chapter 3

Question 1

The 6 basic SI metric units

Answer 1

Meter (m) for length
Kilogram (Kg) for mass
second(s) for time
mole (mol) for amount of substance
Kelvin (K) for temp
Ampere (A) for electric current
*pg 34*

Question 2

SI for energy

Answer 2

Joule (kg*m^3)

pg 34

Question 3

6 power of ten prefixes

Answer 3

nano- (n) 10^-9
micro- (µ) 10^-6
milli- (m) 10^-3
centi- (c) 10^-2
Kilo (k) 10^3
mega (M) 10^6
*pg34*

Question 4

the Angstrom

Answer 4

symbol: Å.
a unit of length equal to 10^-10 m
it is convenient because atomic radii and bind lengths are typically around 1 to 3 Å
pg 35

Question 5

order of magnitude

Answer 5

factor of 10
(so if it asks by how many orders of 10 something is bigger or smaller it is asking by how many factors of 10 it is smaller of bigger)
pg 35

Question 6

density (conversion factor)

Answer 6

mass per volume
ρ = mass/volume = m/v
expressed in Kg/m^3 or g/cm^3
g/cm^3 x 1000 = Kg/m^3 or vice versa
*pg 35*

Question 7

the density of water

Answer 7

1 g/cm^3 or 1000 kg/m^3

Question 8

molecule

Answer 8

when two or more atoms form a covalent bond they create a molecule
pg 36

Question 9

Molecular formula

Answer 9

gives the identities and numbers of the atoms in the molecule. ( for ex C4H4N2)
PG36

Question 10

empirical formula

Answer 10

the smallest whole numbers that gives the same ratio of atoms from the molecular formula. so we have to divide all the subscripts in the molecular formula by their greatest common factor to get the empirical formula

example: C6H12O6 becomes CH2O
* pg36*

Question 11

Polyatomic ions

Answer 11

Ammonium (NH4+)
Hydronium (H3O+)
Acetate (AcO-) (CH3CO2-)
Bicarbonate (HCO3-)
Cyanide (CN-)
Hydroxide (OH-)
Nitrate (NO3-)
Nitrite (NO2-)
Perchlorate (CLO4-)
Carbonate (CO3 2-)
Sulfate (SO4 2-)
Sulfite (SO3 2-)
Phosphate (PO4 3-)
*pg37*

Question 12

unit for atomic weight

Answer 12

Atomic mass unit (amu)
1 amu is equal to exactly 1/12 the mass of an atom of Carbon 12 (12C)
Molecular weight (MW) is the more commonly used term in substitute of this
*pg37

Question 13

moles formula

Answer 13

mol = mass in grams/ MW

Question 14

formula weight

Answer 14

is the same as molecular weight

*pg38

Question 15

how to find percentage composition by mass

Answer 15

each element’s mass divided by the molecular weight of the compound
*pg39

Question 16

steps to find empirical formula

Answer 16

1. find the percentage composition
2. use the percentage composition as mass (ex: if there was 60% C in C4H4N2 then there is 60g of C) unless stated otherwise
3. find the moles using the mass
4. divide the moles of each element by the moles of the element with the most moles
5. the ratio you find will be the subscript. (if you divided the moles of Fe/O and you get 2/3 the answer will be Fe2O3)
   * pg40

Question 17

Molarity

Answer 17

symbolized by M. expresses the concentration of a solution in terms of moles of solute per volume (in L) of solution
M = #of mol/#liters of sol
denoted by being in [ ]
*pg 42

Question 18

Mole fraction

Answer 18

simply expresses the fraction of moles of a given substance relative to the total moles in a solution
mol fraction = #moles of substance/ total #moles in solution
*pg 42

Question 19

Law of conservation of mass/matter

Answer 19

the amount of matter does not change in a chemical reaction. the amount of matter on the right side of the arrow should equal the left side
*pg42

Question 20

what does Δ mean on top of an arrow in a reaction

Answer 20

it means that there’s heat added to the reactants (the reactants are heated) the word ‘heat’ could also be written instead of the symbol
*pg46

Question 21

catalyst

Answer 21

a substance that increases the rate of a reaction without being consumed. the presence of a catalyst is indicated by writing it below the arrow in a reaction
*pg46

Question 22

oxidation state or oxidation number

Answer 22

meant to indicate how the atom’s ‘ownership’ of its valence electrons changes when it forms a compound. giving up ownership results in a more positive oxidation state while accepting it results in a more negative state
*pg47

Question 23

ionic compounds vs covalent compounds’ oxidation states

Answer 23

ionic compounds are considered to involve the complete transfer of electrons.
for covalent compounds the oxidation state of an atom is the charge it would have if the compound were ionic
*pg47

Question 24

the 7 rules for assigning oxidation states

Answer 24

1) the oxidation state of any element in its standard state is 0
2) the sum of the oxidation states of the atoms in a neutral molecule must always be 0, and for ions it must equal the ion’s charge
3) group 1 metals have a +1 oxidation state, and group 2 metals have a +2
4) Fluorine has a -1
5) Hydrogen has a +1 when bonded to something more electronegative than C, a -1 when bonded to an atom less electronegative than a C, and 0 when bonded to C
6) oxygen has a -2 oxidation state
7) the rest of the halogens have a -1, and the atoms of the oxygen family have a -2

• rules 3 and 5 have a higher priority than 6, so something like H202 or Na2O2, Oxygen will have a -1 oxidation state
• metals can never have a negative oxidation state

*pg47

Question 25

Mnemonic for the order of electronegativities

Answer 25

FONClBrISCH (pronounced fawn-cull-brish)
in the order of the most electronegative to least electronegative
(If H is bound to something not in this list it will have a state of -1)
*pg47