chapter 6: Types of chemical reactions Flashcards
1
Q
what is dissolution
A
When an ionic substance dissolves in water, the solvent pulls the individual ions from the crystal and solvates them
2
Q
What is another name for dissolution?
A
dissociation
3
Q
Why is an ionic salt soluble in water?
A
Because the interactions between ions and water are strong enough to overcome the lattice energy of the crystal
4
Q
What does (aq) stand for
A
Aqueous solution
5
Q
What does aqueous solution indicate
A
Hydration of the ions
6
Q
Example of aqueous solution
A
NaCl —> (H2O) Na+ (aq) + Cl (aq)
7
Q
What is a soluble compound
A
A substance that dissolves in water
8
Q
What is insoluble compound
A
It does not dissolve in water
9
Q
What do the differences in solubility of ionic compounds depend on
A
Attractions of the ions to one another and the attraction of the ions to the water molecules
10
Q
what is a solution
A
homogenous mixture of 2 or more substances
11
Q
what is a solvent
A
what does the dissolving
12
Q
what is an aqueous solvent
A
water is the solvent
13
Q
what is a solute
A
what is being dissolved
14
Q
what is an electrolyte
A
dissociates into ions when dissolved in water
15
Q
what is a nonelectrolyte
A
many dissolve in water but it does not dissociate
16
Q
what does a material need to conduct electricity
A
charged particles
17
Q
what is an electrolyte solution
A
all contain ions dissolved in water
18
Q
what is a nonelectrolyte solution
A
contain whole molecules dissolved in water
19
Q
what happens when strong electrolytes dissolve in water
A
dissociates completely
20
Q
what happens when weak electrolytes dissolve in water
A
only partially dissociates
21
Q
what types dissociate in water
A
strong electrolytes
22
Q
strong electrolytes =
A
strong acids
23
Q
what are strong acids
A
undergo ionization reactions to produce H+ ions and anions that are represented in balanced chemical equations
24
Q
what are the 7 common strong acids
A
- ) sulfuric (H2SO4)
- ) hydrochloric (HCL)
- ) Hydrobromic (HBr)
- ) Perchloric (HClO4)
- ) Chloric (HClO3)
- ) Hydroiodic acid (HI)
- ) Nitric Acid (HNO3)
25
strong acids and bases are
soluble
26
what is a soluble ionic compound
strong electrolytes
27
What is a balanced equation
equation for a chemical reaction in which the number of atoms for each element in the reaction and the total charge is the same for both the reactants and the products
28
what are weak acids
only partially dissociate, so they only
| produce a low concentration of ions in solution
29
what equilibrium arrow is used for weak acids and bases
the one where it goes in both directions to show that the reaction does not complete
30
what are weak bases
partially dissociate
31
what categories can electrolytes be in
ionic or molecular
32
what are some examples of ionic strong electrolytes
soluble salts and strong bases
33
what is an example of a ionic nonelectrolyte
insoluble salts
34
what is an example of a molecular strong electrolyte
strong acids
35
what is an example of a weak molecular electrolyte
weak acids and weak bases
36
what is an example of a molecular nonelectrolyte
all other compounds
37
what is concentration
designates the amount of solute
dissolved in a given quantity of solvent or quantity of
solution
38
what is molarity
one way to measure the concentration of
| a solution
39
what is the formula for Molarity (M)
moles of solute/ volume of solution in liters
40
what is the first step for making a concentrated solution
one weighs out a known
mass (which can be convert to
number of moles) of the solute
41
what is the 2nd step for making a concentrated solution
solute is added to a
volumetric flask, and solvent is
added to the line on the neck of
the flask
42
what is a stock solution
Solutions that are used routinely
in the lab are often prepared (or
purchased)
43
what is diluted
Solutions of lower concentrations
44
what happens if a dilute solution contains the same volume as a concentration solution
the relationship between the amount of solute and solvent must be different
45
how can someone dilute a concentrated solution
dilution
46
how does dilution work
use a pipet to deliver a specific amount of the concentrated solution to a new volumetric flask
- add solvent until the line on the neck of the flask is reached
47
what is the formula for dilution
molc=mold
| Mc x Vc = Md x Vd
48
what is a precipitation reaction
reactions that result in the formation of an insoluble product
49
what is a precipitate
The insoluble
| product
50
what is solubility
amount of that
substance that dissolves in a given quantity of
solvent at a given temperature
51
what are some soluble ionic compounds
Li+, Na+ K+, Cs+, Rb+, NH4+ (No exceptions)
52
what are some soluble ionic compounds
NO3-, C2H3O2- (none exceptions)
53
what are some soluble ionic compound
Cl-, Br-, I- (exceptions (Ag+, Hg2+2, Pb+2)
54
what are some soluble ionic compounds
SO4-2 ( Ca+2, Sr+2, Ba+2, Ag+2, Hg+2, Pb+2,
55
what are some insoluble ionic compoinds
S-2, OH-
56
what are some insoluble ionic compounds
CO3-2, CrO4-2, PO4-3
57
what is a molecular equation
shows the complete neutral
formulas and phases for each compound in the
aqueous reaction
58
what is a complete ionic equation
all strong
electrolytes (strong acids, strong bases, and
soluble ionic salts) are dissociated into their ions
59
what is another name for complete ionic equation
ionic equation
60
what does an ionic equation show
accurately reflects the species that are found in the reaction mixture
61
what is the net ionic equation
cross out anything
that does not change from the left side of the
equation to the right
62
what are spectator ions
those that didn't change (deleted from the net ionic equation)
63
what is the other type of stoichiometry problem
molarity-molarity
64
what are some characteristics of acids
have a sour taste.
−Can dissolve many metals
−Ability to neutralize bases
65
what does the Latin word acidus mean
sour or tart
66
what are some characteristics of bases
have a bitter taste
- feel slipper to the touch
- ability to neutralize acids
67
where does the word base come from
english word which means to bring low
68
who was svante arrhenius
(`1880)
| - swedish chemist
69
what was the arrhenius theory
acids are substances that increase the concentration of H+
| bases are substances that increase the concentration of OH- when dissolved in water
70
what are some problems with arrhenius theory
1.) does not explain why molecular substances like NH3 and Na2CO3, Na2O dissolve in water
(bc they do not contain OH-ions)
2.) does not explain why molecular substances like CO2 dissolve in water
(they do not contain H+ ions)
3.) it does not explain acid-base reactions that take place outside aqeuous solutions
71
who were bronsted and lowry and what did they do
(1923)
- Johannes Bronsted was a danish chemist
-Thomas lowry was an English Chemist
they proposed a general definition of acids and bases
72
what was the bronsted-lowry theory
acids are proton donors
(must have a removable proton)
bases are proton acceptors
(must have a pair of nonbonding electrons)
73
what is a neutralization reaction
a solution of an acid and a solution of a base
| are mixed
74
what does a neutralization reaction between acid and metal hydroxide produce
water and a salt
75
what is a salt
ionic compound whose cation comes from a base and the anion comes from an acid
76
what does cation mean
to lose an electron
77
what does anion mean
to gain electron
78
what is a titration
analytical technique in which one can
| calculate the concentration of a solute in a solution.
79
what is standard solution
solution of a known concentration
80
what does titration involve
combing sample of unknown w/ standard solution
81
what is the equivalence point
```
point at which the two
different solutions (known and unknown) are at
stoichiometrically equivalent quantities.
```
82
what is used in acid-base titrations
indicators or dyes
83
why is equivalence point never found
acid-base titrations dyes and instead the end point is found
84
what reaction does precipitation, acid base, gas evolution rections involve
oxidation-reduction reaction
85
what is an oxidation-reduction
Reactions that involve transferring electrons from one
| atom to another
86
what is oxidation
occurs when an
| atom or ion loses electrons
87
what is reduction
an
| atom or ion gains electrons.
88
when do redox reactions occur
in and out of solution
89
what is an example of redox reaction
rusting iron, bleaching hair, producing electricity
90
how can you determine if an oxidation-reduction reaction has occured
we assign an oxidation number
91
what can oxidation number help us with
determine the electron flow in the reaction
92
what are oxidations not
ion charges
93
what is the first rule of oxidation numbers
free elements = 0
| Na, Be, K, Pb
94
in monatomic ions the oxidation number is equal to what
the charge on the ion
Li+ = +1
Fe+3 = +3
95
Group IA metals have a charge of
+1
96
Group 2A have a charge of
+2
97
aluminum is always
+3
98
what oxidation number do nonmetals have
negative
99
what is the oxidation number of hydrogen
+1 but -1 when bonded to metals
100
what is the oxidation number of O
-2
101
what is exception for oxygen
H2O2 bc it is -1
102
what oxidation numbers do halogens
-1
103
what is the sum of the oxidation numbers in a neutral compound
0
| example:NaCl
104
what is the sum of the oxidation numbers on a polyatmic
The sum of the oxidation numbers in a polyatomic
| ion is the charge on the ion
105
when does oxidation occur
atoms oxidation increases during reaction
106
when does a reduction occur
atoms oxidation state decreases during reaction
107
oxidation and reduction must occur...
simultaneously
108
what is a reducing agent
reduces an element in another
reactant is called the reducing agent.
- contains the element that is oxidized
109
what is an oxidizing agent
The reactant that oxidizes an element in another
reactant
-contains the element is reduced
