GCE Acceptable Colour Changes and Observations Flashcards Preview

AS Chemistry Module 2 > GCE Acceptable Colour Changes and Observations > Flashcards

Flashcards in GCE Acceptable Colour Changes and Observations Deck (60)
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1
Q

What colour is fluorine gas?

A

Yellow

2
Q

What colour is chlorine gas?

A

Green

3
Q

What colour is bromine liquid?

A

Red-brown

4
Q

What colour is bromine gas?

A

Red-brown vapour

5
Q

What colour is iodine solid?

A

Grey-black

6
Q

What colour is iodine vapour?

A

Violet / purple

7
Q

What colour is chlorine water?

A

Green / colourless

8
Q

What colour is bromine water?

A

Yellow / orange / brown

9
Q

What colour is iodine solution in a polar solvent?

A

Yellow / brown

10
Q

What colour is iodine solution in a non-polar solvent?

A

Violet / purple

11
Q

Give an example of a non-aqueous solvent

A

Hexane

12
Q

What are the observations when solid fluoride is reacted with concentrated sulfuric acid?

A

Steamy / misty fumes (of HF) produced

13
Q

What are the observations when solid chloride is reacted with concentrated sulfuric acid?

A

Steamy / misty fumes (of HCl) produced

14
Q

What are the observations when solid bromide is reacted with concentrated sulfuric acid?

A

Steamy / misty fumes (of HBr) produced

Red-brown vapour (Br2) produced

15
Q

What are the observations when solid iodide is reacted with concentrated sulfuric acid?

A
Steamy / misty fumes (of HI)
Violet / purple vapour (I2)
Smell of rotten eggs (H2S)
Yellow solid (S)
Grey-black solid (on the sides of the test-tube) (I2)
16
Q

What are the observations when solid fluoride is reacted with concentrated phosphoric acid?

A

Steamy / misty fumes (of HF)

17
Q

What are the observations when solid chloride is reacted with concentrated phosphoric acid?

A

Steamy / misty fumes (of HCl)

18
Q

What are the observations when solid bromide is reacted with concentrated phosphoric acid?

A

Steamy / misty fumes (of HBr)

19
Q

What are the observations when solid iodide is reacted with concentrated phosphoric acid?

A

Steamy / misty fumes (of HI)

20
Q

What colour is phenolphthalein in acidic solutions?

A

Colourless

21
Q

What are the two main indicators for acid-base titrations?

A

Phenolphthalein and methyl orange

22
Q

What colour is phenolphthalein in neutral solutions?

A

Colourless

23
Q

What colour is phenolphthalein in alkaline solutions?

A

Pink

24
Q

What colour is methyl orange indicator in acidic, neutral and alkaline solutions?

A
Acidic = red
Neutral = orange
Alkaline = yellow
25
Q

What indicator is suitable for titrations with a strong acid-strong base or a weak acid-strong base?

A

Phenolphthalein

26
Q

What indicator is suitable for titrations with a strong acid-strong base or a strong acid-weak base?

A

Methyl orange

27
Q

What is the colour change at endpoint of methyl orange when adding acid to alkali?

A

Yellow to red

Alkali in conical flask, acid in burette

28
Q

What is the colour change at endpoint of methyl orange when adding alkali to acid?

A

Red to yellow

Acid in conical flask, alkali in burette

29
Q

What is the colour change at endpoint of phenolphthalein when adding alkali to acid?

A

Colourless to pink

Acid in conical flask, alkali in burette

30
Q

What is the colour change at endpoint of phenolphthalein when adding acid to alkali?

A

Pink to colourless

Alkali in conical flask, acid in burette

31
Q

What is the test for hydrogen gas?

A

Gives a ‘pop’ with a burning splint

32
Q

What is the test for carbon dioxide gas?

A

Bubble through limewater, limewater turns milky

33
Q

What is the test for chlorine gas?

A

Turns damp blue litmus paper red (due to HCl and HClO), then bleaches it (due to HClO)

34
Q

What is the test for oxygen gas?

A

Relights a glowing splint.

35
Q

What is the test for HCl?

A

Dip a glass rod in conc. ammonia. In the presence of hydrogen chloride gas, dense white fumes (NH4Cl, ammonium chloride) will be produced.

36
Q

What is the test for NH3?

A

Dip a glass rod in conc. HCl. In the presence of ammonia gas, dense white fumes (NH4Cl, ammonium chloride) will be produced.

37
Q

What colour will lithium ions appear in a flame test?

A

Crimson

38
Q

What colour will sodium ions appear in a flame test?

A

Yellow / orange

39
Q

What colour will potassium ions appear in a flame test?

A

Lilac

Pink through cobalt glass

40
Q

What colour will calcium ions appear in a flame test?

A

Brick red

41
Q

What colour will barium ions appear in a flame test?

A

Apple green

42
Q

What colour will copper ions appear in a flame test?

A

Blue-green

43
Q

What is the test for ammonium ions?

A

Warm with a solution of sodium hydroxide. A pungent smell will be observed.

44
Q

What is the test for sulfate ions?

A

SO4 2-

Make a solution and add a solution of barium chloride or barium nitrate - forms a white precipitate.

45
Q

What is the test for halide ions?

A

Make a solution in dilute nitric acid and add silver nitrate solution, then note the following:

Cl- ion = white precipitate, soluble in dilute ammonia solution.
Br- ion = cream precipitate, soluble in concentrated ammonia solution.
I- ion = yellow precipitate, insoluble in concentrated ammonia solution.

46
Q

What is the test for carbonate ions?

A

Add dilute acid to from colourless gas which turns limewater milky.

47
Q

What is the test for iodine?

A

Add a few drops of starch to the solution, the solution will turn blue-black.

48
Q

What are the observations when a hydrocarbon is burnt?

A

A smoky/sooty flame is indicative of a high carbon content and for incomplete combustion.

49
Q

What is the test for alkenes?

A

Test for unsaturation

Add a few cm^3 of bromine water. After shaking the aqueous layer will decolourise.

50
Q

What are the observations when an alcohol is burnt?

A

A non-smoky/non-sooty/clean blue flame is indicative of complete combustion/low carbon content.

A sooty/smoky flame is indicative of incomplete combustion/high carbon content.

51
Q

What are the observations when an alcohol is reacted with sodium?

A

Solid disappears, fizzing, mixture warms up.

52
Q

What are the observations when an alcohol is reacted with phosphorus pentachloride?

A

Solid disappears, steamy/misty fumes, mixture warms up, hissing noise.

53
Q

What are the observations when an alcohol is oxidised?

A

Primary and secondary alcohols with acidified potassium/sodium dichromate (VI) solution changes from orange to green when heated, change in smell.

54
Q

What are the observations when magnesium is reacted with water?

A

Few bubbles produced slowly, metal dulls

55
Q

What are the observations when calcium is reacted with water?

A

Fizzing, mixture warms up, metal rises and falls, metal disappears, white solid produced.

56
Q

What are the observations when magnesium/calcium is reacted with hydrochloric acid?

A

Metal disappears, fizzing, mixture warms up

57
Q

What are the observations when magnesium is reacted with sulfuric acid?

A

Metal disappears, fizzing, mixture warms up

58
Q

What are the observations when calcium is reacted with sulfuric acid?

A

Fizzing initially but reaction stops (due to formation of insoluble calcium sulfate)

59
Q

What are the observations when magnesium is burnt in oxygen?

A

Bright white light to form a white powder.

60
Q

What are the observations when calcium is burnt in oxygen?

A

Brick red flame to form a white powder