moles of hydronium in an aqueous solution of a strong monoprotic acid? The strength of the acid. The amount of acid that was added. The total amount of aqueous ions in the resulting aqueous solution. The volume of the solution.

The amount of acid that was added.

Conjugate Acid and Conjugate Base

When an acid donates H+, the species that remains is called the conjugate base of the acid because it reacts as a proton acceptor in the reverse reaction. Likewise, when a base accepts H+, it is converted to its conjugate acid. The

A solution that has a greater hydroxide concentration than hydronium concentration will be: acidic basic neutral depends on the solution

basic

Which of the following is NOT a strong acid? Perfect. Your hard work is paying off 😀 hydrobromic acid hydroiodic acid hydrochloric acid hydrofluoric acid

hydrofluoric acid

As temperature increases, Kw will:

increase

A basic solution is 1.35×10−5M in calcium hydroxide, Ca(OH)2. What is the pH of the solution at 25.0∘C? pH=4.57 pH=9.43 pH=4.87 pH=9.13

pH=9.43

The hydronium ion concentration of vinegar is approximately 4 ×× 10−3 M. What are the corresponding values of pOH and pH?

pOH = 11.6, pH = 2.4

Roughly how many water molecules are ionized at any given time in a sample of room-temperature water? two in a thousand two in a million two in a billion two in a trillion

two in a billion

The concentrations of OH- and H3O in pure water are both ___

1.0*10^-7

What are the hydronium ion concentration and the hydroxide ion concentration in pure water at 25 °C?

1.0×10^−7M

What is the hydronium ion concentration in a solution of pH 10.90?

1.3*10^-11

Suppose that the hydronium ion concentration of an aqueous solution at 25∘C is 8.0×10−10 M. What is the hydroxide ion concentration of the solution? Your answer should include two significant figures. Write your answer in scientific notation. Use the multiplication symbol rather than the letter x in your answer.

1.3*10^-5

What are the pOH and the pH of a 0.0125-M solution of potassium hydroxide, KOH?

1.903

The hydronium concentration of a solution is equal to: -logpH logpH 10-pH 10pH

10-pH

A 1.3×10−6mol sample of Sr(OH)2 is dissolved in water to make up 25.0 mL of solution. What is the pH of the solution at 25.0∘C? 4.08 10.02 9.61 8.31

10.02

A 4.28×10−5mol sample of barium hydroxide, Ba(OH)2, is dissolved in water to make up 0.350L of solution. What is the pH of the solution at 25.0∘C? Round the answer to three significant figures. 10.1 3.61 9.63 10.4

10.4

What are amphiprotic species? Illustrate with suitable equations.

11 . Amphiprotic species may either gain or lose a proton in a chemical reaction, thus acting as a base or an acid. An example is H2O. As an acid: H2O(aq)+NH3(aq)⇌NH4+(aq)+OH−(aq).H2O(aq)+NH3(aq)⇌NH4+(aq)+OH−(aq). As a base: H2O(aq)+HCl(aq)⇌H3O+(aq)+Cl−(aq)H2O(aq)+HCl(aq)⇌H3O+(aq)+Cl−(aq)

Calculate the hydronium ion concentration of a solution with a pH of −1.07.

12 M

A 7.12×10−4mol sample of KOH is dissolved in water to make up 50.0mL of solution. What is the pH of the solution at 25.0∘C? Round the answer to three significant figures. Great work! That's correct. 12.2 1.85 15.85 10.9

12.2

State which of the following species are amphiprotic and write chemical equations illustrating the amphiprotic character of these species. (a) NH3 (b) HPO4−HPO4− (c) Br− (d) NH4+NH4+ (e) ASO43−

13 . amphiprotic: (a) NH3+H3O+⟶NH4OH+H2O,NH3+H3O+⟶NH4OH+H2O, NH3+OCH3−⟶NH2−+CH3OH;NH3+OCH3−⟶NH2−+CH3OH; (b) HPO42−+OH−⟶PO43−+H2O,HPO42−+OH−⟶PO43−+H2O, HPO42−+HClO4⟶H2PO4−+ClO4−;HPO42−+HClO4⟶H2PO4−+ClO4−; not amphiprotic: (c) Br−; (d) NH4+;NH4+; (e) AsO43−

Which two equations ONLY apply to room temp?

14 = pH+pOH kw = (H+)(OH-) = 1.0*10^-14

The ionization constant for water (Kw) is 9.311 ×× 10−14 at 60 °C. Calculate [H3O+], [OH−], pH, and pOH for pure water at 60 °C.

17 . x = 3.051 ×× 10−7 M = [H3O+] = [OH−]; pH = −log3.051 ×× 10−7 = −(−6.5156) = 6.5156; pOH = pH = 6.5156

Calculate the pH and the pOH of each of the following solutions at 25 °C for which the substances ionize completely: (a) 0.000259 M HClO4 (b) 0.21 M NaOH (c) 0.000071 M Ba(OH)2 (d) 2.5 M KOH

19 . (a) pH = 3.587; pOH = 10.413; (b) pOH = 0.68; pH = 13.32; (c) pOH = 3.85; pH = 10.15; (d) pOH = −0.40; pH = 14.4

What is the hydronium ion concentration in an aqueous solution with a hydroxide ion concentration of 0.001 M at 25∘C?

1×10−11 M

A solution of an acid in water has a hydroxide ion concentration of 3.5×10−6. What is the concentration of hydronium at 25∘C? Your answer should include two significant figures. Write your answer in scientific notation. Use the multiplication symbol rather than the letter x in your answer.

2.9*10^-9

What is the pH of stomach acid, a solution of HCl with a hydronium ion concentration of 1.2 × 10^-3 M?

2.92

What are the hydronium and hydroxide ion concentrations in a solution whose pH is 6.52?

21 . [H3O+] = 3.0 ×× 10−7 M; [OH−] = 3.3 ×× 10−8 M

. The hydroxide ion concentration in household ammonia is 3.2 ×× 10−3 M at 25 °C. What is the concentration of hydronium ions in the solution?

25 . [OH−] = 3.1 ×× 10−12 M

The odor of vinegar is due to the presence of acetic acid, CH3CO2H, a weak acid. List, in order of descending concentration, all of the ionic and molecular species present in a 1-M aqueous solution of this acid.

29 . [H2O] > [CH3CO2H] > [H3O+][H3O+] ≈ [CH3CO2−][CH3CO2−] > [OH−]

Calculate the hydronium ion concentration of blood, the pH of which is 7.3.

=5×10−8M

. Show by suitable net ionic equations that each of the following species can act as a Brønsted-Lowry acid: (a) H3O+H3O+ (b) HCl (c) NH3 (d) CH3CO2H (e) NH4+NH4+ (f) HSO4−

3 . (a) H3O+(aq)⟶H+(aq)+H2O(l);H3O+(aq)⟶H+(aq)+H2O(l); (b) HCl(aq)⟶H+(aq)+Cl−(aq);HCl(aq)⟶H+(aq)+Cl−(aq); (c) NH3(aq)⟶H+(aq)+NH2−(aq);NH3(aq)⟶H+(aq)+NH2−(aq); (d) CH3CO2H(aq)⟶H+(aq)+CH3CO2−(aq);CH3CO2H(aq)⟶H+(aq)+CH3CO2−(aq); (e) NH4+(aq)⟶H+(aq)+NH3(aq);NH4+(aq)⟶H+(aq)+NH3(aq); (f) HSO4−(aq)⟶H+(aq)+SO42−(aq)HSO4−(aq)⟶H+(aq)+SO42−(aq)

An aqueous solution at 25∘C has a hydronium ion concentration of 3.2×10−9 M. What is the hydroxide ion concentration of the solution? Write your answer in scientific notation. Use the multiplication symbol rather than the letter x in your answer. Report your answer two significant figures

3.1*10^-6

. The hydroxide ion concentration in household ammonia is 3.2 ×× 10−3 M at 25 °C. What is the concentration of hydronium ions in the solution?

3.125 x 10^-12 m.

Suppose that the hydroxide ion concentration of an aqueous solution at 25∘C is 2.8×10−7 M. What is the hydronium ion concentration of the solution? Your answer should include two significant figures. Write your answer in scientific notation. Use the multiplication symbol rather than the letter x in your answer.

3.6*10^-8

Explain why the ionization constant, Ka, for H2SO4 is larger than the ionization constant for H2SO3.

31 . The oxidation state of the sulfur in H2SO4 is greater than the oxidation state of the sulfur in H2SO3.

Gastric juice, the digestive fluid produced in the stomach, contains hydrochloric acid, HCl. Milk of Magnesia, a suspension of solid Mg(OH)2 in an aqueous medium, is sometimes used to neutralize excess stomach acid. Write a complete balanced equation for the neutralization reaction, and identify the conjugate acid-base pairs.

33 . Mg(OH)2(s)+BB2HCl(aq)BA⟶Mg2+(aq)+2Cl−(aq)+CB2H2O(l)CAMg(OH)2(s)+2HCl(aq)⟶Mg2+(aq)+2Cl−(aq)+2H2O(l)BBBACBCA

What is the ionization constant at 25 °C for the weak acid CH3NH3+,CH3NH3+, the conjugate acid of the weak base CH3NH2, Kb = 4.4 ×× 10−4.

35 . Ka=2.3×10−11Ka=2.3×10−11

Which base, CH3NH2 or (CH3)2NH, is the stronger base? Which conjugate acid, (CH3)2NH2+(CH3)2NH2+ or CH3NH3+CH3NH3+, is the stronger acid?

37 . The stronger base or stronger acid is the one with the larger Kb or Ka, respectively. In these two examples, they are (CH3)2NH and CH3NH3+.CH3NH3+.

. Show by suitable net ionic equations that each of the following species can act as a Brønsted-Lowry base: (a) H2O (b) OH− (c) NH3 (d) CN− (e) S2− (f) H2PO4−

5 . (a) H2O(l)+H+(aq)⟶H3O+(aq);H2O(l)+H+(aq)⟶H3O+(aq); (b) OH−(aq)+H+(aq)⟶H2O(l);OH−(aq)+H+(aq)⟶H2O(l); (c) NH3(aq)+H+(aq)⟶NH4+(aq);NH3(aq)+H+(aq)⟶NH4+(aq); (d) CN−(aq)+H+(aq)⟶HCN(aq);CN−(aq)+H+(aq)⟶HCN(aq); (e) S2−(aq)+H+(aq)⟶HS−(aq);S2−(aq)+H+(aq)⟶HS−(aq); (f) H2PO4−(aq)+H+(aq)⟶H3PO4(aq)H2PO4−(aq)+H+(aq)⟶H3PO4(aq)

A solution of an acid in water has a hydronium ion concentration of 2.0 ×× 10−6 M. What is the concentration of hydroxide ion at 25 °C?

5.0*10^-9

What is the hydroxide ion concentration in a solution of pH 3.71? Remember to report your answer with the correct number of significant figures.

5.1*10^-11

A solution has a pH of 7.5 at 50∘C. What is the pOH of the solution given that Kw=8.48×10−14 at this temperature?

5.6

Water exposed to air contains carbonic acid, H2CO3, due to the reaction between carbon dioxide and water: CO2(aq)+H2O(l)⇌H2CO3(aq)CO2(aq)+H2O(l)⇌H2CO3(aq) Air-saturated water has a hydronium ion concentration caused by the dissolved CO2 of 2.0 ×× 10−6 M, about 20-times larger than that of pure water. Calculate the pH of the solution at 25 °C.

5.70

What is the conjugate acid of each of the following? What is the conjugate base of each? (a) OH− (b) H2O (c) HCO3−HCO3− (d) NH3 (e) HSO4−HSO4− (f) H2O2 (g) HS− (h) H5N2+

7 . (a) H2O, O2−; (b) H3O+, OH−; (c) H2CO3, CO32−;CO32−; (d) NH4+,NH4+, NH2−;NH2−; (e) H2SO4, SO42−;SO42−; (f) H3O2+,H3O2+, HO2−;HO2−; (g) H2S; S2−; (h) H6N22+,H6N22+, H4N2

At a particular temperature, a sample of pure water has a Kw of 5.1×10−11. What is the hydronium concentration of this sample? Your answer should include two significant figures. Report your answer in scientific notation. Use the multiplication symbol rather than the letter x in your answer.

7.1*10^-6

A solution has a pOH of 7.1 at 10∘C. What is the pH of the solution given that Kw=2.93×10−15 at this temperature? Remember to report your answer with the correct number of significant figures.

7.4

What is the pOH of a solution with [OH−]=3.44×10−8 M? Report your answer using the correct number of significant figures. Note that when taking the log of a value, keep as many decimal places in the result as there are significant figures in the value.

7.463

. Identify and label the Brønsted-Lowry acid, its conjugate base, the Brønsted-Lowry base, and its conjugate acid in each of the following equations: (a) HNO3+H2O⟶H3O++NO3−HNO3+H2O⟶H3O++NO3− (b) CN−+H2O⟶HCN+OH−CN−+H2O⟶HCN+OH− (c) H2SO4+Cl−⟶HCl+HSO4−H2SO4+Cl−⟶HCl+HSO4− (d) HSO4−+OH−⟶SO42−+H2OHSO4−+OH−⟶SO42−+H2O (e) O2−+H2O⟶2OH−O2−+H2O⟶2OH− (f) [Cu(H2O)3(OH)]++[Al(H2O)6]3+⟶[Cu(H2O)4]2++[Al(H2O)5(OH)]2+[Cu(H2O)3(OH)]++[Al(H2O)6]3+⟶[Cu(H2O)4]2++[Al(H2O)5(OH)]2+ (g) H2S+NH2−⟶HS−+NH3

9 . The labels are Brønsted-Lowry acid = BA; its conjugate base = CB; Brønsted-Lowry base = BB; its conjugate acid = CA. (a) HNO3(BA), H2O(BB), H3O+(CA), NO3−(CB);NO3−(CB); (b) CN−(BB), H2O(BA), HCN(CA), OH−(CB); (c) H2SO4(BA), Cl−(BB), HCl(CA), HSO4−(CB);HSO4−(CB); (d) HSO4−(BA),HSO4−(BA), OH−(BB), SO42−SO42−(CB), H2O(CA); (e) O2−(BB), H2O(BA) OH−(CB and CA); (f) [Cu(H2O)3(OH)]+(BB), [Al(H2O)6]3+(BA), [Cu(H2O)4]2+(CA), [Al(H2O)5(OH)]2+(CB); (g) H2S(BA), NH2−(BB),NH2−(BB), HS−(CB), NH3(CA)

Which value for pOH corresponds to an acidic solution at room temperature? 3.7 5.9 9.2 7

9.2

Acidic, Neutral, and Basic (Hydronium ion vs Hydroxide ion concentration and pH)

Acidic = Greater hydronium, pH<7 Basic = Greater hydroxide, pH>7 Neutral = Equal amounts, pH = 7

Acid vs Base colors on solution

Acids - Pink; Bases - Blue

Which of the following is the term for a species that may either gain or lose a proton under appropriate conditions? Amphiprotic substance Brønsted-Lowry base Conjugate Brønsted-Lowry acid

Amphiprotic substance

If H2PO−4 behaves as an acid in water, what will result? HPO2−4 and OH− HPO2−4 and H3O+ PO3−4 and OH− PO3−4 and H3O+

B

If HSO−3 behaves as a base in water, what will result? SO2−3 and OH− SO2−3 and H3O+ H2SO3 and OH− H2SO3 and H3O+

C

BR Acid and BR Base

H.) A compound that donates a proton to another compound is called a Brønsted-Lowry acid, and a compound that accepts a proton is called a Brønsted-Lowry base. An

Consider the reaction below. According to the Bronsted-Lowry definition, which compound acts as the base in the forward direction? PH+4+H2O↽−−⇀PH3+H3O+

H2O

Of the following, which is not amphiprotic? HCO−3 H2SO4 H2PO−4 HS−

H2SO4

What is the conjugate acid of HSO−4?

H2SO4

Which of the following reactions shows water acting as the conjugate base of an acid? H2O+CO2↽−−⇀H2CO3 H2S+OH−↽−−⇀H2O+HS− H3O++HPO2−4↽−−⇀H2PO−4+H2O CN−+H2O↽−−⇀OH−+HCN

H3O++HPO2−4↽−−⇀H2PO−4+H2O

Calculate the H+ or OH- and state whether the solution is neutral, acidic, or basic. 1. 8.60 M H3O 2. 2.35*10^-9 M OH-

H>OH. Acidic. (Both).

Other amphoteric species

HCO3-

Strongest Acids

HCl, HBr, HI, HNO3, H2SO4, HClO4

If H2PO−4 behaves as a base in water, what will result? HPO2−4 and OH− HPO2−4 and H3O+ H3PO4 and OH− H3PO4 and H3O+

HPO2−4 and OH−

If H2PO−4 participates in an acid ionization, it will generate

HPO2−4.

. Explain why a sample of pure water at 40 °C is neutral even though [H3O+] = 1.7 ×× 10−7 M. Kw is 2.9 ×× 10−14 at 40 °C.

In a neutral solution [H3O+] = [OH−]. At 40 °C, [H3O+] = [OH−] = (2.910 × 10−14)1/2 = 1.7 ×× 10−7.

Amphiprotic

Species capable of either donating or accepting protons are called amphiprotic

Strong acid vs weak acid disassociation

Strong = completely Weak = Equilibrium

Which of the following statements about strong acids are true? The conjugate base of a strong acid has negligible acid-base properties. All strong acids have the same strength. They produce stable ions that have little tendency to accept a proton. They raise the pH of a solution by increasing the concentration of hydronium.

The conjugate base of a strong acid has negligible acid-base properties. They produce stable ions that have little tendency to accept a proton.

Autoionization

The process in which like molecules react to yield ions is called autoionization

Acid Ionization vs Base Ionization

The reaction between a Brønsted-Lowry acid and water is called acid ionization. Base ionization is with a base.

What is the hydronium ion concentration in an aqueous solution with a hydroxide ion concentration of 0.001 M at 25 °C?

[H3O+] = 1 ×10^-11M

A solution that has a greater hydronium concentration than hydroxide concentration will be: acidic basic neutral depends on the solution

acidic