Chapter 4 - Aqueous Solutions

Question 1

Solution is
2. Which is less?
3. Electrolyte Soluton and Nn-Elecrolyte Solutioin.

Answer 1

Solvent + Solute
Solute is less than Solvent.
3. Strong Electrolytes: Salts - Acids - Bases. Anything else is weak.

Question 2

What are electrolytes

Answer 2

Electrolytes are substances that dissociate into ions (cations and anions) when dissolved in water, allowing the solution to conduct electricity

Question 3

Difference between strong and weak electrolytes

Answer 3

Strong electrolytes fully dissociate into ions, while weak electrolytes only partially dissociate.

Question 4

Examples of strong acids

Answer 4

HCl, HBr, HI, HNO3, H2SO4, HClO3, HClO4

Question 5

Examples of weak acids

Answer 5

HF, HNO2, H2CO3, H2SO3, H3PO4, HClO, CH3COOH (acetic acid)

Question 6

Examples of strong bases

Answer 6

Alkali metal hydroxides (LiOH, NaOH, KOH), soluble earth alkali hydroxides (e.g., Ba(OH)2)

Question 7

Example of a weak base

Answer 7

Ammonia (NH3)

Question 8

Solubility rules for salts

Answer 8

All alkali metal, ammonium, nitrate, bicarbonate, chlorate, and perchlorate salts are soluble. Most halides and sulfates are soluble, with some exceptions (e.g., salts with Ag+, Pb2+, Hg22+).

Question 9

Net ionic reaction

Answer 9

A net ionic reaction shows only the chemical species that are involved in a reaction, excluding spectator ions

Question 10

Brønsted definition of acids and bases

Answer 10

An acid is a proton donor, and a base is a proton acceptor

Question 11

Monoprotic, diprotic, and triprotic acids

Answer 11

Monoprotic acids can donate 1 proton, diprotic acids can donate 2 protons, and triprotic acids can donate 3 protons

Question 12

Example of an acid-base reaction

Answer 12

HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)

Question 13

Net ionic reaction for acid-base reaction

Answer 13

H+(aq) + OH–(aq) → H2O(l)

Question 14

Brønsted acid example

Answer 14

HCl (hydrochloric acid)

Question 15

Brønsted base example

Answer 15

NH3 (ammonia)

Question 16

Amphiprotic species*

Answer 16

A species that can act as both a Brønsted acid and a Brønsted base (e.g., HCO3−, H2O)

Question 17

Precipitation reaction

Answer 17

A reaction in which two solutions of soluble compounds are mixed, and a new combination of ions produces an insoluble compound

Question 18

Insoluble compounds

Answer 18

Carbonates, phosphates, chromates, dichromates, sulfides, and hydroxides (with some exceptions, such as alkali metal salts and earth alkali hydroxides)

Question 19

Acid dissociation reaction example

Answer 19

HCl(aq) + H2O(l) → H3O+(aq) + Cl−(aq)

Question 20

Hydronium ion*

Answer 20

H3O+; formed when water accepts a proton from an acid.

Question 21

Dissociation steps for diprotic acids

Question 22

Dissociation steps for triprotic acids

Question 23

Example of an acid-base reaction with ammonia

Answer 23

NH3(aq) + HCl(aq) → NH4Cl(aq)

Question 24

Net ionic reaction for an acid-base reaction

Answer 24

H+(aq) + OH–(aq) → H2O(l)

Question 25

Solubility rule for alkali metal and ammonium salts

Answer 25

All alkali metal and ammonium salts are soluble, with no exceptions

Question 26

Solubility rule for nitrates, bicarbonates, chlorates, and perchlorates

Answer 26

All nitrates, bicarbonates, chlorates, and perchlorates are soluble, with no exceptions

Question 27

Solubility rule for halides

Answer 27

All halides (Cl−, Br−, I−) are soluble, with exceptions for salts with Ag+, Pb2+, and Hg22+

Question 28

Solubility rule for sulfates

Answer 28

All sulfates (SO42−) are soluble, with exceptions for salts with Ag+, Ca2+, Sr2+, Ba2+, Pb2+, and Hg22+.

Question 29

Example of a compound that can act as both a Brønsted acid and a Brønsted base

Answer 29

HCO3− (bicarbonate ion)

Question 30

What is oxidation?

Answer 30

Oxidation is the process of losing electrons

Question 31

What is reduction?

Answer 31

Reduction is the process of gaining electrons.

Question 32

What are oxidation numbers used for?

Answer 32

Oxidation numbers are used to keep track of electrons in redox reactions.

Question 33

What are the main types of redox reactions?

Answer 33

Combination, decomposition, combustion, displacement, and disproportionation reactions.

Question 34

What is molarity (M)?

Answer 34

Molarity is a measure of solution concentration expressed as moles of solute per liter of solution (mol/L).

Question 35

What is the dilution equation?

Answer 35

MiVi = MfVf, where Mi and Vi are the initial molarity and volume, and Mf and Vf are the final molarity and volume.

Question 36

What is the oxidation number of an element in a neutral compound?

Answer 36

The sum of oxidation numbers in a neutral compound equals zero

Question 37

What is the oxidation number of oxygen in most compounds?

Answer 37

The oxidation number of oxygen is usually -2, except in peroxides where it is -1.

Question 38

Rules for assigning oxidation numbers

Question 39

Oxidation numbers across the periodic table

Question 40

Types of redox reactions

Answer 40

Combination reactions: e.g. 4Fe + 3O2 → 2Fe2O3 where Fe is oxidized and O reduced Decomposition reactions: e.g. 2KClO3 → 2KCl + 3O2 where Cl is reduced (from +5 to −1) and O is oxidized (from −2 to 0) Combustion reactions: combustion is reaction with oxygen, e.g. CH4 + 2O2 → CO2 + 2 H2O Displacement reactions: a reaction where an atom or ion is displaced by another element, e.g.: Ca + 2H2O → Ca(OH)2 + H2 the Ca replaces the H in its combination with oxygen Mg + 2HCl → MgCl2 + H2 the Mg replaces the H in its combination with Cl− Cl2 + 2KBr → 2KCl + Br2 the Cl replaces the Br in its combination with K+ Disproportionation reactions: a reaction when the same element in part is oxidized and in part reduced, e.g.: H2O2 → H2O + O2 Etc.