Module 2 - foundations of chemistry (year 1)

Question 1

What is the ideal gas constant?

Answer 1

8.31 J/mol K

Question 2

Waht is Avogardo’s constent?

Answer 2

6.02x10^23

Question 3

What is the bond angle and name of a molecule with:
2 Bone pairs
0 Lone pairs

Answer 3

Linear 180^o

Question 4

What is the name and bond angle of a molecule with:
3 Bond pairs
0 Lone pairs

Answer 4

Trigonal planer 120^o

Question 5

What is the name and bond angle of a molecule with:
4 bond pairs
0 lone pairs

Answer 5

Tetraheldral 109.5^o

Question 6

What is the name and bond angle of a molecule with:
6 bone pairs
0 lone pairs

Answer 6

Octehedral 90^o

Question 7

What is the name and bond angle of a molecule with:
3 bone pairs
1 lone pair

Answer 7

Triagonal Pyramidal 107^o

Question 8

What is the name and bond angle of a molecule with:
2 bond pairs
2 lone pairs

Answer 8

Bent/ Non-linear 104.5^o

Question 9

Define reletive isotopic mass

Answer 9

The mass of one isotope compared to 1/12 the mass of a carbon-12 atom

Question 10

Define reletive atomic mass

Answer 10

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

Question 11

Define reletive molecular mass

Answer 11

The average mass of a molecule compared to 1/12 the mass of a carbon-12 atom

Question 12

What is the equation for reletive atomic mass

Answer 12

R.A.M = total(isotopic mass x % abundance)/100

Question 13

Define a mole

Answer 13

The mass of a substance in grams, when there is the same number of atoms as the number of atoms in 12 grams of carbon-12

Question 14

How do you calculate empirical formula?

Answer 14

1- divide each mass or mass percentage by their atomic mass
2- divide each number by the smallest number
3- (sometimes) multiply to make each number whole

Question 15

How many electrons can a P orbital hold?

Answer 15

6 electrons

Question 16

How many electrons can an S orbital hold?

Answer 16

2 electrons

Question 17

How many electrons can a D orbital hold?

Answer 17

10 electrons

Question 18

How many electrons can an F orbital hold?

Answer 18

14 electron

Question 19

How many electrons can the second priciple energy level hold?

Answer 19

8 electrons

Question 20

How many electrons can the third principle energy level hold?

Answer 20

18 electrons

Question 21

How many electrons can the fourth principle energy level hold?

Answer 21

32 electrons

Question 22

What are the limitations of the Octet rule?

Answer 22

It only applied to the first three periods

Question 23

What is the Octet rule?

Answer 23

A theory that the shells of an atom can hold a maximum of 2,8,8 electrons respectively. This is actually the 1S orbital, 2S and 2P orbitals, then 3S and 3P orbitals.

Question 24

What is a spectator ion?

Answer 24

An ion which does not change state or oxidation number

Question 25

What does an ionic equation exclude?

Answer 25

Spectator ions

Question 26

What is the normal oxidation number of group 1 metals?

Answer 26

+1

Question 27

What is the normal oxidation number of a group 2 metal?

Answer 27

+2

Question 28

What is the normal oxidation state of Aluminium?

Answer 28

+3

Question 29

What is the normal oxidation number of Hydrogen? | What is the exception?

Answer 29

+1, unless in a metal hydride such as NaH

Question 30

What is the normal oxidation number of Fluorine? | What is the exception?

Answer 30

-1, flourine never has an exception

Question 31

What is the normal oxidation number of Bromine, Clorine and Iodine? What is the exception?

Answer 31

-1, unless in a compound with Fluorine or Oxygen

Question 32

What is the normal oxidation number of Oxygen? | What is the exception?

Answer 32

-2, unless in a compound with Fluorine or in hydrogen peroxide (H2O2)

Question 33

How close do titre value have to be to be considered concordent results?

Answer 33

0.10cm^3

Question 34

How does too much indicator effect the titration?

Answer 34

The indicator contains a weak acid which slightly effects the ph of the solution. Only two to three drop should be used. Too much indicator would lead to slighlt lower titres (if the acid is in the burette).

Question 35

how does the jet effect the titration?

Answer 35

If the jet is not full then there will be a slightly higher titre than normal. The burette should be run with the acid or base to fill the jet.

Question 36

How do you wash the equitment before a titrtation?

Answer 36

Wash the conical flask with distilled water, the burette with the acid or base being used, and the other equipment with distilled water.

Question 37

How do you calculate %uncertainty?

Answer 37

%uncertainty = (uncertainty/average measurement) x100

Question 38

How do you calculate amount (mole)

Answer 38

mole(mol)= mass(g) / mr

Question 39

What is the name given to water in a crystal compound?

Answer 39

water of crystalisation

Question 40

How do you calculate concentration?

Answer 40

concentration (mol/dm^3) = amount (mol) / volume (dm^3)

Question 41

How do you calculate mass conentration?

Answer 41

mass concentration (g/dm^3) = mass (g) / volume (dm^3)

Question 42

What is the ideal gas equation?

Answer 42

PV=nRT | pressure (Pa) x volume (m^3) = amount (mol) x gas constent (JK^-1 mol^-1) x temperature (K)

Question 43

How do you convert celcius to kelvin?

Answer 43

+273

Question 44

How do you calculate atom econemy?

Answer 44

Atom econemy = (mass of usefull products / mass of reatents) x100

Question 45

Define an inoic bond?

Answer 45

The electrostatic attraction between tow oppersitely charged ions, formed by electron transfers.

Question 46

Define a covalent bond?

Answer 46

the electrostatic attraction between a shared pair of electrons and the nucli of the bonded atoms

Question 47

What is a dative bond?

Answer 47

A covalent bond, except all of the shared electrons come from one atom.

Question 48

What are the properties of a giant ionic lattice?

Answer 48

Good conductor of electricity but only when liquid Good solubility in water High boiling point Usually crystal solids.

Question 49

What are the properties of simple covalent molecules?

Answer 49

poor eletrical conductivity Poor solubility in water Low boiling point Usually a gas at room temperature

Question 50

What properties increase the atrractivity of a posetive ion?

Answer 50

Small atomic radius Low sheilding High nuclear charge

Question 51

What properties increase the attractivity of a negative ion?

Answer 51

Large atomic radius High sheilding Low atomic charge

Question 52

What increases the attractivity of a covalently bonded atom?

Answer 52

Low atomic radius Low sheilding High nuclear charge

Question 53

Define electonegativity

Answer 53

The relative tendancy of an atom in a covalent bond to attract electrons to itself.

Question 54

What factor effects induced dipole dipole forces (London forces)?

Answer 54

The more elctrons their are the stronger the dipoles become

Question 55

What does Van der waal's forces reffer to?

Answer 55

Both induced and perminate dipole dipole forces

Question 56

What does a hydrogen bond form between?

Answer 56

A hydrogen atom and the lone pair of oxygen, fluorine or nitrogen.