Group 2

Question 1

Outline the trend in Gp2 for atomic radius

Answer 1

Increases down the group (more shell and shield)

Question 2

Outline the trend in ionisation energy in gp2

Answer 2

Decrease down the group
More shells and shielding = less attraction -> less IE

Question 3

Outline the trend in melting points

Answer 3

Decrease down the group
Hi ionic radius so less e- attraction of ions and sea of e- so weak metal bonds

Question 4

Rank the gp2 hydroxides for solubility (descending order)

Answer 4

Ba(OH)2
Sr(OH)2
Ca(OH)2
Mg(OH)2

Question 5

Rank the Gp2 sulfates solubility (in descending order)

Answer 5

MgSO4
CaSO4
SrSO4
BaSO4

Question 6

Outline the reaction of Mg with steam & outline why MgO forms & not Mg(OH)2

Answer 6

Mg(s) + H2O (g) -> MgO(s) + H2(g)
Mg(OH)2 decomposes in heat

Question 7

Outline the 3 reaction observations & their reasons

Answer 7

1. Gas produced burns = H2 flammable
2. Mg burns bright = Exothermic
3. White (s) produced = MgO

Question 8

Outline the reaction of Ca with H2O & conditions

Answer 8

Ca(s) +2H2O (l) -> Ca(OH)2 (s) +H2 (g)
H2O is cold

Question 9

Outline the 3 observations and reasons for Ca and H2O

Answer 9

1. Gas pops with lit splint= Flammable H2O
2. Flask hot = Exothermic
3. White ppt = Ca(OH)2 not that soluble
4. pH 12 = Alkaline

Question 10

Outline the reaction of Sr and H2O

Answer 10

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

Question 11

Outline the observations for SO4^2- ions

Answer 11

White ppt - BaSO4
H2O & CO2 as bi-productsO

Question 12

Outline the reagent for SO4^2- test and give a reason as to why

Answer 12

Acidified BaCl2 - to react with CO3^2- ions to prevent reaction

Question 13

Outline the observations for Ba^2+ ions

Answer 13

White ppt - BaSO4
H2O & CO2 as bi products

Question 14

Outline the reagent for Ba2+ test

Answer 14

Na2SO4 solution

Question 15

Outline the observations for the test for OH- ions

Answer 15

White ppt Mg(OH)2

Question 16

Outline the reagent for the OH^- test

Answer 16

MgCl2

Question 17

Outline the observation for the Mg2+ ions test

Answer 17

White ppt Mg(OH)2

Question 18

Outline the reagent for the Mg2+ test

Answer 18

NaOH (aq)

Question 19

Outline the observation for the Cl- ion test

Answer 19

White ppt (AgCl2)

Question 20

Outline the reagent for the Cl- ion test and outline why

Answer 20

AgNO3 (acidified) = acid HNO3 to prevent CO3^2- &/or OH- reactingO

Question 21

Outline the observation of the CO3^2- test

Answer 21

Effervescence (bubble thru limewater = milky)

Question 22

Outline the reagent for the CO3^2- test and outline why

Answer 22

HNO3 - all nitrates are soluble

Question 23

Outline the use of Mg(OH)2 in medicine

Answer 23

Antacid - neutralises excess stomach acid

Question 24

Outline the use of Ca(OH)2 in agriculture

Answer 24

Reduces soil acidity & gives Ca2+ ions for growth

Question 25

Outline the use of CaO/CaCO3 to remove SO2 frrom flue gas

Answer 25

Prevents acid rain
1. CaO(s) + SO2(g) -> CaSO3(s)
2. CaCO3(s) + SO2 -> CaSO3(s) + CO2(g)

Question 26

Outline the use of BaSO4 in Medicine

Answer 26

‘Ba meal’ outline gut as x-rays can’t pass (toxic but insoluble so :) )

Question 27

Outline the reaction of Mg for Ti extraction from TiCl4 (Symbol & half)

Answer 27

TiCl4 + 2Mg -> 2MgCl2 + Ti
Mg -> Mg2+ + 2e-
(Mg oxidised & more reactive than Ti)

Question 28

Outline how TiCl4 is formed for extraction

Answer 28

TiO2 + 2C + 2Cl2 -> TiCl4 + 2CO