group 2

Question 1

trend of atomic radius as we go down group 2

Answer 1

atomic radius increases as extra shells added

Question 2

ionisation energy trend in group 2

Answer 2

1st ionisation energy decreases as we go down group 2- there is more shielding hence weaker attraction between the nucleus and outer electrons, the outer electrons are also further from the nucleus, although increase in protons but shielding effect overrides

Question 3

melting point energy trend in group 2

Answer 3

metallic structures so the size of the metal ion increase but number of delocalised electrons and charge remains same means the distance between positive nuclei and electrons is bigger weakens attractive force

Question 4

what is the exception of mpt trend

Answer 4

magnesium due to structural difference

Question 5

group 2 elements react with water to form …

Answer 5

bases, metal hydroxides

Question 6

reactivity … with water because?

Answer 6

increases
larger atoms and so electron further from nucleus so easier to remove and more reactive

Question 7

what are exceptions to reactions with water

Answer 7

Be no reaction w water
Mg reacts with steam to make MgO and reacts slowly w cold water to form MgOH

Question 8

solubility trend in group 2

Answer 8

group 2 sulfates (-2charge) become less soluble down the group
group 2 hydroxides (-1charge) become more soluble down the group

Question 9

tests for sulfates

Answer 9

using barium chloride
-add HCl to remove carbonates
-add barium chloride
-white ppt will form if present as BaSO4 is insoluble

Question 10

group 2 compounds can be used to … acids. what are some examples

Answer 10

neutralise
acidic soils- CaOH used to neutralise acidic soils
antacids- MgOH used to neutralise excess stomach acid

Question 11

ionic equation for neutralisation

Answer 11

H+ + OH- => H2O

Question 12

what are barium meals

Answer 12

barium sulfate also known as barium meal

Question 13

purpose of barium meal

Answer 13

used to help identify problems with the digestive tract. patient drinks suspension of baso4 coating the lining of soft tissues, patient stands in an x ray machine and x rays are absorbed by barium sulphate and will show up on x ray that wouldn’t normally

Question 14

why can humans ingest barium sulfate

Answer 14

barium compounds are toxic however because various sulfate is insoluble it can’t be absorbed into the blood

Question 15

what is used to extract titanium from its ore

Answer 15

magnesium

Question 16

how is titanium extracted

Answer 16

titanium ore is converted to titatnium chloride by heating with carbon and chloride gas

titanium chloride is passed thought fractional distillation to increase purity

this is reduced using magnesium in a 1000°C furnace

Question 17

titanium properties and what its used for

Answer 17

light weight but strong most commonly used in planes

Question 18

what is used in removal of sulfur dioxide

Answer 18

use calcium carbonate and oxide to remove sulfur dioxide emissions

Question 19

what is wet scrubbing

Answer 19

a method whereby an alkali is used to neutralise sulfur dioxide in flue gases
wet scrubbing involves dissolving calcium carbonate or oxide in water and spraying on acidic sulfur dioxide gas

Question 20

how is sulfur dioxide produced

Answer 20

when fossils fuels burnt it produces this pollutant

Question 21

what can product of wet scrubbing be used for

Answer 21

calcium sulphite can be used for production of plasterboard