3.2 Inorganic Chemistry: .2 Group 2, the alkaline earth metals Flashcards Preview

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Flashcards in 3.2 Inorganic Chemistry: .2 Group 2, the alkaline earth metals Deck (23):
1

how many electrons do all group 2 elements have in their outer shell?

2 electrons

2

how does a group 2 element become and ion? and what sort of ion does it become?

it loses 2 electrons to form a
2+ ion

3

what is the trend in atomic radius down the group? why?

-the atomic radius increases down the group
-this is because the elements get bigger getting an extra main energy level compared with the one above it

4

what is the trend in ionisation energy as you go down the group?

-the ionisation energy decreases down the group
-this is because as you go down the group the elements gain an extra shell so the
-outer electron is more shielded from the nucleus
-meaning that the attraction between the nucleus and outer electron get weaker
-therefore less energy is required to remove the outer electron from the atom

5

what is the trend in melting point as you go down the group?

-the melting point generally decreases down the group
this is because;
-going down the group the metal ions get bigger
-the larger the ionic radius the further away the delocalised electrons are from the positive nuclei and the less attraction they feel
-weaker electrostatic force as you go down the group
-so it requires less energy to break the bonds

6

what is produced when Magnesium reacts with water

M(s?) + 2H2O(l)--> M(OH)2(aq) + H2(g)

*this is the same for all reaction just substitute the element

7

does barium react with water?

no

8

what is produced when Magnesium reacts with steam?

Mg + H2O(steam) --> MgO + H2

*this is the same for all reaction just substitute the element

9

what is the trend in solubility with hydroxides going down the group?

the metals hydroxides increase in solubility as you go down the group

(* remember sIngly charged ions e.g [OH-] Increase in solubility)

10

is Magnesium insoluble or soluble in water

-magnesium reacts with water to form Magnesium hydroxide which is almost insoluble (sparingly insoluble)
-(Mg+ and OH-, two small ions hold tight)

11

what is the trend in solubility with Sulfate ions going down the group?

the metal sulfate decrease in solubility down the group

(* remember Doubly charged negative ions e.g (SO2-) Decrease in solubility down the group)

12

give the ionic equation for the formation of Barium Sulphate and state whether it is soluble or insoluble

Ba2+(aq) + SO42-(aq) --> BaSO4 (s)
-barium sulphate is insoluble

13

describe the test for a sulphate ion and state what you see

-you first acidify the solution with hydrochloric acid or nitric acid to get rid of any sulphites or carbonates (CO32-) which could also produce a white precipitate
e.g NaCO3 + 2HCL --> 2NaCl + H2O + CO2
-then you add barium chloride solution and if the sulphate is present a white precipitate of barium sulphate is formed

14

I am adding barium chloride to Iron sulphate, produce an equation for this reaction

BaCl2 (aq) + FeSO4 (aq) --> BaSO4 (s) + FeCl2(aq)

15

(edit) I am adding barium Nitrate to Iron sulphate, produce an equation for this reaction

Ba(NO3)2 + FeSO4 (aq) --> BaSO4 (s) + Fe(NO3)3(aq)

16

What is Calcium used for?

Calcium hydroxide [aka slaked lime, aka Ca(OH)2] is used in agriculture to neutralise acid soils

17

what is Magnesium used for? (with water)

Magnesium hydroxide [Mg(OH)2] is used in some indigestion tablets as an antacid- substance that neutralises excess stomach acid

18

what is the ionic equation for neutralisation?

H+ (aq) + OH- (aq) --> H2O (l)

19

what is Barium used for?

-barium reacts with sulphate to produce barium sulphate
-this chemical is used in barium meals
-Barium sulphate is opaque to x-rays so it allows soft tissues to come up on the x-ray picture
-the patient swallows the barium meal, the barium sulphate coats the tissues, making them show up on the x-rays showing the structure of the organ
-helps to diagnose probs with the oesophagus, stomach or intestines

20

what else can magnesium be used for? state the equation

-magnesium can be used in the extraction of Titanium from its ore
-the main titanium ore (TiO2) is converted to titanium chloride (TiCl4) by heating it with carbon in a stream of chlorine gas
-the titanium is then purified by fractional distillation, before being reduced by magnesium in a furnace pf almost 1000 degrees

-TiCl4(g) + 2Mg(l) --> Ti(s) + 2MgCl2(l)

21

what is calcium oxide and calcium carbonate used for?

-sulphur dioxide (a pollutant) is produced when fossil fuels are burnt
-the acidic sulphur dioxide can be removed from flue gases in a process called wet scrubbing
-powdered calcium oxide (lime, CaO) and calcium carbonate (CaCO3) can both be used for this
-a slurry is made by mixing the CaO or calcium carbonate with water
-it's then sprayed onto the flue gases
-the slurry reacts with the sulphur dioxide to produce Calcium Sulphate

22

give the equation for a slurry made up of calcium oxide reacting with sulphur dioxide

CaO(s) + 2H2O(l) + SO2(g) --> CaSO3(s) + 2H2O(l)

23

give the equation for a slurry made up of calcium carbonate reacting with sulphur dioxide

CaCO3(s) + 2H2O(l) + SO2(g) --> CaSO3(s) + 2H2O(l) + CO2(g)