CHAPTER 4 Flashcards
(113 cards)
1
Q
A homogeneous mixture of two or more substances and components are mixed uniformly together.
A
solution
2
Q
A substance that is present in a smaller amount.
A
solute
3
Q
The substance is present in a larger amount and may be a solid, liquid, or gas.
A
solvent
4
Q
The solute initially is a liquid or a solid and the solvent is water.
A
aqueous solution
5
Q
A substance that, when dissolved in water, results in a solution that can conduct electricity.
A
electrolytes
6
Q
A substance that does not conduct electricity when dissolved in water.
A
non-electrolytes
7
Q
What allows the solutions to conduct electricity?
A
The movements of ions.
8
Q
Breaking up of the compound into cations and anions.
A
dissociation
9
Q
They have large dipole moments (“partial charges”) and contain bonds between atoms with very different electronegativities such as oxygen and hydrogen.
A
polar solvent
10
Q
The process in which an ion is surrounded by water molecules.
This also helps to stabilize ions in solution and prevents cations from recombining with anions.
the result of a strong interaction between solute particles and H2O molecules.
A
hydration
11
Q
The separation of acids and bases into ions.
A
ionization
12
Q
The reaction can occur in both directions.
A
reversible reaction
13
Q
Most ____ substances, aside from acids and bases, are nonelectrolytes and do not conduct electricity in aqueous solutions.
A
molecular substances
14
Q
Why does an aqueous solution of an ionic substance conduct an electric current?
A
The solution contains ions that are free to move.
15
Q
What structural feature will allow a substance to conduct an electric current?
A
The presence of charged particles that are free to move independently.
16
Q
Dissociates or ionizes 100% in water and conducts an electric current in aqueous solution.
A
strong electrolyte
17
Q
Dissociates or ionizes less than 100% in water, and conducts a limited amount of electric current in aqueous solution.
A
weak electrolyte
18
Q
Does not dissociate or ionize in water and does not conduct an electric current in aqueous solution.
A
nonelectrolyte
19
Q
What ions are released when the ionic compound Fe2(SO4)3 dissociates in aqueous solution?
A
SO42–
Fe3+
20
Q
When an ionic compound dissolved in water, the cations are attracted to the ___ atom(s) of the H2O molecule, while the anions are attracted to the ___ atom(s).
A
oxygen; hydrogen
21
Q
In aqueous solution, a soluble ionic compound dissociates into its ___, which are free to move independently, allowing the solution to conduct electricity. Ionic compounds are therefore classified as ___.
A
ions; electrolytes
22
Q
An electric current is a flow of charge through a medium, and can be carried by the movement of ___.
A
electrons and ions
23
Q
___ will not ionize or dissociate in water and is therefore a nonelectrolyte.
A
Glucose (C6H12O6)
24
Q
___ will ionize in the presence of water to a small extent (< 100%) and is therefore a weak electrolyte.
A
Ammonia (NH3)
25
Which of the following balanced equations correctly represents the dissociation of Ni(NO3)2 in water?
Ni(NO3)2(s) → Ni2+(aq) + 2NO3–(aq)
Ni(NO3)2 consists of Ni2+ ions and NO3– ions, which dissociate from each other in aqueous solution. Each unit of Ni(NO3)2 forms one Ni2+ ions and two NO3– ions.
26
Why is an acid able to produce ions in aqueous solution?
An acid (H-X) dissociates into H+ and X- in solution. Each ion is surrounded by water and stabilized by hydration.
27
Strong acids and bases ___ completely to form ___ in water. The resulting solution conducts electricity well; hence these compounds are classified as ___ electrolytes.
ionize: gas: strong
28
Acids (e.g. HCl) are ___ compounds that nonetheless produce ions in aqueous solutions as the H2O molecules attract the ionizable hydrogen atoms in the compound, causing the ___ H-X bond to break. Acids are therefore electrolytes.
ionic; covalent
29
The formation of an insoluble product, known as a precipitate.
One common type of reaction that occurs in aqueous solution.
____ reactions usually involve ionic compounds.
A ___ reaction is a reaction in which two or more water-soluble ionic compounds react in aqueous solution to form one or more insoluble/solid precipitates.
precipitation reaction
30
An insoluble solid that separates from the solution.
precipitate
31
A reaction that involves the exchange of parts between the two compounds.
Also called as a double-displacement reaction.
metathesis reaction
32
The maximum amount of solute that will dissolve in a given quantity of solvent at a specific temperature.
solubility
33
A substance is ____ if a fair amount of it visibly dissolves when added to water.
soluble
34
All ___ compounds are strong electrolytes, but they are not equally soluble.
ionic
35
The formulas of the compounds are written as though all species existed as molecules or whole units.
It identifies the reagents; however, it does not describe in detail what actually is happening in solution.
molecular equation
36
Dissolved species are free, hydrated ions.
Charges and atoms must be balanced in an ___equation.
Charges must be included where relevant in an ___equation.
The ___equation includes all ions, including spectator ions.
ionic equation
37
Ions that are not involved in the overall reaction.
They appear on both sides of an equation, they can be eliminated from the ionic equation.
Ions that do not participate in the reaction although they are present
spectator ions
38
Shows only the species that actually take part in the reaction.
net ionic equation
39
PROCEDURE FOR WRITING IONIC AND NET IONIC EQUATIONS
1. balance molecular equation
2. write ionic equation
3. cancel spectator ions
4. net ionic equation
40
Which of the following options correctly contrast strong and weak acids in terms of electrolyte behavior?
Both strong and weak acids are electrolytes.
A solution of a weak acid always contains some unionized acid molecules.
All molecules of a strong acid will ionize in aqueous solution.
41
Match each type of hydrogen atom in the formula CH3COOH.
H of CH3 group -> NOT readily ionizable
H of COOH group -> READILY ionizable
42
What ions are released when the ionic compound Fe2(SO4)3 dissociates in aqueous solution?
SO42–
Fe3+
The cation in this compound is Fe3+. You can determine this from SO42-- present. If there are 3 SO42– ions, the total negative charge is 3(–2) = –6. The total positive charge must therefore be +6, meaning that each Fe ion must carry a 3+ charge.
43
The symbol ⇌ indicates that a reaction is ___, meaning that reactants are converted to products and products are in turn reconverted to reactants.
An acid undergoes partial ionization in water.
An aqueous solution contains a weak electrolyte.
reversible
44
Ionize completely in aqueous solution
strong acids
45
Strong acids are classified as ___
strong electrolytes
46
They form very few ions in aqueous solution
weak acids
47
Weak acids are classified as ___
weak electrolytes
48
Why is the formula for acetic acid typically written as CH3COOH instead of C2H4O2?
The H of the COOH group is ionizable, while the H atoms bonded in the CH3 group are not.
49
When a chemical reaction is reversible _____.
reactants and products are present together
products react to form reactants
reactants continuously form products
50
When a reversible chemical reaction occurs in a closed system, a state of dynamic chemical equilibrium is reached when the ____ of the forward and reverse reactions are equal. At this point the ____ of the reactants and products no longer change, although the forward and reverse reactions continue to occur.
rates; concentrations
51
There appears to be no visible change in the concentrations of reactants or products.
The forward and reverse reactions occur at equal rates.
chemical system at equilibrium
52
Readily reversible and reaches chemical equilibrium under ordinary conditions
The ionization of CH3COOH in aqueous solution
53
Ions that always form soluble ionic compounds
NO3–
Group 1A cations
NH4+
54
The balanced equation below is not a representation of metathesis reaction.
Pb(NO3)2(aq) + 2NaCH3COO(aq) → Pb(CH3COO)2(aq) + 2NaNO3(aq)
This reaction is NOT a metathesis reaction. A metathesis reaction is one in which two compounds exchange partners. Although it appears that this happens in the equation shown here, because both products are soluble in water all the ions simply remain dissociated and separate in solution. No actual exchange of partners has occurred.
55
A reversible reaction in a closed system can reach a state of chemical ___, in which the rate of the forward reaction is equal to the rate of the reverse reaction.
equilibrium
56
These compounds are ___ in water
NH4Cl
Pb(NO3)2
Na3PO4
(NH4)2CO3
Ca(ClO3)2
K2SO4
soluble
57
What are the influences in the solubility of a solute in a solvent?
Quantity of solvent
Chemical nature of the solute
Temperature
58
The following cations often produce water- ___ salts, even with anions such as SO4 2-
Ag+
Hg2 2+
Pb2+
insoluble
59
A chemical equation that shows all reactants and products as intact, undissociated compounds is called a(n)
____. The name is misleading because not all compounds are composed of ____.
molecular
| molecules
60
An ionic equation shows species ____ in solution. This equation is the ____ accurate representation of the chemical change occurring.
An ionic equation shows ALL species present, not just spectator ions. This gives the most accurate representation of the chemical reaction occurring.
61
Ions that typically form water-___salts, except when partnered with a Group 1A cation or NH4+
OH–
PO43–
CO32–
insoluble
62
new ion combination that may form a precipitate
cation-anion
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will not form a precipitate
soluble ion combination
64
cannot combine to form a compound
cation-cation
65
will precipitate from solution
insoluble ion combination
66
compounds that are correctly paired with their solubility in water at 25°C.
CaSO4, ___
(NH4)2S, ___
insoluble; soluble
67
A ___equation will not include any charges on any of the species.
This equation represents all reactants and products as if they were intact and undissociated.
molecular equation
68
It is the ___ in solution that will combine to form a precipitate in this type of reaction, not molecules. A precipitate is an ___ salt.
ions; insoluble
69
Substances that ionize in water to produce H+ ions.
have a sour taste
cause color changes in plant dyes; for example, they change the color of litmus from blue to red.
They react with certain metals such as zinc, magnesium and iron to produce hydrogen gas.
They react with carbonates and bicarbonates such as Na2CO3, CaCO3, and NaHCO3, to produce carbon dioxide gas.
acids
70
____ acid solutions conduct electricity
aqueous
71
Substances that ionize in water to produce OH- ions.
Have a bitter taste
slippery
cause color changes in plant dyes; for example, they change the color of litmus from red to blue.
example of this:
Ba(OH)2
NH3
NaOH
bases
72
____ base solutions conduct electricity.
aqueous
73
Swedish chemist who defined acids and bases to classify substances whose properties in aqueous solutions were well known.
Svante Arrhenius
74
Acid increases the concentration of H+ ions in aqueous solution
Acid according to Arrhenius
75
Base increases the concentration of OH- ions in aqueous solution
Base according to Arrhenius
76
Danish chemist
Johannes Bronsted
77
proton donor
Acid according to Bronsted-Lowry
78
proton acceptor
Base according to Bronsted-Lowry
79
Each unit of the acid yield one hydrogen ion upon ionization.
monoprotic acids
80
ionizes completely in aqueous solution
strong acid
81
has a low percentage ionization in aqueous solution
weak acid
82
there are no intact molecules
in a solution of a strong acid
83
there will be intact acid molecules as well as ions
in a solution of a weak acid
84
The following substances are ____:
H2O
HSO4–
HCO3–
amphoteric
85
The following substances are ____:
HBr(aq)
H3PO4(aq)
CH3CH2COOH(aq)
acidic
86
neutralization occurs between _____ and _____.
their products are typically ionic compound which is called salt and the neutral molecule water
The net ionic equation is typically given by H+ (aq) + OH–(aq) → H2O(l).
strong acid and strong base
87
The reaction between an acid and a base is often called a(n) ____ reaction because the H+ ions produced by the acid react with OH– ions produced by the base, thus ____ each other.
neutralization; neutralizing
88
The following are considered ___ in the aqueous solution:
Ca(OH)2
NaOH
NH3
Na2O
basic
89
transfer of electrons from one atom or ion to another
electrons
90
The transfer of electrons in a redox reaction is tracked using a(n) ___ number. This number is the charge an atom would have if all bonds were ___ in nature.
oxidation; ionic
91
the species being reduced in oxidation
the species that shows a decrease in oxidation number
gains electrons
oxidizing agent
92
the species oxidized in oxidation
the species that shows an increase in oxidation number
loses electrons
reducing agent
93
half-reaction that involves loss of electrons
oxidation reaction
94
half-reaction that involves gain of electrons
In a decomposition reaction a single reactant forms two or more different products.
A thermal decomposition involves heat and is indicated using the symbol Δ.
In a displacement reaction the number of substances on both sides of the equation remains the same.
reduction reaction
95
signifies the number of charges the atom would have in a molecule (or an ionic compound) if electrons were transferred completely
track movement of electrons in chemical reactions
the charge of an atom WOULD have if electrons were always transferred, but it is NOT an actual charge.
oxidation number or oxidation state
96
Rules for assigning oxidation numbers
(1) The sum of the oxidation numbers for the atoms in a neutral compound is zero
(2) The oxidation number for a monatomic ion is the same as its charge
97
the highest oxidation number any main-group element from period 3 onward can have is equal to ____
the A-group number
98
Displacement reactions are a type of oxidation-reduction reaction.
Displacement reactions involve an ion (or atom) in a compound that is replaced by an ion (or atom) of another element.
Displacement reactions
99
All elements can have an oxidation state of 0.
Metals tend to have positive oxidation numbers only.
Transition metals usually have more than one possible oxidation number.
periodic trends in oxidation number
100
the ___ of a substance results in an increase in its oxidation number and lose electrons.
oxidation
101
the ___ of a substance results in a decrease in its oxidation number and gain electrons
reduction
102
any metal listed in activity series will react with any ____ (in a compound) below it)
metal
103
All elements can have an oxidation state of 0.
Metals tend to have positive oxidation numbers only.
Transition metals usually have more than one possible oxidation number.
periodic trends in oxidation number
104
a convenient summary of the results of many possible displacement reactions
A metal higher up on the list will displace the ions of another metal further down the list from solution.
Metals become less reactive the further down the series you go.
Metals high on the list react more easily with cold water than metals low on the list.
activity series
105
any metal above ___ will displace it from water or from an acid, but metals below ____ will not react with either water or an acid
hydrogen
106
reaction in which two or more substances combine to form a single product
combination
107
the breakdown of a compound into two or more components
decomposition
108
a reaction in which a substance reacts with oxygen, usually with the release of heat and light to produce a flame
combustion
109
an ion (or atom) in a compound is replaced by an ion (or atom) of another element
fit into one of three subcategories: hydrogen ___, metal ___, or halogen ___
displacement
110
all alkali and some alkaline earth metals (Ca, Sr, and Ba), which most reactive of the metallic elements will displace hydrogen from cold water
hydrogen displacement
111
a metal in a compound can be displaced by another metal in the elemental state
metal displacement
112
another activity series summarizes the halogens' behavior
F2 > Cl2 > Br2 > I2
Halogen displacement
113
an element in one oxidation state is simultaneously oxidized and reduced
one reactant always contains an element that can have at least three oxidation states
disproportionation
