General

Question 1

What is the test for 3° alcohols to isolate them from 1 and 2

Answer 1

Add K2Cr2O7 (stays orange for 3°, 1° and 2° react so colour changes to green

Question 2

Equation for enthalpy change of formation

Answer 2

(Sign) mass of Liquid x 4.18 x change in temp/1000 x lim moles

Question 3

Define enthalpy change of formation

Answer 3

Enthalpy change when 1 mole of a substance is formed from its elements under standard conditions

Question 4

Define Enthalpy change of combustion

Answer 4

Enthalpy change when one mole of a substance is completely combusted under standard conditions

Question 5

Equation for enthalpy change of combustion

Answer 5

(Negative) (mass of H2O x 4.18 x change in temp)/(1000 x mol fuel)

Question 6

Effect of ozone in stratosphere

Answer 6

Absorbs high energy UV

Question 7

Effect of ozone in troposphere

Answer 7

Photochemical smog, respiratory problems

Question 8

Physical properties of haloalkanes

Answer 8

Covalent bonding, simple molecular structure, usually liquid at RTP, don’t mix well with water

Question 9

Group 2 physical properties

Answer 9

High mpt/bpt, density greater than group 1 elements

Question 10

Group 2 reaction with water observations

Answer 10

Silver solid reacts with effervescence to produce cloudy solution (alkaline)

Question 11

Group 2 oxides reaction with H2O?

Answer 11

Produces hydroxides

Question 12

Acid + Base -> ?

Answer 12

Salt + Water

Question 13

Group 2 trends down group

Answer 13

Solubility of Carbonates decreases, everything else increases (reactivity, thermal stability etc.)

Question 14

How are emission spectra formed

Answer 14

Atom heated to high temperature, electrons excited to higher energy level, energy given out as em rad when electrons drop back down, rad passed through prism coloured lines seen

Question 15

How are absorption spectra formed

Answer 15

White light passes through cooled sample of gas, energy absorbed to raise electrons to higher energy levels, rad passed through prism, black lines show missing frequencies

Question 16

What shape are s and p orbitals

Answer 16

S - spherical, P - dumbbell shaped

Question 17

What are subshells

Answer 17

Groups of orbitals of the same type

Question 18

Define covalent bonding

Answer 18

Electrostatic attraction between shared pairs of electrons and two positive nuclei

Question 19

Exceptions to covalent bonding rule

Answer 19

H forms 1 bond, Be forms 2 cov bonds, Al forms 3 cov bonds, S can form 2 or 6, P can form 3 or 5

Question 20

Define metallic bonding

Answer 20

Electrostatic attraction between a lattice of positive ions and a sea of delocalised electrons

Question 21

Define ionic bonding

Answer 21

Electrostatic attraction between ions of opposite charges

Question 22

What structure do ionic compounds have

Answer 22

Giant 3D lattice

Question 23

How do ionic compounds dissolve in water

Answer 23

Water molecules cluster around the ions, positive ions are attracted to O and negative ions attracted to H, water molecules overcome bonds in the compound and pull the ions apart

Question 24

Define stereoisomerism

Answer 24

Compounds with the same structural formula but with a different arrangement

Question 25

What are E/Z isomers

Answer 25

When there is no free rotation about the C=C bond, with two different groups attached to each C atom including one H on each carbon

Question 26

Conditions for cracking

Answer 26

500°c, Al2O3 catalyst, no O2

Question 27

How do homogenous catalysts work

Answer 27

Reactant gas absorbs on the catalysts surface Bonds in reactant molecules are weakened and break New product bonds form The product molecules desorb from the surface

Question 28

Physical properties of alkanes

Answer 28

Low mpt/bpt Insoluble in water Soluble in organic solvents Less dense than water

Question 29

Chemical properties of alkanes

Answer 29

Generally unreactive Non polar Strong C-C and C-H bonds

Question 30

How to balance half equations

Answer 30

Balance atoms other than O and H Add H2O to balance O Add H+ to balance H Add e- to balance charge

Question 31

How do IdId bonds form

Answer 31

Electrons constantly moving Causes uneven distribution of charge Causes instantaneous dipole in 1 Induces other dipoles in neighbouring molecules

Question 32

What are PdPd bonds

Answer 32

Attraction between molecules with permanent dipoles Only in polar molecules

Question 33

Which solvents do polar/nonpolar molecules dissolve in

Answer 33

Polar dissolves in polar Nonpolar dissolves in nonpolar

Question 34

How do PdId bonds form

Answer 34

A permanent dipole can induce a temporary one in a species that is normally non polar such as HCl and Cl2

Question 35

What is Hydrogen Bonding

Answer 35

A type of strong PdPd bond Electrostatic attraction between a very delta+ H atom and a LP of e- on a N O or F atom Very high mpt bpt Strength depends on electronegativity and number of H bonds

Question 36

What radiation does the sun emit

Answer 36

Mainly UV with some visible

Question 37

What is a nucleophile

Answer 37

A negative or partially negative species that forms a dative bond by donating a pair of electrons

Question 38

Define electronegativity

Answer 38

A measure of the ability of an atom to attract the bonding pair of electrons in a covalent bond to itself

Question 39

Solubility of Nitrates and Ethanoates

Answer 39

All are soluble

Question 40

Solubility of Sulphates

Answer 40

All soluble except BaSO4, PbSO4, CaSO4

Question 41

Solubility of Halides

Answer 41

All soluble except AgX and PbX

Question 42

Solubility of Carbonates

Answer 42

All insoluble except Na, K, NH4

Question 43

Solubility of Hydroxides

Answer 43

All insoluble except Li, Na, K, Ca

Question 44

Solubility of Oxides

Answer 44

All insoluble Group 1 and 2 oxides react with water to form hydroxides

Question 45

Carbonate test

Answer 45

Add an acid, effervescence Bubble gas through lime water Goes from colourless to cloudy white

Question 46

Sulphate test

Answer 46

Nitric acid and Barium nitrate White precipitate

Question 47

Halide ion test

Answer 47

Nitric Acid, Silver Nitrate Cl- White Precipitate Br- Cream precipitate I- Yellow precipitate

Question 48

Physical properties of alcohols

Answer 48

Polar Higher mpt/bpt than alkanes Small alcohols are water soluble

Question 49

Define ionisation energy

Answer 49

Energy needed to remove 1 electron from each atom in 1 mole of gaseous atoms

Question 50

What order should anion tests be carried out (Sulphate, Carbonate, Halide)

Answer 50

Carbonate Sulphate Halide