chem test Flashcards
1
Q
what is an element
A
pure substance that cannot be broken down
one type of atom
2
Q
what is a compound
A
pure substance with 2+ different atoms
can be broken down chemically
3
Q
physical vs chemical property
A
chemical is determined after undergoing a chemical reaction/ forming a new substance
4
Q
physical vs chemical change
A
physical is state or form, chemical is rearrangement of atoms and new substance
5
Q
some properties of metals
A
lustrous or dull good conductors solids at room temp malleable and ductile high melting and boiling
6
Q
some properties of non metals
A
low or no luster suck at conducting solids or gases brittle solids low to moderate melting and boiling
7
Q
properties of metalloids
A
lustrous or dull some are semiconductors solids brittle sometimes moderate melting and boiling
8
Q
how do transition metals form ions
A
with multiple charges
9
Q
smallest unit of an element
A
atom
10
Q
lose two electrons, what is the charge
A
+2
11
Q
an atom is electrically neutral if
A
of electrons = # of protons
12
Q
metals lose electrons to form:
A
cations
13
Q
non metals gain electrons to become:
A
anions
14
Q
atomic number represents the number of:
A
protons (and electrons if neutral)
15
Q
atomic mass:
A
protons and neutrons together
16
Q
atomic symbol of chlorine:
A
Cl
17
Q
iupac name for Au 3+
A
gold (iii)
18
Q
iupac name for calcium ion
A
literally just calcium lol
suck it
19
Q
prefix for seven
A
hepta
20
Q
bohr model of the atom, planetary model. list ways it contributed.
A
- electron orbits around nucleus
- each orbit of electrons corresponds to energy levels
- the farther the electron is from the nucleus, the greater it’s energy
- electrons don’t lose energy travelling in energy levels
21
Q
lewis symbols are convenient bc
A
they simply have the chemical symbol and a dot for each VALENCE electron
22
Q
noble gases are fancy bc they’re:
A
stable. don’t need to lose or gain electrons
23
Q
iso-electronic:
A
different atoms w the same number of electrons
24
Q
bohr rutherford diagrams
A
Be 2e 2e
25
Isotope:
same element, different number of neutrons.
26
isotopes have the same number of protons but different masses bc:
atomic mass is determined by protons and neutrons, and isotopes have diff numbers of neutrons
27
atomic number vs atomic mass
number of protons vs number of protons and neutrons
28
ionic compound vs molecular compound
molecular shares electrons, ionic lends them
molecular: NON metals
ionic: metal + non metal
29
ionic bond:
electrostatic force from transferring electrons
30
some properties of ionic compounds
```
hard brittle solids
crystal lattice structure
DO NOT EXIST AS NEUTRAL MOLECULES
strong ionic bonds=high melting points
soluble in water
conduct electricity
```
31
electrolytes:
substances that conduct electricity when dissolved in water
32
molecular compounds are formed by the joining of
neutral atoms (to form a molecule)
33
bonding pair:
a pair of electrons holding two atoms together
34
lone pair:
electrons not involved in a bond
35
single, single, triple covalent bond
one, two, three shared pairs
36
steps for drawing lewis structures of molecular compounds
1. count valence electrons for all atoms
2. central atom will need most electrons
3. place bond between central atom and each surrounding atoms to connect them
4. lone pairs around all surrounding atoms (not H)
5. (optional): if central atom doesn’t have full octet or electrons are remaining, add them as line pairs around central atom
37
electronegativity
tendency of an atom to attract a shared pair of electrons
38
electrons are shared equally (electronegativity):
non polar covalent bond
| electronegativity difference is less than 0.4
39
electrons are shared unequally (electronegativity):
polar covalent bond
| electronegativity difference is 0.4 or higher, less than 1.7
40
in ionic bonding, electrons are transferred. if the electronegativity diff between two atoms is ___ or higher, the bond is ___
1.7, ionic
41
some properties of molecular compounds
```
solids liquids or gases
composed of neutral atoms
melting and boiling low to moderate
some are soluble in water
don’t conduct electricity
NON electrolytes
```
42
prefix for 3
tri
43
when do you put prefixes?
molecular binary compounds only
44
prefix for nine
nono
45
prefix for 4
tetra
46
if compound has H before, it is an
acid
| HCl = hydrochloride acid
47
tertiary acids: change ite to ___ and ___ to ic.
ous, ate
48
law of conservation of mass
matter is not created or destroyed
mass of reactants = mass of products
49
chemicals do NOT destroy or change ___ into other ___
atoms into other atoms
50
balanced version of
| H2 (g) + O2 (g) = H2O
2H2 (g) + O2 (g) = 2H2O (l)
51
what state is a solution or acid
aq
52
synthesis reaction
two reactants, ONE new compound
53
decomposition reaction
compound breaks into two or more elements/compounds
54
reaction with oxygen: complete combustion
hydrocarbons + crapload of oxygen = ONLY carbon dioxide and water.
55
reaction with oxygen: incomplete combustion
hydrocarbons + smaller crapload of oxygen = 1+ of the following: CO2, CO, soot
56
when reacting with oxygen, what is always a product (to account for hydrogen)
water
57
reaction with oxygen: metals
form metal oxides or peroxides
58
reaction with oxygen: nonmetal
nonmetal oxides
59
reaction with oxygen: nonmetal oxides
produce other nonmetal oxides
60
single displacement:
ELEMENT + COMPOUND = new element + new compound
61
corrosion:
breakdown of metal resulting from reactions
62
metals that don’t corrode
gold, platinum
63
double displacement
two compounds = two new compounds
64
double displacement: precipitation
two new compounds, one being precipitate.
precipitate= insoluble in solubility table
65
double displacement: acid base neutralization
acid + base = water and a salt
| if base is carbonate, CO2 is also produced
66
mole:
unit of measurement
mole of one substance is atomic mass
67
avodragos number
6.02 x 10 to the 23rd
68
molar mass
mass of one mile of any substance in g/mol
69
n = what
number of mol
70
M =
molar mass
71
m =
mass of sample
72
N =
number of entities (u/molecules/atoms)
73
NA =
6.02 x 10 to the 23rd entities/mol
74
n = m/?
n = m/M
75
n = ?/NA
n = N/NA
76
m/? = N/NA
m/M = N/NA
77
formula for stoich
given amount, convert to moles, molar mass, convert to desired units
78
ALWAYS BALANCE THE
EQUATION
79
AFTER ELEMENTS/COMPOUNDS, ADD
STATES
80
the ostwald process:
used for making nitric acid
important for the time
fundamental change in agriculture
81
properties of acids
```
corrosive
sour tasting
release hydrogen ions when dissolved
pH is LESS THAN SEVEN
electrolytes
```
82
properties of bases
```
corrosive
bitter tasting
release hydroxide ions when dissolved
pH GREATER THAN SEVEN
electrolytes
```
83
ionization:
molecular compounds dissolve to produce ions
84
dissociation:
ionic compounds dissolve to produce ions
85
Arrhenius’s theory of acids and bases:
acids are substances that dissociate in water to yield ions
86
pH:
measure of the concentratipn of hydrogen ions
87
pH scale:
measures the level of acidity and basidity
88
pH scale goes from 0-14. 14 is lowest ___ and highest ___
lowest acidity, highest basidity
89
from pH level 7 to 6, it gets ___ more acidic.
10x
90
pH level 0 (battery acid) formula
H > OH
91
pH level 7 (fresh water) formula
H = OH
92
pH level 14 (drain cleaner) formula
H < OH
93
pH of 11 is
moderately basic
94
pH of 2 is
very acidic
95
strong ACIDS ___ completely
ionize
96
weak ACIDS ___ partially
ionize
97
strong BASES ___ completely
dissociate
98
weak BASES partially react with
water
99
strong and weak acids and bases of similar concentration have ___ properties
different
100
acid base indicators (red cabbage) are chemicals that
change colour when reacting with bases or acids
101
acid base indicators change ___ with different pH levels
colour
102
nonmetal oxides react with water to form
acids
103
metal oxides react with water to form
bases
104
phosphoric acid is used in
soft drinks
105
windex is
ammonium hydroxide
106
how to determine the pH of a solution
acidic: H > 1 x 10 to the -7
basic: H < 1 x 10 to the -7
107
if you are given the H+ in mol/L, what formula
pH = -log(1x10 to the -6)
108
what is the pH of a solution with a H+ of 4.7 x 10 to the -11 mol/L
10.3
109
how to convert pH to H+
inverse log of the - pH
H = 10 to the -9 = 1 x 10 to the -9 mol/ L
110
what is the H+ of a solution with a pH of 2.8
1.6 x 10 to the -13 mol/L
111
how can the pH of a solution be changed
adding acid, base, or water
112
pH of normal rainwater, 0.0000026 mol/L
5.6
113
hydrogen concentration of drain cleaner, pH of 14
1 x 10 to the -14 mol/L
114
titration:
lab to find unknown concentration
115
CA VA = CB VB
c = n/v
NA = NB
titration formula
116
random example of acid base neutralization
baking: baking powder contains tartaric acid and sodium bicarbonate
bubbles of CO2 allow cake to rise as it bakes
117
acid precipitation
any form of precipitation that becomes acidic from reaction the compounds in the atmosphere
118
titration
process where a solution of known strength is added to a certain volume of a treated sample containing an indicator.
119
can two atoms be isotopes if they have different atomic numbers but same atomic masses?
no. their masses can be different but their atomic numbers must be the same.
120
if a lewis structure is of an ion, you must include the ion change of the
electrons
121
determine the bond type for O-O
electronegativity difference: 3.5 - 3.5 = 0
non polar bond
122
what is the bond type for S-Cl
electronegativity difference: 3-2.5=0.5
| polar
123
bond type of Na-O
electronegativity difference: 3.5 - 0.9 = 2.6
124
differences between ionic and molecular compounds: PROPERTIES
ionic: high melting point, conduct electricity
molecular: low to moderate melting point, nonelectrical conductors
125
differences between ionic and molecular compounds: ELECTRONS
ionic: TRANSFER of electrons (metals to non metals)
molecular: electrons SHARED between nonmetals
126
what’s the difference between a strong and weak acid
strong acids ionize almost completely so there is a greater concentration of H+ ions, lower pH, and are more corrosive.
127
neutral solutions have a pH of
7
128
a solution with a pH of 4 has. a greater H+ than __
OH.
129
the diatomic elements
HOFBrINCl
130
what does HOFBrINCl stand for
```
diatomic elements
hydrogen
oxygen
fluoride
bromine
iodine
nitrogen
chlorine
```
131
how many reactions in the ostwald process
three
132
rate of reaction
time it takes for a given amount of product/reactants to react or form
