(blue) Halogens Flashcards

(blue) Halogens

1
Q

what are the gp 7 elements in the periodic table

A

there called halogens , they are highly reactive , only exsits as compounds in nature

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

how do gp7 elements for ions

A

they loose electrons the form halide ions

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

what type of bond do they most likly form

A

covalent

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

propertys of fluorine :
formula of molecule

A

F2

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

propertys of fluorine :
Appearance and state at room temp

A

Pale yellow gas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

propertys of fluorine :
Electron

configuration

A

1s2 2s2 2p5

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

propertys of fluorine :
Bleaching

ability

A

Very strong

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

propertys of fluorine :
Solubility in

water and

appearance of
solution

A

Reacts with water to form HF and O2

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

propertys of chlorine :
Formula of

molecule

A

Cl2

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

propertys of chlorine :
Appearance

and state at

room temp

A

Green/yellow gas

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

propertys of chlorine :
Electron

configuration

A

1s2 2s2 2p6 3s2 3p5

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

propertys of chlorine :
Bleaching

ability

A

Strong

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

propertys of chlorine :
Test for the gas

A

Damp blue litmus paper Turns red then bleached Or Damp starch iodide paper Turns blue

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

propertys of chlorine :
Solubility in

water and

appearance of

solution

A

Slight solubility but also reacts to form chlorine water HCl and HOCl Pale green soln.

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

Trend in
solubility in
H2O of Cl2 to I2

A

decreses in solubnility

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

propertys of chlorine :
Solubility in

cyclohexane

and appearance

of solution

A

Soluble Yellow/green solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

propertys of bromine :
Formula of

molecule

A

Br2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

propertys of bromine :
Appearance

and state at

room temp

A

Dark red/brown liquid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

propertys of bromine :
Bleaching

ability

A

Weak

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

propertys of bromine :
Test for the gas

A

Damp starch + iodide paper Turns blue Bubble through KI solution with starch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

propertys of bromine :
Solubility in

water and

appearance of

solution

A

Slight solubility but also reacts to form bromine water HBr and HOBr Orange solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

propertys of bromine :
Solubility in

cyclohexane

and appearance

of solution

A

Soluble red solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

propertys of iodine :
Formula of

molecule

A

I2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

propertys of iodine :
Appearance

and state at

room temp

A

Shiny grey solid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

propertys of iodine :
Electron

configuration

A

[Kr] 5s2 4d10 5p5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

propertys of bromine :
Electron

configuration

A

[Ar] 4s2 3d10 4p5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

propertys of iodine :
Bleaching

ability

A

none

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

propertys of iodine :
Test for the gas

A

Starch solution turns blue/black

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

propertys of iodine :
Solubility in

water and

appearance of

solution

A

Almost insoluble producing a very pale brown solution. Soluble in KI solution à dark brown solution.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

propertys of iodine :
Solubility in

cyclohexane

and appearance

of solution

A

Soluble purple solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

describe the general trend in bleaching ability down the halogens

A

gets weaker

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

describe the general trend solubility on water down the group for halogens

A

F2 soluable , however rest is all silightly soluable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

State, and explain the change in melting pts down .group 7

A

Increases, as the number of electrons increases the London forces also increase (IMF) requiring more energy to overcome.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

State and explain the change in electronegativity down group 7.

A

Decreases, outer electrons are progressively more shielded from the nucleus as the atomic radius increases, also the distance between the bonding pair and nucleus increaces. (proton number increaes but this is more than offset by the other factors) So electrons in a covalent bond are attracted less to the halogen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

State and explain the change in reactivity of the Group 7 elements down group 7

A

As most reactions with halogens result in the halogen gaining an electron. They become less reactive on descending. Reactivity decreases as atomic radius increases and more shielding means electrons attracted less strongly to the nucleus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is the problem in distinguishing between bromine and iodine solutions?

A

Depending on concentration both could appear a brown/orange colour.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

How could you show that you have a solution of iodine? Give two methods.

A

· Add an organic solvent and shake. Halogens are more soluble in organic solvents, Iodine —-> purple colour in upper, organic layer, bromine —-> red organic layer

· Add starch solution and shake. Iodine —->blue / black.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

how would you seperate bromine from iodine in a seperating funnel

A

add organinc solvent e.g hexane

shake and allow to settle
iodine moves to hexane layer

open tap and run off iodine layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

most metals react with halogens to make what

A

ionic compounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Mg(s) + Cl2(g) —–> MgCl2(s)
which one has been oxidised and which has been reduced

A

What has been oxidised :Magnesium

What has been reduced? chlorine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

when Cl , br and I react with AL to what charge does AL get oxidised to

A

Al —-> Al 3+ + 3e -

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

aluminium + bromine

what are the :
Observations

Oxidation equation

Reduction equation

A

Bromine liquid dropped on Aluminium foil. Sparks and glowed red Got hot and a lot of bromine vapour evolved. A white solid remained.

Oxidation equation Al(s) —–> Al3+ + 3e-

Reduction equation Br2 + 2e- —-> 2Br-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

aluminium + iodine:

what are the :
Observations

Oxidation equation

Reduction equation

A

Vigorous reaction, clouds of purple I2vapour. Solid glowed red-hot Grey solid AlI3 remaine

Oxidation equation : Al(s) —-> Al3+ + 3e-

Reduction equation: I2 + 2e- ——> 2I-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

how do halogens oxidise Fe 2+

A

Fe 2+ goes to Fe 3+

halogens are also reduced to halide ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

what is the Observation on adding Fe2+ to Cl2

also what is the reduction , oxi and redox reaction

A

Solution became very pale yellow (thiocyanate —-> red therefore Fe3+ present)

reduction : Cl2 + 2e- —-> 2Cl-

oxi : Fe2+—–> Fe3+ + e-

redox Cl2 + 2Fe2+ —–> 2Fe3+ + 2Cl-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

what is the Observation on adding Fe2+ to Br2

also what is the reduction , oxi and redox reaction

A

Solution became very pale yellow (thiocyanate ——> red therefore Fe3+ present)

reduction : Br2 + 2e- —–> 2Br-

oxi : Fe2+ ——> Fe3+ + e-

redox : Br2 + 2Fe2+ ——> 2Fe3+ + 2Br-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

what is the Observation on adding Fe2+ to I2

also what is the reduction , oxi and redox reaction

A

No change (thiocyanate ——-> unchanged - no Fe3+)

reduction + oxi + redox : none as no reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

what is a test to test for Fe 3+

A

Additional test for Fe3+ = add potassium thiocyanate (KSCN) a red colour indicates Fe3+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

what is the colour of KCl

A

colourless solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

what is the colour of KBr

A

colourless solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

what is the colour of KI

A

colourless solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

what happens when you mix
chlorine with KCl

A

nothing

as Cl cannot oxidise its self

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

what happens when you mix
chlorine with KBr

A

colourless solution turns pale yellow

hexane —-> red

this is because Cl oxidises the Br

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

what happens when you mix
chlorine KI

A

colourless solution turn orange brown

henane —-> purple

this is because Cl oxidises the Br

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

what happens when you mix
bromine with chlorine

A

just a dilution of the orange colour

Br cannot oxidise Cl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

what happens when you mix
bromine with Br

A

nothing as Br cannot oxidise its self

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

what happens when you mix
bromine with KI

A

turned dark orange ,

starch —-> blue/black

Br can oxidise I from KI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

what happens when you mix
iodine with KCl / KBr /KI

A

nothing there will just be a dilution of the origonal colour as iodine cannot oxidise any of the halide ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Does chlorine (Cl2) oxidise
Br- (aq)
I- (aq)

A

yes
yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Does bromine (Br2) oxidise
Cl- (aq)
I- (aq)

A

no for Cl

yes for I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Does iodine (I2) oxidise
Cl- (aq)
Br- (aq)

A

no
no

62
Q

give the oxidation half equation for when chlorine oxidises Br

then give a full redox equation

A

Oxidation of bromide ions

2Br-(aq) —–> Br2(aq) + 2e-

Oxidation of bromide ions by chlorine

Cl2(aq)+2Br-(aq) ——–> Br2(aq)+2Cl-(aq)

63
Q

give the oxidation half equation for when chlorine oxidises iodine

then give a full redox equation

A

Oxidation of iodide ions

2I-(aq) —–> I2(aq) + 2e-.

Oxidation of iodide ions by chlorine

Cl2(aq)+2I-(aq) —— >I2(aq)+2Cl-(aq

64
Q

give the oxidation half equation for when bromine oxidises iodide

then give a full redox equation

and give reduction half equation

in KI

A

Oxidation half equation

2I-(aq) —–> I2(aq) + 2e-

Reduction half equation

Br2(aq) + 2e- ——> 2Br-(aq)

full redox equation of bromine and iodide

Br2(aq) + 2KI(aq) —–> I2(aq) + 2KBr(aq)

65
Q

Put the halogens in order of their oxidising ability and explain the trend.

A

Cl2 > Br2 > I2 Chlorine is able to oxidise both bromide and iodide, it has fewest electon shells with least shielding and smallest radius so has the strongest ability to attract the electron from iodide or bromide.

66
Q

give the definition of a disproportionation reaction

A

A disproportionation reaction is: the simultaneous oxidation and reduction of an atom of the same element in an ion or molecule.

67
Q

though halogens are sparingly soluable , it can sometimes dissolve in water

give that equation

A

Cl2+ H2O —–> HCl + HOCl

68
Q

Use oxidation numbers to show that this is a disproportionation reaction

Cl2+ H2O —–> HCl + HOCl

A

Chlorine is simmultaneously oxidised from 0 in Cl2 to +1 in HOCl and reduced from 0 in Cl2 to -1 in HCl

69
Q

what is the observation of adding Naoh to Cl2

A

turned colourless, negative test for Cl2

70
Q

what is the observation of adding Naoh to Br2

A

turned colourless

71
Q

what is the observation of adding Naoh to I2

A

turned colourless

72
Q

give the general formula for halogens reacting with cold alkali

A

X2 (g) + 2NaOH (aq) → NaX (aq) + NaXO (aq) + H2O

73
Q

Write ionic equations for the disproportionation reactions of:- leave out spectator ions

bromine with cold alkali

A

Br2 + 2OH- —-> Br - + OBr - + H2O

74
Q

Write ionic equations for the disproportionation reactions of:- leave out spectator ions

iodine with cold alkali

A

I2 + 2OH- —> I- + OI- + H2

75
Q

give the reaction of Cl with HOT alkali

also give the ionic equation

A

3Cl2 (aq) + 6NaOH (aq) → 5NaCl (aq) + NaClO3 (aq) + 3H2O (l)

ionic

3Cl2 (aq) + 6OH- (aq) → 5Cl- (aq) + ClO-3 (aq) + 3H2O (l)

Ionic equation (leaving out Na+ spectator ions).

76
Q

Write full equations for the disproportionation reactions of iodine with hot sodium hydroxide (including spectator ions)

A

3I2 (aq) + 6NaOH (aq) → 5Nal (aq) + NalO3 (aq) + 3H2O (l)

77
Q

Write full equations for the disproportionation reactions of bromine with hot sodium hydroxide (including spectator ions)

A

3Br2 (aq) + 6NaOH (aq) → 5NaBr (aq) + NaBrO3 (aq) + 3H2O (l)

78
Q

Write ionic equations for the disproportionation reactions of iodine and bromine with hot alkali (leaving out spectator ions).

A

iodine : 3I2 (aq) + 6OH- (aq) → 5l- (aq) + lO3- (aq) + 3H2O (l)

Bromine: 3Br2 (aq) + 6OH- (aq) → 5Br- (aq) + BrO3- (aq) + 3H2O (l)

79
Q

info card (read and recite)

A

Hydrogen chloride gas is very soluble in water, reacting with it to produce hydrochloric acid. The familiar steamy fumes of hydrogen chloride in moist air are caused by the hydrogen chloride reacting with water vapour in the air to produce a fog of concentrated hydrochloric acid.

80
Q

give the equation for when HCL reacts with water

A

HCl(g) + H2O(l) → HCl (aq) → H+(aq) + Cl- (aq)

81
Q

what are the observations of reacting conc ammonia and conc HCl

A

Observations

Hydrogen chloride gas forms steamy fumes in moist air due to HCl dissolving in water droplets and forming HCl(aq).

HCl(g) forms a white smoke with NH3(g), this is solid NH4Cl particles

82
Q

what is the equation of reacting conc ammonia and conc HCl

A

NH3(g) + HCl(g) → NH4Cl (s)

83
Q

give examples of metal halides

A

NaCl, NaBr, NaI

84
Q

Two types of reaction can take place when metal halides (e.g.NaCl, NaBr, NaI) react with conc H2SO4

what are they

A

· Redox reactions forming Cl2, Br2 or I2

· Displacement reactions forming HCl, HBr or H

85
Q

info card (read and recite)

A

We already know that the ability of the halogens Cl2, Br2 and I2 to gain electrons varies. The halogen which gains electrons most easily is chlorine This is, therefore the strongest oxidising agent.

It follows that the halide ions Cl-, Br- and I- will have differing ability to lose electrons. Which halide ion will lose electrons most easily? iodide. This is, therefore the strongest reducing agent.

Concentrated sulphuric acid contains the sulfate (VI) ion of formula/charge SO42- . The S in this ion has oxidation number +6

86
Q

how do you test for HCl

A

use NH3

87
Q

after adding KCl with H2SO4 what are the observations

also what are the gases evolved

A

Vigorous became hot (exothermic) Steamy fumes litmus à red. Acidic gas Fumes produced white smoke when tested with NH3 and white ppt with AgNO3

gases evolved
HCl

88
Q

after adding KBr with H2SO4 what are the observations

also what are the gases evolved

A

Vigorous became hot (exothermic) Steamy fumes litmus —-> red. Acidic gas Fumes produced white smoke when tested with NH3 Orange vapour Gas turned orange dichromate(VI) paper or solution green.

gases evolved :
HBr Br2 and SO2 Cr(VI) has been reduced to Cr(III) by SO2 gas

89
Q

after adding KI with H2SO4 what are the observations

also what are the gases evolved

A

Very Vigorous became very hot Steamy fumes —–> white smoke + NH3 Brown black deposits Acidified dichromate —–> green. Lead ethanoate à black

gases evolved:
HI(g) I2 , SO2(g) , H2S(g)

90
Q

give the equation for the displacement reaction of conc. sulphuric acid with sodium chloride

A

H2SO4 + NaCl → NaHSO4 (s) + HCl(g)

NOTE: There is no change in the oxidation numbers of any species.

This is the only reaction for a metal chloride with concentrated sulphuric acid.

91
Q

give the reaction of KBr with sulfuric acid

is HBr oxidising or reducing agents?

A

KBr + H2SO4 → KHSO4 + HBr displacement

2HBr + H2SO4 → Br2 + 2H2O + SO2 redox

reducing agent

92
Q

give the reaction of KI with sulfuric acid

is HI oxidising or reducing agents?

A

KI + H2SO4 → KHSO4 + HI displacement

8HI + H2SO4 → H2S + 4H2O + 4I2 redox

reducing agents

93
Q

Explain why iodides react differently from chlorides.

A

(hydrogen) iodide is more easily oxidized / loses electrons more easily than (hydrogen) chloride because it has a larger radius (than chloride).

94
Q

which is stronger when reacting with sulfuric acid

HI / HBr / HCl

A

HI(g) can reduce S in H2SO4 from +6 to -2 in H2S

Whereas HBr only reduces S in H2SO4 from +6 to +4 in SO2.

95
Q

what are the observations of adding silver nitrate and HNO3 to Cl

A

white ppt

96
Q

what are the observations of adding silver nitrate and HNO3 to Br

A

cream ppt

97
Q

what are the observations of adding silver nitrate and HNO3 to I

A

yellow ppt

98
Q

what are the observations of adding excess dilute NH3 to a silvernitrate solution for Cl

A

Ppt. dissolved with dil.NH3

99
Q

what are the observations of adding excess dilute NH3 to a silvernitrate solution for Br

A

Ppt. dissolved in CONC NH3

100
Q

what are the observations of adding excess dilute NH3 to a silvernitrate solution for I

A

Ppt. did not dissolve

101
Q

Write ionic equations for the reactions between silver ions and halide ions, including the states of matter.

A

Chloride: Ag+(aq) + Cl-(aq) —>AgCl(s)

Bromide: Ag+(aq) + Br-(aq) —> AgBr(s)

Iodide Ag+(aq) + I-(aq) —> AgI(s)

102
Q

Suggest why dilute nitric acid was added to the silver nitrate solution. Think what other precipitates it might dissolve.

A

Prevents precipitation of silver hydroxide, oxide or carbonate which would interfere with the observations.

103
Q

How does adding NH3 allow you to identify the precipitate?

to Agcl

A

It allows confirmation of precipitate as AgCl is soluble in both dil and conc NH3, AgBr is only soluble in conc. NH3 and Agl is insoluble in NH3

104
Q

what is the effect on silver nitrate solutions with the halogens

A

AgCl - Decomposes to silver (goes lilac)
AgBr - Decomposes slowly to silver(grey)
AgI - No change

105
Q

Silver chloride and silver bromide react with ammonia solution to form a complex ion

give the equation

A

AgCl(s) + 2NH3(aq) —> [Ag(NH3)2]+(aq) + Cl-(aq)

106
Q

Silver chloride and silver bromide decompose on exposure to light

giev the equation

A

2AgCl(s) —–> 2Ag(s) + Cl2(g)

107
Q

how do you test for a CO3 2- group

and also the observation you would see

A

add HCL , effervescence and colourless solution produced

108
Q

how do you test for a HCO3 - group

and also the observation you would see

A

On heating / boiling the solution without acid a gas is produced.

109
Q

what gas has evolved from CO3 2- when adding HCl , and/or boiling HCO3 -

and how would you test for this gas

A

Bubble through limewater which would give a white ppt./turn cloudy

110
Q

Give the reaction including state symbols for the reaction between the carbonate and the acid

A

Na2CO3(aq) + 2HCl (aq) ——> 2NaCl(aq) + H2O(l) + CO2(g)

111
Q

Give an ionic equation for the reaction between carbonate and hydrogen ions

A

CO32-(aq) + 2H+(aq) ——-> H2O(l) + CO2(g)

112
Q

Give the reaction including state symbols for the reaction between the hydrogencarbonate and the acid

A

NaHCO3(aq) + HCl (aq) ———> NaCl(aq) + H2O(l) + CO2(g)

113
Q

Give an ionic equation for the reaction between the hydrogencarbonate ion and hydrogen ions

A

HCO3-(aq) + H+(aq) ———> H2O(l) + CO2(g)

114
Q

what are the observation of adding SO4 2- and dil HCL

then after that adding BaCl2 (barium chloride)

A

colourkess solution produced

immediate thick white ppt

115
Q

Give the equation for the reaction between barium chloride and sodium sulfate, including state symbols.

A

Na2SO4(aq) + BaCl2(aq) ——> BaSO4(s) + 2NaCl(aq)

116
Q

Give an ionic equation for the reaction between sulfate and barium ions

A

SO42-(aq) + Ba2+(aq) ——-> BaSO4(s)

117
Q

info (read and recite)

A

Note. Addition of barium chloride to a carbonate will give a white precipitate of barium carbonate. However, if HCl is added to the anion solution before BaCl2(aq) then only the sulfate(VI) SO42- will form a precipitate.

118
Q

after adding NaOH to NH4 + and heating gently what are the observations

A

Gas given off, smell of NH3

119
Q

after adding NaOH to NH4 + and heating gently what are the observations when putting it infrom of DAMP red litmus paper

A

Turned blue

120
Q

after adding NaOH to NH4 + and heating gently what are the observations when putting it infrom of DAMP Blue litmus paper

A

no change

121
Q

give the equation between NH4 + and NaOH

A

NH4+ + OH- —–>NH3 + H2O

122
Q

info (read and recite)

A

The warming (of NH4+ and NaOH) releases the ammonia gas, which is detected by the litmus paper. This is a example of an acid/base reaction which you will study next year.

123
Q

give the test and observation for:
Li+

A

test :
Flame test Clean nichrome wire in HCl and use non-luminous flame Dip in HCl then solid. Hold at edge of non-luminous flame

obsvation :
Red

124
Q

give the test and observation for:
Na+

A

test :
Flame test Clean nichrome wire in HCl and use non-luminous flame Dip in HCl then solid. Hold at edge of non-luminous flame

obsvation :
Persistent yellow orange

125
Q

give the test and observation for:
K+

A

test :
Flame test Clean nichrome wire in HCl and use non-luminous flame Dip in HCl then solid. Hold at edge of non-luminous flame

obsvation :
lilac

126
Q

give the test and observation for:
Ba 2+

A

test :
Flame test Clean nichrome wire in HCl and use non-luminous flame Dip in HCl then solid. Hold at edge of non-luminous flame

obsvation :
apple green

127
Q

give the test and observation for:
Sr 2+

A

test :
Flame test Clean nichrome wire in HCl and use non-luminous flame Dip in HCl then solid. Hold at edge of non-luminous flame

obsvation :
red

128
Q

give the test and observation for:
Ca 2+

A

test :
Flame test Clean nichrome wire in HCl and use non-luminous flame Dip in HCl then solid. Hold at edge of non-luminous flame

obsvation :
yellow - red

129
Q

give the test and observation for:
Mg 2+

A

test :
To a solution add dil.NaOH

observation :

White ppt of Mg(OH)2(s) Mg2+(aq) + 2OH-(aq) ——> Mg(OH)2(s)

130
Q

give the test and observation for:
NH4 +

A

test
To a solution add dil.NaOH, warm, and test gas with red litmus OR Heat the solid

observation

NH4+(aq) + OH-(aq) ——-> NH3(g) + H2O(l) NH3 alkaline gas NH4+ sublimes producing a white solid further up the test tube.

131
Q

give the test and observation for:
Cl -

A

test :
1)Acidify with dil HNO3 Add AgNO3 dropwise To the ppt. add dil NH3 followed by conc. NH3

2)Add a few drops of conc H2SO4 to the solid sample

3) To 2cm3 of the sample add chlorine water until no further changes.

observation :

1)White ppt of AgCl, Soluble in NH3

2) Steamy fumes HCl

132
Q

give the test and observation for:
Br -

A

test :
1)Acidify with dil HNO3 Add AgNO3 dropwise To the ppt. add dil NH3 followed by conc. NH3

2)Add a few drops of conc H2SO4 to the solid sample

3) To 2cm3 of the sample add chlorine water until no further changes.

observation

1) Cream ppt of AgBr, Soluble in conc. NH3
2) Steamy fumes of HBr + Orange fumes of Br2
3) Solution turns orange

133
Q

give the test and observation for:
I -

A

test :
1)Acidify with dil HNO3 Add AgNO3 dropwise To the ppt. add dil NH3 followed by conc. NH3

2)Add a few drops of conc H2SO4 to the solid sample

3) To 2cm3 of the sample add chlorine water until no further changes.

observation

1) Yellow ppt of AgI, insoluble in conc. NH3
2) Steamy fumes of HI + Black solid I2
3) Solution turns brown

134
Q

give the test and observation for:
SO4 2-

A

test :
Add BaCl2(aq) dropwise followed by HCl(aq)

observation :
White ppt produced BaSO4. Ba2+(aq) + SO42-(aq) —-> BaSO4(s) Unchanged with HCl

135
Q

give the test and observation for:
CO3 2-

A

test :
Add acid, test gas by bubbling through limewater.

observation :
Effervescence —-> colourless solution Gas turns limewater milky

136
Q

give the test and observation for:
HCO3 -

A

test :
Heat aqueous solution

observation :
Effervescence, lime water ——> milky

137
Q

give the test and observation for:
Oxygen

A

· Put a glowing spill into a test tube of the gas.
· It will relight

138
Q

give the test and observation for:
carbon dioxide

A

· Bubble the gas through a solution of .limewater
· This will go cloudy / form a white ppt

139
Q

give the test and observation for:
Ammonia

A

· Smelly gas. Damp red litmus goes blue
· With HCl gas white smoke is produced

140
Q

give the test and observation for:
Nitrogen dioxide

A

· This is a brown coloured gas
· Damp blue litmus goes red

140
Q

give the test and observation for:
HYdrogen

A

· Put a lighted spill into a test tube of the gas.
· It will give a squeaky pop

141
Q

give the test and observation for:
HYdrogen

A

· Put a lighted spill into a test tube of the gas.
· It will give a squeaky po

142
Q

give the test and observation for:
Hydrogen chlordie

A

· Steamy fumes. Damp blue litmus goes red
· With NH3 gas white smoke is produced
· When bubbled into AgNO3(aq) a white precipitate forms

143
Q

give the test and observation for:
Hydrogen bromide

A

· Steamy fumes. Damp blue litmus goes red
· With NH3 gas white smoke is produced
· When bubbled into AgNO3(aq) a cream coloured precipitate

144
Q

give the test and observation for:
Hydrogen iodide

A

· Steamy fumes. Damp blue litmus goes red
· With NH3 gas white smoke is produced
· When bubbled into AgNO3(aq) a yellow precipitate forms

145
Q

give the test and observation for:
Cl2

A

· Smells of bleach
· Damp blue litmus paper goes red then bleached · Damp starch/iodide paper —-> blue
· Turns KBr (aq) from colourless to yellow / orange

146
Q

give the test and observation for:
Br2

A

· Vapour is orange in colour.
· Turns KI (aq) from colourless to brown

147
Q

give the test and observation for:
I2

A

· Vapour is purple in colour. Solid is gray
· Turns starch soln. from white to blue/black

148
Q

give the test and observation for:
Water vapour

A

· Anhydrous copper(II)sulfate goes from white to blue

149
Q

give the test and observation for:
Sulfur dioxide

A

· Acidified potassium dichromate solution goes from orange to green/blue

150
Q

give the test and observation for:
Hydrogen sulfide

A

· Rotten egg smell.
· Lead(II) nitrate solution goes from colourless to black