Chemistry Chapters 3-4

Question 1

What is required for electrical conductivity?

Answer 1

The presence of ions in solution.

Question 2

What are cations?

Answer 2

Metal ions

Question 3

What are anions?

Answer 3

Non-metal ions

Question 4

What are salts?

Answer 4

Ionic compounds

Question 5

What are molecular compounds?

Answer 5

Compounds made up of non-metal atoms and do not form ions, therefore do not conduct electricity

Question 6

True or false: some molecular compounds can form ions

Answer 6

true

Question 7

What is a molecular solution?

Answer 7

Consists of one or more polar covalent compound that will mix with water (ex: ethanol in water, no dissociation)

Question 8

What is an ionic solution?

Answer 8

Consists of one or more ionic compounds dissolved in water (ex: NaCl dissolved in water, dissociation occurs and conducts electricity)

Question 9

What happens when an ionic compound dissolves in water?

Answer 9

The water molecules attract and separate the anions and cations in the solute.

Question 10

What is dissociation?

Answer 10

The process of separating positive and negative ions in solution. (dissociation equations)

Question 11

True or False: all ionic solutions dissolve at the same rate

Answer 11

false

Question 12

What is the concentration of ions when a solute is dissolving in water?

Answer 12

proportional to the concentration of solution formed (according to coefficients)

Question 13

How do you make a solution?

Answer 13

Dissolve some solute in solvent

Question 14

What is a saturated solution?

Answer 14

When no more solid will dissolve (there must be undissolved solid present)

Question 15

What happens when a precipitate is formed in a saturated solution?

Answer 15

The solution is saturated with the ions that form the precipitate.

Question 16

What is solubility?

Answer 16

The amount of solute required to make a certain volume of saturated solution (the max amount that can be dissolved in a particular volume of solution)

Question 17

True or false: Acids are soluble

Answer 17

True

Question 18

When do salts usually have low solubility?

Answer 18

when they contain phosphates, sulphites, and carbonates

Question 19

Give an example of a balanced equation

Answer 19

2KI(aq) + Pb(NO3)2 single arrow 2KNO3 (aq) + PbI2(s)

Question 20

Give an example of a complete ionic equation

Answer 20

2K+ 2I-… (include phases, do not split up the precipitate but still include it)

Question 21

Give an example of a net ionic equation

Answer 21

Pb2+(aq) + 2I-(aq) single arrow PbI2(s) (only the ions involved in the reaction, others are called spectators)

Question 22

What is hard water caused by?

Answer 22

the pressure of metal ions such as Ca2+ and Mg2+, the ions react with soap and inhibit their function

Question 23

What type of water is most likely to be hard?

Answer 23

slow-moving ground water has more time for the ions to dissolve

Question 24

How can you soften water

Answer 24

Add washing soda (NaCO3) to precipitate the metal ions

Question 25

Where does equilibrium exist in solutions, describe them

Answer 25

Between the undissolved solid and dissolved ions -dissolved compound always on the left and is solid, ions on the right side and aqueous -double arrows

Question 26

Where is equilibrium established in a saturated solution?

Answer 26

Between the dissolving and recrystallization of a salt

Question 27

What does Ksp stand for?

Answer 27

Solubility product constant

Question 28

What does the Ksp value represent?

Answer 28

High Ksp usually means high solubility, vice versa

Question 29

What happens to the concentration of ions and Ksp if the solubility of the substance increases?

Answer 29

they both increase

Question 30

True or false: ionic compounds with low solubility will not have Ksp values

Answer 30

false

Question 31

With trial Ksp in mind, when will a precipitate form?

Answer 31

when trial Ksp > Ksp

Question 32

What are operational definitions, give an example

Answer 32

Described physically what acids and bases do Ex: bases turn red litmus paper blue, acids react with magnesium

Question 33

What are conceptual definitions, give an example

Answer 33

Define acids or bases in terms of their molecular structure ex: acids contain H+, bases have OH-

Question 34

Give the Arrhenius definition of an acid

Answer 34

A substance that produces H+ in solution

Question 35

Give the Arrhenius definition of a base

Answer 35

A substance that produces OH- in solution

Question 36

What will happen when you place an acid with a strong base (an alkali metal with an OH-)?

Answer 36

The base will reduce all protons, acid + base = water + salt

Question 37

List some characteristics of acids

Answer 37

-sour taste -react with metals to produce H2 -conduct electricity

Question 38

List some characteristics of bases

Answer 38

-bitter taste -feel slippery/soapy -conduct electricity

Question 39

Give the Bronsted Lowry definition of an acid

Answer 39

Any substance that can dissociate or donate a hydrogen ion (H+ or protein) eg: HCl = H+ + Cl-

Question 40

Give the Bronsted Lowry definition of a base

Answer 40

Any substance that can accept a proton eg: OH- + H+ = H2O

Question 41

What is an amphiprotic substance?

Answer 41

A substance that can act as either an acid or a base depending on the situation (not at the same time) ex: H2O

Question 42

What are conjugate acid/base pairs

Answer 42

2 substances that only differ by one proton eg: NH3 and NH4+ a bronsted lowry acid base reaction always has 2 conjugate acid/base pairs

Question 43

What is a polyprotic substance?

Answer 43

An acid or base capable of donating or excepting more than one proton ex: H3PO4

Question 44

What is a strong acid?

Answer 44

-A substance that completely ionizes in an aqueous solution ex: HCl -dissociate completely in solution -single arrows

Question 45

What is a weak acid?

Answer 45

A substance that only partially ionizes in an aqueous solution -they reach equilibrium and do not dissociate completely -double arrows

Question 46

True or false: concentrated weak acids become strong acids

Answer 46

false, concentration has nothing to do with strong or weak acids

Question 47

What is a strong base?

Answer 47

a substance that completely dissociates in aqueous solutions ex: oxides (NaOH, KOH)

Question 48

What is a weak base?

Answer 48

a substance that produces few ions in solution ex: (nitrogen) NH3

Question 49

What is Ka and Kb?

Answer 49

Acid ionization constant and base ionization constant

Question 50

What does a large Ka or Kb indicate?

Answer 50

The acid or base is strong

Question 51

How can you see if the forward or reverse reaction is favoured from an acid base equilibrium?

Answer 51

comparing the Ka values of the 2 acids, the higher Ka value is the favoured direction (exception: if an acid has no charge, its direction will be favoured)

Question 52

Is pure water acidic or basic?

Answer 52

Neither, it is neutral!

Question 53

What is Kw?

Answer 53

[H3O+][OH-]

Question 54

What is autoionization?

Answer 54

When one water molecule donates a proton to another water molecule in a bronsted lowry equilibrium

Question 55

What 2 factors must be considered when reacting strong acids with strong bases?

Answer 55

1. Solutions will dilute each other (V1M1 = V2M2) 2. Acids and bases will neutralize each other (the resulting solution will be acidic or basic depending on what is left over)

Question 56

What is the formula for ph?

Answer 56

-log(H3O+) the amount of sig figs in the concentration will be the amount of decimal places

Question 57

How to get (H3O+) from ph?

Answer 57

10^-ph the amount of decimal places will be the number of sig figs

Question 58

True or false: there are different formulas for pOH and (OH-)

Answer 58

false, the formulas and rounding are the same