organic chemical analysis 7

Question 1

what is crude oil

Answer 1

a fossil fuel formed millions of years ago from the decay of dead sea creatures. It is a mixture of hydrocarbons

Question 2

what are features of Alkanes

Answer 2

fully saturated
ends in ANE
c has 4 single bounds

Question 3

general formula of Alkanes

Answer 3

CnH2n+2

Question 4

first 5 alkanes

Answer 4

Meth
Eth
Prop
But
Pent

Question 5

what are the properties of short chain hydrocarbons

Answer 5

small molecules
low boiling point
high volatility
low viscosity
high flamability

Question 6

what are the properties of long chain hydrocarbons

Answer 6

large molecules
high boiling point
low volatility
high viscosity
low flammability

Question 7

what is viscosity

Answer 7

how easily it flows

Question 8

What is a fraction

Answer 8

a set of hydrocarbon molecules of similar size and boiling point

Question 9

what is the processes of a fractionating column

Answer 9

Tower is hot at bottom,
all gases condense at different temperatures
The different fractions are collected as liquids at different temps
Smaller molecules have low boiling points and are collected at the top

Question 10

what is produced in combustion

Answer 10

carbon dioxide + water

Question 11

what is produced in incomplete combustion

Answer 11

carbon + carbon monoxide + water

Question 12

what does oxidised mean

Answer 12

adding oxygen to produce an oxide

Question 13

what is catalytic cracking

Answer 13

heat to vaporise at a low pressure
go over catalytic cracker to crack the hydrocarbons
goes into the distillation tower

Question 14

What are the features of Alkenes

Answer 14

double bound
unsaturated
reactive

Question 15

General formula of Alkenes

Answer 15

CnH2n

Question 16

what is produced when a long alkane is cracked

Answer 16

short alkane + alkenes

Question 17

Definition of pure

Answer 17

a pure substance is one that is made up of just one substance. That substance can be either an element or a compound

Question 18

Melting and boiling points of a pure substance

Answer 18

specific temps(fixed points)

Question 19

Melting and boiling point of an impure substance

Answer 19

do not have sharp melting and boiling points

Question 20

What are formulations

Answer 20

are mixtures designed to produce a useful product

Question 21

What is chromatography

Answer 21

used to separate substances in a mixture when all substances are soluble in the same solvent

Question 22

How to measure Retention Factor

Answer 22

Distance moved by sample/distance moved by solvent

Question 23

how to test for hydrogen

Answer 23

squeaky pop

Question 24

how to test for oxygen

Answer 24

relight blow out splint

Question 25

how to test for chlorine

Answer 25

litness paper bleaches

Question 26

metal + acid makes

Answer 26

metal salt + hydrogen

Question 27

hydrogen peroxide reacted by magnesium oxide makes

Answer 27

water + oxygen

Question 28

metal carbonate + acid makes

Answer 28

metal salt + water + carbon dioxide

Question 29

what is the flame test

Answer 29

test for various metal ions by heating your substance and seeing whether it burns with a distinctive colour flame

Question 30

flame color of Lithium

Answer 30

crimsom

Question 31

flame color of Sodium

Answer 31

yellow

Question 32

flame color of Potassium

Answer 32

lilac

Question 33

flame color of Calcium

Answer 33

orange-red

Question 34

flame color of Copper

Answer 34

green

Question 35

flame test proccess

Answer 35

clean a wire loop by dipping it in a dilute HCL and hold it over a blue flame Dip the loop into the sample and record the color of the flame You use the color to identify the ions It only works on samples that contain a single metal ion

Question 36

what is the colored precipitate test

Answer 36

adding a few drops of sodium hydroxide solution to a solution of the mystery compound to form a insoluble hydroxide

Question 37

why does the colored precipitate test work

Answer 37

many metal hydroxides are insoluble and precipitate out of solution when formed.

Question 38

color of copper precipitate in the colored precipitate test

Answer 38

blue

Question 39

color of Iron 2 plus precipitate in the colored precipitate test

Answer 39

green

Question 40

color of iron 3 plus precipitate in the colored precipitate test

Answer 40

brown

Question 41

color of aluminium precipitate in the colored precipitate test

Answer 41

white

Question 42

color of magnesium precipitate in the colored precipitate test

Answer 42

white

Question 43

ionic equation of the colored precipitate test on calcium

Answer 43

Ca 2 plus + 2OH minus = Ca(OH)2

Question 44

ionic equation of the colored precipitate test on calcium

Answer 44

Ca 2 plus + 2OH minus = Ca(OH)2

Question 45

how do you know if sulfate ions are produced

Answer 45

white precipitate

Question 46

how do you know if carbonate ions are produced

Answer 46

CO2 produced/limewater turns cloudy

Question 47

how do you know if halide ions are present for Iodide Bromide Chloride

Answer 47

yellow cream white

Question 48

what and how does flame emission spectroscopy work

Answer 48

finds out what ions are present from there wavelengths a sample is placed in a flame. As the ions heat up their electrons become excited. When the electrons drop back to their original levels they transfer light as energy. This passes through a spectroscope which can detect different wavelengths of light to produce a line spectrum

Question 49

how does flame emission spectroscopy determine the ions present

Answer 49

combinations of wavelength emitted by an ion depends on it's charge and it's electron arrangement. Each ion has a different wavelength.

Question 50

what does the intensity of flame emission spectroscopy show

Answer 50

indicates the concentration of that ion

Question 51

flame emission spectroscopy for mixtures what does it show

Answer 51

can be used to show more than one ion present

Question 52

advantages of instrumental analysis

Answer 52

``` time saving more accurate sensitive fast small ```

Question 53

disadvantages of instrumental analysis

Answer 53

expensive | needs training

Question 54

disadvantage of non instrumental

Answer 54

large less accurate less sensitive larger sample needed