AS - group 2

Question 1

Do ionisation energies increase or decrease going down and why?

Answer 1

-decreases
-more shielding
-less attraction
-distance between electron and nucleus decreases

Question 2

do melting points increase or decrease and why?

Answer 2

-decrease
-distance between delocalised electrons and nucleus increase
-ions are bigger
-less attraction

Question 3

does reactivity increase or decrease?

Answer 3

-increases
-weaker attraction between nucleus and outer e-
-less energy required to remove e-

Question 4

what are their reactivities with water?

Answer 4

they get more reactive going down the group

Question 5

what ate the products when reacted with water and whats the equation?

Answer 5

-metal hydroxide and hydrogen
M(s) + 2H2O (l) > M(OH)2 (aq) + H2 (g)

Question 6

which element reacts with steam and what are the products and equation?

Answer 6

-Mg
-Magnesium oxide and hydrogen
Mg(s) + H2O(g) > MgO(s) + H2 (g)

Question 7

what are observations when reacted with water?

Answer 7

-fizzing
-metal dissolving
-solution heating
-calcium > white ppt

Question 8

what happens to their hydroxide solubility?

Answer 8

more soluble down the group

Question 9

what is the ionic equation for Mg(OH)2?
is it soluble?
what is it used for and equation

Answer 9

Mg2+ + 2OH- > Mg(OH)2
almost insoluble
used to neutralise excess stomach acid and treat constipation
Mg(OH)2 + 2HCl > MgCl2 + H2O

Question 10

what is the solubility of Ca(OH)2?
what is it used for and equation

Answer 10

partially soluble - white ppt
agriculture to neutralise acidic soils
aqueous solution = limewater to test for CO2
Ca(OH)2 (aq) + CO2 (g) > CaCO3 (s) + H2O (l)

Question 11

what does Ba(OH)2 dissolve to produce and equation

Answer 11

strongly alkaline solution
Ba(OH)2 (s) + aq > Ba2+ (aq) + 2OH-(aq)

Question 12

describe the sulfate solubility trend

Answer 12

becomes less soluble

Question 13

what is barium sulfate used for?

Answer 13

-barium meal
-absorbs x-rays
-not absorbed into blood

Question 14

describe the test for sulfate ions and ionic equation

Answer 14

-acidified with nitric acid
-barium chloride is added
-positive > white ppt of barium sulfate
Ba2+ (aq) + SO42-(aq) > BaSO4(s)

Question 15

why is the solution acidifed with nitric acid when testing for sulfate ions?

Answer 15

-removes any carbonate ions as CO2
-barium carbonate is also a white insoluble solid - false positive

Question 16

how is titanium extracted?

Answer 16

-titanium oxide reacted with chlorine and coke
forms titanium chloride and carbon monoxide
TiO2 +2Cl2 + 2C > TiCl4 + 2CO
Then reduced by reacting with magnesium
TiCl4 (l) + 2Mg (s) > 2MgCl2 (s) + 2Ti (s)