Alkali Group 2 Metals and halogens

Question 1

What is the trend in group 2 metals going down the periodic table in atomic size

Answer 1

The atomic size increases as going down group 2 as the number of outer shells increases

Question 2

What is the trend for in first ionisations energy in group 2 elements going down the group

Answer 2

First ionisation energy decreases going down group 2 as the outer shells are more shielded from the nucleus by the inner electrons so they are held less closely and so are easier to remove

Question 3

What is the trend in electronegativity going down group 2

Answer 3

Electronegativity decreases as the outer shells are shielded from the nucleus and so the attraction reduced

Question 4

State the trend in melting points of elements going down group 2

Answer 4

The melting points of the elements decrease going down group 2 as the attraction between the cations and delocalised electrons decreases due to atom getting bigger

Question 5

What is produced when MG reacts with steam and give the equation

Answer 5

Mg+2H20->Mg(oh )+H2

It reacts with steam

Question 6

Give the equations for when strontium and barium react with cold water

Answer 6

Sr+2H2O->Sr(OH)+H2

Ba+2H2O->Ba(OH)+H2

Question 7

State the trend in solubitly of sulphates in group 2 and give the most soluble and insouble

Answer 7

Solubility of sulphates decreases going down group 2

I.e. Ba(+2) + SO4-BaSO4

MgSO4 is soluble and SrSO4 and BaSO4 are insoluble

Question 8

What two alkali metals don’t react with water and which one react with steam

Answer 8

Be and Mg

Mg reacts with steam

Question 9

What is produced when Ba reacts with sulphate ions

Answer 9

Thick white precipitate (barium meal)

Question 10

How would u test for sulphate ions

Answer 10

Add barium chloride,dilute HCL and the unknown solution

If a white precipitate forms sulphate ions are present

Question 11

When testing for sulphate ions why is HCL added

Answer 11

To remove other ions like hydroxide ions and carbonate ions as they may affect the test

Question 12

State the solubility of hydroxides in group 2

Answer 12

Solubility increases going down group 2

Mg+2 OH->MgO+ H2

Ca+2H2O->Ca(OH)2+H2

Question 13

What can magnesium hydroxide be used for

Answer 13

As it’s almost insouble it’s used in milk of magnesia for indigestion

Question 14

What is calcium hydroxide used for

Answer 14

In slaked lime in order to neutralise acidic soil

Question 15

What is barium sulphate used for

Answer 15

It’s used in a barium meal in the gut where it can absorb x rays and it’s completely insouble

Question 16

Give the order of electronegativity in group 7 from highest to lowest

Answer 16

F
Cl
Br
I

Question 17

Give the order of the strongest oxidising agents in group 7

Answer 17

F
Cl
Br
I

Question 18

Why does oxidising power increase going group 7

Answer 18

As their are fewer number of shells in the atom,so electrons are closer to the nucleus and are less shielded,this means the attraction of electrons to the nucleus is stronger and so the atom is more likely to accept electrons

Question 19

State the trend in reducing power going down group 7 and why

Answer 19

Reducing power increases with iodine being the strongest reducing agent as the atom gets larger so the outer electrons are further away from the nucleus and so less attracted

Question 20

What is meant by displacement reactions

Answer 20

This is when halogens that are the strongest oxidising agent wil displace more reactive halides(reducing agents)

Question 21

What happens when chlorine displaces both bromine and iodine and give the equations

Answer 21

CL2 +2Br- ->2CL- +Br2 and orange colour will appear

CL2 +2I->2Cl- +I2
And a brown colour will appear

Question 22

What happens when bromine displaces iodine

Answer 22

Br2+2I–>2Br- +I2

A brown colour will appear

Question 23

What is seen when Cl is reacted with H2SO4 and state the type of reaction it is

Answer 23

White fumes of HCL are produced

The fumes will turn blue litmus paper red

Acid base reaction

Question 24

What is produced with Bromine reacts with H2SO4 and state what happens to the sulphuric acid

Answer 24

Red colour of bromine
White fumes that can turn litmus paper red
HBR is made

Sulphuric acid is reduced to sulphur dioxide +6 to +4

Bromine Increases from -1 to 0

Question 25

What is produced when iodine reacts with H2SO4 and state what happens to the sulfur

Answer 25

White fumes that will turn blue litmus paper red Purple colour or iodine Smell of rotten eggs due to H2S Sulfur reduced from +6 to -2 H2SO4 reduced to H2S

Question 26

In reactions with the halides what does the concentrated sulphuric acid behave as

Answer 26

An oxidising agent

Question 27

When reacted with sliver ions and nitric acid state the precipitates formed when reacted with halide ions

Answer 27

Chlorine will produce a white precipitate Bromine a cream precipitate Iodine a yellow precipitate AgNo3 +Br- -> AgBr

Question 28

Why is nitric acid added

Answer 28

To ensure that an hydroxide ions or impurities are removed

Question 29

State how we can distinguish between the precipitate that halide ions form and give the reactions with each halide ion

Answer 29

We add ammonia If dilute or conc ammonia is added to AgCl the precipitate will dissolve If conc ammonia is added to Agbr the precipitate is soluble AgI is insouble in conc ammonia

Question 30

Give the equation when chlorine reacts with water and state the type of reaction it is

Answer 30

CL2 +H20->HCL +HClo It's disproportionation as the chlorine is simultaneously oxidised and reduced

Question 31

Give advantages and disadvantages of using chloride acid

Answer 31

It kills Bactria in Pools It's toxic and can cause cancer

Question 32

Why isnt dilute HCL or H2SO4 used to acidify silver nitrate

Answer 32

They would give off different precipitates Ie sliver sulfate will form and sliver chloride which invalidates the test H2SO4 forms white precipitate of sliver chloride that will invalidate the test

Question 33

What is the use of Cao(caoh)

Answer 33

To remove So2 from flue gas in a process called neutralisation

Question 34

State why magnesium is used instead to extract titanium instead of carbon

Answer 34

As titanium reacts with carbon to form another product so it's reacts with carbon and chlorine first

Question 35

State why magnesium is used instead to extract titanium instead of carbon

Answer 35

As titanium reacts with carbon to form another product so it's reacts with carbon and chlorine first

Question 36

Give the equation for the reaction of mg and ticl4

Answer 36

TiCl4+2Mg-Ti+2MgCl2

Question 37

What happens when cold dilute chlorine is added to sodium hydroxide and give the equation

Answer 37

Sodium chlorate forms which is used as bleach 2NaOH+CL2-> NaClO +Nacl +H2O

Question 38

What do both the reaction of chlorine with water and naoh have in common

Answer 38

They are both disproportionation reacts in which chlorine is simultaneously reduced and oxidised