Foundations in Chemistry

Question 1

what is relative atomic mass?

Answer 1

the weighted mean mass of an atom compared to 1/12 of a C-12 atom

Question 2

what is an isotope?

Answer 2

different forms of the same element with same proton and electron numbers but different neutron number

Question 3

what is ionic bonding?

Answer 3

the electrostatic attraction between oppositely charged ions

Question 4

what is covalent bonding?

Answer 4

the electrostatic attraction between bonding electrons and the nuclei of bonded atoms

Question 5

what is metallic bonding?

Answer 5

electrostatic attraction between positive ions and delocalised electrons

Question 6

what is relative isotopic mass?

Answer 6

the mass of an isotope compared to 1/12 of a C-12 atom

Question 7

what is molecular formula?

Answer 7

the actual number of elements in a compound

Question 8

what is empirical formula?

Answer 8

the smallest number ratio of elements in a compound

Question 9

how many electrons can be in the first shell?

Answer 9

2

Question 10

how many electrons can be in the second shell?

Answer 10

8

Question 11

how many electrons can be in the third shell?

Answer 11

18

Question 12

how many electrons can be in the fourth shell?

Answer 12

32

Question 13

what are the four orbitals called?

Answer 13

s, p, d, f

Question 14

what is an orbital?

Answer 14

a region around a nucleus of an atom that can hold up to 2 electrons of opposite spins

Question 15

what is the shape of an s-orbital?

Answer 15

spherical

Question 16

what is the shape of a p-orbital?

Answer 16

3D dumbbell

Question 17

what is the formula for ammonium?

Answer 17

NH4 (+)

Question 18

what is the formula for silver?

Answer 18

Ag (+)

Question 19

what is the formula for zinc?

Answer 19

Zn (2+)

Question 20

what is the formula for hydroxide?

Answer 20

OH (-)

Question 21

what is the formula for nitrate?

Answer 21

NO3 (-)

Question 22

what is the formula for manganate(VII)?

Answer 22

MnO4 (-)

Question 23

what is the formula for hydrogencarbonate?

Answer 23

HCO3 (-)

Question 24

what is the formula for hydrogensulfate?

Answer 24

HSO4 (-)

Question 25

what is the formula for carbonate?

Answer 25

CO3 (2-)

Question 26

what is the formula for sulfate?

Answer 26

SO4 (2-)

Question 27

what is the formula for dichromate?

Answer 27

Cr2O7 (2-)

Question 28

what is the formula for phosphate?

Answer 28

PO4 (3-)

Question 29

what is an acid?

Answer 29

proton donor

Question 30

what is a base?

Answer 30

proton acceptor

Question 31

what is an alkali?

Answer 31

base that releases OH- ions when dissolved in water

Question 32

what is a strong acid?

Answer 32

completely dissociates into its ions in aq solutions

Question 33

what is a weak acid?

Answer 33

partially dissociates into its ions in aq solutions

Question 34

what is a salt?

Answer 34

produced when the H+ ion of an acid is replaced by a metal ion/NH4 (+)

Question 35

how to work out number of particles?

Answer 35

moles x avogadros constant

Question 36

how to work out moles?

Answer 36

mol = mass / Mr

Question 37

how to work out percentage yield?

Answer 37

actual mass/mol / theoretical mass/mole x 100

Question 38

how to work out atom economy?

Answer 38

Mr of desired product / Mr of all products x 100

Question 39

how to work out mole from volume and conc?

Answer 39

mole = conc x vol (/1000)

Question 40

how to work out mole from volume?

Answer 40

mole = vol / 24/24000

Question 41

what is hydrated?

Answer 41

when water of crystallisation is present in a compound

Question 42

what is anhydrous?

Answer 42

when water of crystallisation is removed from a compound?

Question 43

what is water of crytallisation?

Answer 43

water present in a compound giving it a crystalline appearance

Question 44

what is reduction?

Answer 44

gain of e-

Question 45

what is oxidation?

Answer 45

loss of e-

Question 46

what is disproportion?

Answer 46

when an element is reduced and oxidised

Question 47

what is the oxidising agent?

Answer 47

reagent that is reduced

Question 48

what is the reducing agent?

Answer 48

reagent that is oxidised

Question 49

why is metallic bonding good conductor?

Answer 49

mobile e- can carry charge

Question 50

why is aqueous ionic bonding good conductor?

Answer 50

mobile ions can carry charge

Question 51

what is a dative covalent bond?

Answer 51

when one atom provides both electrons being shared

Question 52

what is average bond enthalpy?

Answer 52

measurement of covalent bond strength

Question 53

what is the bond angle of a linear shape?

Answer 53

180 degrees

Question 54

what is the bond angle of a tetrahedral shape?

Answer 54

109.5 degrees

Question 55

what is the bond angle of a trigonal planer shape?

Answer 55

120 degrees

Question 56

what is the electron-pair repulsion theory?

Answer 56

- bonding pairs repel as far apart as possible - lone pairs repel more than bonding pairs

Question 57

what is the bond angle of an octohedral?

Answer 57

90 degrees

Question 58

how to work out bond angle of shape with lone pairs?

Answer 58

minus 2.5 from bond angle of shape

Question 59

why makes a molecule non-polar?

Answer 59

- symmetrical shape - dipoles cancel out - no net dipole across molecule

Question 60

what makes a molecule polar?

Answer 60

- asymmetrical shape - dipoles dont cancel out - one element is more electronegative

Question 61

which molecules have induced dipole-dipole forces?

Answer 61

non-polar covalent molecules

Question 62

which molecules have permanent dipole forces?

Answer 62

polar covalent molecules (without H-N, H-F, H-O)

Question 63

which molecules have hydrogen bonds?

Answer 63

polar covalent molecules with H-N, H-F, H-O

Question 64

how to show a hydrogen bond?

Answer 64

dashed line

Question 65

which IMF is strongest to weakest?

Answer 65

- hydrogen - permanent - induced

Question 66

what are the two properties of water?

Answer 66

- ice is less dense than water due to further apart hydrogen bonds - water has higher than expected mp/bp due to relatively strong hydrogen bonds

Question 67

which covalent molecules are giant?

Answer 67

- diamond - graphene - silicon dioxide - silicon - buckminster fullerene