foundations in chemistry

Question 1

define relative atomic mass

Answer 1

the average mass of an element compared to 1/12 mass of a carbon-12 atom

Question 2

define relative isotopic mass

Answer 2

the mass of an atom of an isotope of an element compared to 1/12 mass of carbon-12

Question 3

what is the relative atomic mass calculated from ?

Answer 3

masses of isotopes and abundance of isotopes

Question 4

what does m/z equal ?

Answer 4

mass : charge ration

Question 5

name the ion
a) OH-
b) Cl-
c) NO3-

Answer 5

a) hydroxide
b) chloride
c) nitrate

Question 6

what charge does a hydroxide (OH -) anion have ?

Answer 6

-1

Question 7

what charge does a bromide (Br -) anion have ?

Answer 7

-1

Question 7

what charge does a chloride (Cl -) anion have ?

Answer 7

-1

Question 8

what charge does a oxide (O 2-) anion have ?

Answer 8

-2

Question 9

what charge does a nitrate (NO3 -) anion have ?

Answer 9

-1

Question 10

what charge does a carbonate (CO3 2-) anion have ?

Answer 10

-2

Question 11

what charge does a sulphate (SO4 2-) anion have ?

Answer 11

-2

Question 12

what charge does a phosphate (PO4 3-) anion have ?

Answer 12

-3

Question 13

what charge does a hydrogen (H +) cation have ?

Answer 13

+1

Question 14

what charge does a sodium (Na +) cation have ?

Answer 14

+1

Question 15

what charge does a potassium (K +) cation have ?

Answer 15

+1

Question 16

what charge does a ammonia (NH4 +) cation have ?

Answer 16

+1

Question 17

what charge does a calcium (Ca 2+) cation have ?

Answer 17

+2

Question 18

what charge does a magnesium (Mg 2+) cation have ?

Answer 18

+2

Question 19

what charge does an aluminium (Al 3+) cation have ?

Answer 19

+3

Question 20

what charge does a silver (Ag +) cation have ?

Answer 20

+1

Question 21

what charge does a barium (Ba 2+) cation have ?

Answer 21

+2

Question 22

what charge does a copper [II] (Cu 2+) cation have ?

Answer 22

+2

Question 23

write the formula of sodium chloride

Answer 23

NaCl

Question 24

write the formula of magnesium chloride

Answer 24

MgCl2

Question 25

write the formula of calcium carbonate

Answer 25

CaCO3

Question 26

write the formula of ammonium carbonate

Answer 26

(NH4)2CO3

Question 27

what is a mole ?

Answer 27

an amount of a substance - a certain amount of particles it is equivalent to the number of atoms in 12g of Carbon-12

Question 28

what is avogadros constant ?

Answer 28

6.02 x 10^23

Question 29

what equation links particles, number of moles and avogadros constant ?

Answer 29

Number of particles = Avogadro constant x the amount of substance in mol

Question 30

how much does a mole weigh ?

Answer 30

a mole of a substance in grams is the same as its molecular (atomic) mass

Question 31

what equation links mass, Mr and moles ?

Answer 31

Mass = Mr x moles

Question 32

what is empirical formula ?

Answer 32

the simplest whole number ratio of atoms in a compound

Question 33

what is the empirical formula of glucose ?

Answer 33

CH2O

Question 34

what is the empirical formula of C6H4O2?

Answer 34

C3H2O

Question 35

how can empirical formula be calculated ?

Answer 35

it can be calculated from knowing the ratios in moles of the elements in a compound

Question 36

which electrons are lost when an ion is formed ?

Answer 36

the highest energy electrons

Question 37

which sub shells are exceptions to the standard rule ?

Answer 37

3d and 4s 4s fills before 3d but also empties before

Question 38

what is the electron configuration of Cr (24 electrons)

Answer 38

1s2 2s2 2p6 3s2 3p6 4s1 3d5

Question 39

what is the electron configuration of Cu (29 electrons)

Answer 39

1s2 2s2 2p6 3s2 3p6 4s1 3d10

Question 40

how do you find the location of an element ?

Answer 40

the last number in the electron config. is the period the letter is the block the number of electrons is the distance along the period

Question 41

what do ionic bonds exist in ?

Answer 41

a giant ionic lattice

Question 42

do smaller ions have stronger or weaker bonding ?

Answer 42

stronger

Question 43

what impacts attraction between ions ?

Answer 43

the charge density

Question 44

should charge density be higher or lower to increase attraction

Answer 44

higher

Question 45

what are the properties of giant ionic lattices ?

Answer 45

brittle high melting points conducts electricity when molten or in solution

Question 46

what is the relative mass of a proton ?

Answer 46

1

Question 47

what is the relative mass of an electron ?

Answer 47

1/2000

Question 48

what is the relative mass of a neutron ?

Answer 48

1

Question 49

number of protons =

Answer 49

number of electrons

Question 50

number of neutrons =

Answer 50

mass number - proton number

Question 51

number of electrons =

Answer 51

number of protons

Question 52

what determines the type of atom ?

Answer 52

the number of protons

Question 53

what are isotopes ?

Answer 53

atoms with the same number of protons but different numbers of neutrons

Question 54

how are electrons arranged ?

Answer 54

in electron shells made from SUB SHELLS

Question 55

what sub shells are in shell 1 ?

Answer 55

s

Question 56

what sub shells are in shell 2 ?

Answer 56

s p

Question 57

what sub shells are in shell 3 ?

Answer 57

s p d

Question 58

what sub shells are in shell 4 ?

Answer 58

s p d f

Question 59

what does each sub-level consist of ?

Answer 59

electron orbitals

Question 60

what are electron orbitals ?

Answer 60

regions of space in which the electrons are most likely to spend their time