Group 2

Question 1

What is metallic radius

Answer 1

Half the distance between nuclei in a giant metallic lattice

Question 2

Describe and explain the trend in IE down group 2

Answer 2

IE decreases
Nuclear charge increase outweighed by sheilding effect
And distance from valence shell increasing

Question 3

Describe the trend in reactivity of group 2

Answer 3

Reactivity increases

Ability to lose e- increases

Question 4

Why are cations of group 2 smaller in radius than their atoms

Answer 4

Cations have one less shell

Less electrons less repulsion

Question 5

Describe the trend in reducing power down group 2

Answer 5

Increases

Question 6

Describe and explain the trend in melting points down group 1 and 2

Answer 6

Decreases
Size of atom increases
Decrease in metallic bond strength

Question 7

Write an equation for the reaction of group 2 metals with H2O

Answer 7

X + H2O—-> X(OH)2 + H2

Question 8

Describe observations of reaction of group 2 metals with water down the group

Answer 8

Reaction vigour increases down group-effervescence of H2 gas increases

Solubility of hydroxides formed increases thus pH increases more alkaline solution formed

Question 9

Describe and explain the trend in solubilities of sulfates down group 2

Answer 9

Solubility decreases 
BeSO4 (aq)
MgSO4 (aq)
CaSO4 (s)
SrSO4(s)
BaSO4 (s) 

Radius of cation increases charge density decreases
Lattice energy decreases
Enthalpy of hydration decreases
Decrease in enthalpy of hydration is greater
Thus enthalpy of solution becomes more endothermic

Question 10

Describe and explain the trend in solubility of group 2 hydroxides and oxides

Answer 10

Increases down group
Be(OH)2 / Mg(OH)2 (s) insoluble
Ca(OH)2 (aq) partially soluble
Sr(OH)2/Ba(OH)2 (aq) very soluble

Both L.E and ΔHhyd decrease
Decrease in LE is greater than hydration
Enthalpy of solution becomes more exothermic

Question 11

Write equation for reaction of group 2 metals with oxygen

Answer 11

X + 1/2O2 —–> XO

Question 12

Observations when Be reacts with oxygen

Answer 12

Silver grey solid dissappears
White solid forms
Bright White flame

Question 13

Observations when Mg reacts with oxygen

Answer 13

Silvery grey solid dissapears
White solid formed
Burns in white flame

Question 14

Observations when Ca reacts with oxygen

Answer 14

Silvery grey solid dissappears
White solid formed
Burns in a brick red flame

Question 15

Observations when Sr reacts with oxygen

Answer 15

Silvery grey solid dissappears
White solid appears
Burns in scarlett/crimson red flame

Question 16

Observations when Ba reacts with oxygen

Answer 16

Silvery grey solid dissappears
White solid appears
Burns in apple green flame

Question 17

Write equation for reaction of oxides and hydroxides with dilute acid

Answer 17

Basic oxide/ hydroxide + dilute acid—> salt + water

Question 18

Write equation for reaction of a group 2 metal with dilute acid

Answer 18

Metal + dilute acid —-> salt + H2

Question 19

Write equation for reaction of group 2 carbonates with dilute acid

Answer 19

Carbonate + dilute acid —-> salt + CO2 + H2O

CO2 turns limewater milky

Question 20

Reaction of group 2 carbonates with water

Answer 20

INSOLUBLE

Question 21

What carbonates are soluble in water

Answer 21

Group 1 and ammonium carbonates are soluble

Question 22

Reaction of BeO with water

Answer 22

No reaction insoluble

Question 23

Reaction of MgO with water

Answer 23

MgO+ H2O—> Mg(OH)2 (aq) very slightly soluble
CaO + H2O —> Ca(OH)2 (aq)
SrO + H2O—-> Sr(OH)2 (aq)
BaO + H2O —–> Ba(OH)2 (aq)

Question 24

Write equation for thermal decomposition of group 2 carbonates

Answer 24

XCO3 (s)—-> XO(s) + CO2 (g)

Question 25

Describe and explain trend in thernal stabilities of group 2 carbonates and nitrates

Answer 25

Thermal stability increases Down the group charge density of cation decreases Ability of cation to polarize anion decreases Bonds get less polarized More heat required down the group (thermal decomposition becomes more endothermic)

Question 26

Write equation for thermal decomposition of nitrates

Answer 26

X(NO3)2 ----> XO (s) + 2NO2(g) + 1/2O2 (g)

Question 27

Observation of decomposition of nitrates

Answer 27

Brown NO2 gas

Question 28

Write equation for thermal.decomposition of group 2 hydroxides

Answer 28

X(OH)2 ----> XO (s) + H2O (g)

Question 29

Uses of MgO

Answer 29

Refractory material in lining of furnaces

Question 30

Uses of Mg(OH)2

Answer 30

Antacid tablets

Question 31

Uses of CaO( quick lime) and Ca(OH)2

Answer 31

Used to treat acidic soils and for flue gas desulfurization | / USED TO RAISE PH

Question 32

Uses of CaCO3 (limestone)

Answer 32

Building material

Question 33

Uses of BaSO4

Answer 33

Ba meal for x rays