Alkali Metals Group 1 + Halogens Group 7 Flashcards

1
Q

Why are alkali metals highly reactive (2 reasons)

A

Because they only have one electron in the outer shell
And have a large atomic radius so electrons are held less strongly to thr positive nuclei (because further away from positive nucleus)

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2
Q

Do alkali metals have low or high boiling/melting points and explain why?

A

Low boiling/melting point
Because electrons in the outer shell are held weakly to the positive nuclei due to its large atomic radius
So electrostatic forces of attraction are weaker so less energy is required to break the bonds
(between the sea of delocalized electrons and the positive nuclei)

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3
Q

Do alkali metals have low or high densities? Can any float on water?

A

Low densities

Lithium, sodium potassium can float

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4
Q

Why do alkali metals all have similar properties

A

Because they have one electron in their outershell

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5
Q

Give two physical properties of alkali metals

A

Shiny when freshly cut but quickly tarnish

Soft to cut with a knife

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6
Q

What kind of solution do all alkali metals form with water

A

Alkaline solutions

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7
Q

What is the word equation for an alkali metal with water

A

Alkali metal + water —-) metal hydroxide + hydrogen

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8
Q

Write the balanced symbol equation for the reaction between potassium and water with state symbols

A

2K(s) + 2H20———) 2KOH(aq) + H2(g)

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9
Q

Give two properties of all metal hydroxide solutions

A

Aqeous

colourless

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10
Q

Write the balanced symbol equation with state symbols of reaction between Lithium and water

A

2Li(s) + 2H20(l) ——-) 2LiOH(aq) + H2(g)

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11
Q

Describe 4 observations from the reaction of lithium and water and explain why they happen(4)

A
  • fizzes steadily because hydrogen is given off
  • Lithium does not melt
  • Relatively slow reaction
  • eventually dissapears
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12
Q

Describe four observations from the reaction between sodium and water and explain why (3)

A
  • Fizzes rapidly
  • Melts to form a ball( because a lot of heat is released)
  • ball moves across the surface (because hydrogen catches fire) and eventually dissapears
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13
Q

Describe 5 observations from the reaction between potassium and water and explain why (5)

A
  • fizzes very rapidly
  • Melts into a shiny ball- because a lare amount of heat is released
  • dashes quickly across the surface - because hydrogen catches fire
  • Burns to form a lilac flame- because a large amount of heat released
  • sometimes there is an explosion
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14
Q

What kind of hazard could happen if alkali metal is in contact with water

A

Would be corrosive and could cause burns

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15
Q

Why are alkali metals stored in oil

A

To prevent them reacting with oxygen or water

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16
Q

Does the density increase or decrease down the group of alkali metals

A

Density increases

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17
Q

Why do alkali metals tarnish/corrode when exposed to air

A

Because they form metal oxides when reacted with oxygen

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18
Q

What does metal oxide look like on an alkali metal

A

A dull coating over the surface

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19
Q

Is rubidium less dense than water

A

No it is more dens

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20
Q

What is the word equation for the reaction between alkali metals and oxygen

A

Alkali metal + oxygen —-) metal oxide

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21
Q

What is the symbol equation for the reaction between sodium and oxygen with state symbols

A

4Na(s) + O2(g) ——-) 2Na2O(s)

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22
Q

What is the balanced symbol equation for the reaction between Potassium and oxygen with state symbols

A

4K(s) + O2(g) ——) 2K2O(s)

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23
Q

Predict the melting point, density and reaction between water of rubidium

A

Melting point is lower than potassium
Density is higher than potassium
Reacts more vigorously and explosively than potassium

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24
Q

Does the melting/boiling point of the halogens increase or decrease as you go down the group and explain why?

A

Melting/ boiling point increases
Because molecular mass increases
So the intermolecular forces of attraction become stronger
And more energy is required to break them

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25
Q

Does the reactivity of the halogens increase or decrease as you go down a group and explain why

A

Reactivity decreases
Because atomic radius gets larger of each atom
so forces of attraction between the positive nuclei and shared electrons are weaker

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26
Q

Why are halogens gases at the top of the group but solids at the bottom of the group

A

Because boiling and melting point increases as you go down so more energy is required to break the intermolecular forces of attraction

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27
Q

Are halogens good conductors of heat and electricty? Explain why

A

Poor conductors of heat and electricty
Because covalent substances
So no delocalized electrons

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28
Q

What is the physcial state at room temperature of fluorine

A

Gas

29
Q

What is the physical state at room temperature of chlorine

A

Gas

30
Q

What is the physical state at room temperature of bromine

A

Liquid

31
Q

What is the physical state at room temperature of iodine

A

Solid

32
Q

Predict what the physical state at room temperature is of astatine

A

Solid

33
Q

What colour is fluorine at room temperature

A

Yellow

34
Q

What colour is astatine at room temperature

A

Black

35
Q

What colour is iodine at room temperature

A

Dark grey

36
Q

What colour is bromine at room temperature

A

Dark Orange

37
Q

What colour is chlorine at room temperature

A

Yellow- Green

38
Q

What colour is iodine when heated (when its in vapour form)

A

Purple

39
Q

Does the density of halogens increase or decrease as you go down

A

Density increases

40
Q

What happens when a halogen and hydrogen react

A

A hydrogen halide is formed

41
Q

What forma when a hydrogen halide is dissolved in water

A

an acid

42
Q

Write the balanced symbol equation for the reaction between hydrogen chloride and water

A

HCl(g) + H2O(l)——) HCL (aq)

43
Q

Write the balanced symbol equation for the reaction between hydrogen and chlorine

A

H2(g) + Cl2(l) ——) 2HCl(g)

44
Q

What is the product of the reaction between bromine and hydrogen(in words)

A

Hydrogen bromide

45
Q

What is the general word equation for the reaction between a halogen and a metal

A

Halogen + metal——-) metal halide

46
Q

What does a metal halide look like

A

A salt

47
Q

What is another word for a metal halide

A

An ionic salt

48
Q

What type of substance is formed when a halogen reacts with a non metal

A

A covalent compound

49
Q

Wht is the word equation between fluorine and potassium chloride

A

Potassium chloride + fluorine ——) potassium fluoride + chlorine

50
Q

Explain why iodine is able to be displaced by chlorine

A

Because chlorine is more reactuve than iodine

51
Q

Describe what the colour change is from the reaction between potassium chloride + fluorine

A

to green

52
Q

Chlorine is added to a solution of a compound of another group seven element.
There was a reaction and the colour changed from green to grey
Identify the group seven element present

A

Iodine

53
Q

What colour flame is produced when lithium burns

A

Red flame

54
Q

What is hazadous about the halogens

A

All have poisonous vapours

55
Q

Would you see a observe a flame when there is a reaction between lithium and water or sodium and water

A

No

Only if you burn to test for the gas

56
Q

Describe how could you test that a solution of lithium hyrdroxide is alkaline

A

Use red litmus paper

It should turn blue

57
Q

Why can lithium nitride not conduct electricty

A

Because ionic compounds can only conduct electricty when molten, so when ions are free to move

58
Q

State two similarities and one difference between the reaction of lithium in water and the reaction of sodium in water

A

They both fizz(effervesence)
They both dissolve and dissapear

But lithium does not melt
And sodium melts into a ball

59
Q

Why does LiOH turn blue on red litmus paper

A

Because LiOH is an alkaline solution as OH- ions are present

60
Q

Chlorine reacts witn hydrogen to form hydrogen chloride. This is then dissolved in water, and a ribbon of magnesium is added
State the positive ion
And the negative ion formed
And the gas that is formed

A

Positive = Mg2+
Negative= Cl -
Gas= hydrogen
(Because remember that hydrogen chloride in water is hydrochloric acid and then a metal and an acid makes metal salta and hydrogen)

61
Q

Suggest why there is no reason to add chlorine to lithium chloride solution

A

Because halogens do not react with their own halides

62
Q

When chlorine reacts with potassium iodide solution, what is the substance that produces a brown colour

A

Iodine

63
Q

When there is a displacement reaction between bromine and potassium iodide, does bromine displace iodine or does bromine disolace iodide

A

Bromine displaces iodine

64
Q

What colour does damp litmus paper turn in chlorine gas and why

A

White
Becuase chlorine reacts with water to form an acidic solution which acts as a bleach
(Halogen + water = acidic solution)

65
Q

Which halogen has the palest colour

A

Chlorine

66
Q

If metal X reacts with aluminum nitrate and there is no colour change, is metal X more reactive than aluminum or less reactive

A

Less reactive

67
Q

If i add zinc to a solution of copper nitrate, and then there is a layer of layer thin coating over the zinc, what is the substance that causes this

A

Copper

68
Q

When magnesium reacts with an aqeous solution of silver nitrate, a redox reaction occurs.
State in terms of electrons which species is the oxidizing agent and explain why

A

Silver ions
Because they are being reduced and gaining electrons
So are taking them away from magnesium ions

69
Q

If you add phenothalepin, to a solution of potassium hydroxide, what colour does it turn and why

A

Pink

Because of the presence of OH- ions