C12: Chemical Analysis Flashcards

1
Q

what is a pure substance?

A

single element or compound, not mixed with any other substance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how do you know its a pure substance?

A

melt/boil at specific temps
- mixtures have range of MPs and BPs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is a formulation?

A

mixture that has been desiged as a useful product
- made my mixing components in carefully measured quanities to ensure product has required properties

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

examples of formulations ?

A

fuels, cleaning agents , paints amnd medecines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

process of chromotography?

A
  • pencil line drawn on chromotography paper/ spots of sample placed on it
  • paper lowered into solvent , making sure pencil line is above solvent
  • different substance have differnt solubility so travel at different rates (high solubility-travel further)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how can u identify if substance is pure or not from chomotography?

A

pure substance only has one spot on chromotogram
- mixtures have multiple

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how to calculate Rf value?

A

distance moved by substance/distance moved by solvent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

flame test for

Lithium?

A

crimson

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

flame test for

sodium

A

yellow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

flame test for

potassium

A

lilac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

flame test for

calcium

A

orange-red

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

flame test for

copper

A

green

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

effect of adding metal NaOH to

aluminium. calcium, magnesium

A

white precipitate
(only aluminium’s precipitate dissolves when excess NaOh is added)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

effect of adding metal NaOH to

copper

A

blue precipitate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

effect of adding metal NaOH to

iron II/iron III

A

iron II - green precipitate
iron III - brown precipitate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

test for carbonates?

A

carbonates will react with dilute acids - create CO2
- gas can be bubbled through limewater to test for CO2

17
Q

test for halides and results?

cats with brains can ideally yodel

A
  • add dilute nitric acid and silver nitrate solution
    CHLORIDE - white precipitate
    BROMIDE - Cream precipitate
    IODINE - yellow precipitate
18
Q

test for sulfates?

A

first add dilute Hcl , followed by barium chloride solution
- if sulfate ions are present, white pecipitate forms

19
Q

what do instrumental methods do and advantages?

A

detect/identify elements and compounds
- accurate
- sensitive/rapid

20
Q

what is flame emission spectroscopy?

A

instrumental method to analyse metal ions in solutions
- sample put into flame / light given out (due to electrons fallng back to energy levels) is passed through spectroscope
- results in line spectrum that can be analysed to identify metal ions/measure concentrations

21
Q

test for hydrogen, oxygen and chlorine?

A

HYDROGEN : burning splint held at open end of test tube of gas , pops
OXYGEN : glowing splint inserted into test tube of gas
- splint relights - O2

CHLORINE : damp litmus paper bleaches /turns white if present

22
Q

describe the the design and general properties of a formulation?

4mks

A

formulations are mixture designed to be useful products.
- measured quantities of components used
- each component has purpose
- giving mixture desired properties

23
Q

how does chromotography seperate dyes?

A
  • solvent moves through paper
  • different dyes have different solublities in solvent
  • and different attrcations for the paper
  • so carried different distances