9.1- THE PHYSICAL AND CHEMICAL PROPERTIES OF GROUP 2

Question 1

What are elements in Group 2 sometimes called?

Answer 1

alkaline earth metals

Question 2

Why are elements in the Group 2 sometimes called alkaline earth metals?

Answer 2

as their oxides + hydroxides are alkaline

Question 3

What block elements are group 2 elements?

Answer 3

s-block elements

Question 4

What is the reactivity of group 2 in comparison to group 1?

Answer 4

group 2 less reactive

beryllium not typical of group

Question 5

What happens to metallic radius going down group 2?

Answer 5

metallic radius increases

Question 6

What happens to density going down group 2?

Answer 6

density increases

Question 7

What happens to first + seconds IEs going down group 2?

Answer 7

first + seconds IEs decreases going down group 2

Question 8

How many electrons do the group 2 elements have in their outer s-orbital?

Answer 8

2 electrons

Question 9

Why does the metallic radii increase going down group 2?

Answer 9

as each element has an extra filled main level of electrons compared with one above it

Question 10

What sort of melting points do group 2 elements have?

Answer 10

high melting pt

Question 11

What structure do group 2 elements have?

Answer 11

giant metallic structure

Question 12

What happens to the electrons in the ‘sea’ of delocalised electrons as you go down group 2?

Answer 12

‘sea’ of delocalised electrons further away from positive nuclei

Question 13

As the ‘sea’ of delocalised electrons further away from positive nuclei going down group 2, what happens to strength of metallic bonds and so what happens to melting pt?

Answer 13

strength of metallic bonds decreases going down group so melting pt decreases slightly going down group starting with calcium

Question 14

What element of group 2 not fit the melting pt trend?

Answer 14

magnesium

Question 15

In all their reaction, what do the atoms of elements in group 2 lose?

Answer 15

lose their 2 outer electrons to form ions with two positive charges

Question 16

Why does first + second IE decrease going down group 2?

Answer 16

takes less energy to remove electrons as they become further away from positive nucleus
nucleus more effectively shielded by more inner shells of electrons

Question 17

What is oxidation?

Answer 17

loss of electrons

Question 18

What happens to group 2 metals in all their reactions? oxidised or reduced

Answer 18

they’re oxidised

Question 19

What happens to the oxidation state when group 2 elements react?

Answer 19

go from oxidation state 0 to oxidation state +2

Question 20

When group 2 metals react with water, what is the trend?

Answer 20

metals get more reactive going down group

Question 21

What type of reaction is group 2 element reacting with water?

Answer 21

redox reaction

Question 22

What is the basic equation for the reaction between a group 2 element and water?

Answer 22

M(s) + 2H20(l) -> M(OH)2 (aq) + H2(g)

Question 23

What is magnesium hydroxide?

Answer 23

milk of magnesia

Question 24

What is magnesium hydroxide used in?

Answer 24

indigestion remedies to neutralise excess stomach acid which causes heartburn, indigestion + wind

Question 25

How quickly does magnesium react with cold water?

Answer 25

very slowly

Question 26

How quickly does magnesium react with steam?

Answer 26

quickly

Question 27

What does magnesium reacting with cold water/ steam produce?

Answer 27

alkaline oxide + hydrogen Mg(s) + H20 (g) -> MgO(s) + H2(g)

Question 28

How does calcium reacting with water compare to magnesium reacting with water?

Answer 28

reacts in same way but more vigorously, even with cold water

Question 29

Which elements of group 2 react more vigorously with water than magnesium + calcium?

Answer 29

strontium + barium

Question 30

What is calcium hydroxide sometimes called?

Answer 30

slaked lime

Question 31

What is calcium hydroxide used for?

Answer 31

used to treat acidic soil

Question 32

What is the trend in solubilities of the hydroxides going down group 2?

Answer 32

going down group they become more soluble

Question 33

What is the colour of all the hydroxides in group 2?

Answer 33

hydroxides all white solids

Question 34

What is the solubility of magnesium hydroxide like?

Answer 34

almost insoluble

Question 35

How soluble is calcium hydroxide Ca(OH)2?

Answer 35

sparingly soluble

Question 36

What is calcium hydroxide as a solution?

Answer 36

lime water

Question 37

What is the solubility of strontium hydroxide Sr(OH)2 like in comparison to calcium hydroxide?

Answer 37

it's more soluble

Question 38

What does barium hydroxide Ba(OH)2 dissolve to produce?

Answer 38

strongly alkaline solution

Question 39

Equation for barium hydroxide dissolving to produce strongly alkaline solution?

Answer 39

Ba(OH)2(s) + aq -> Ba2+(aq) + 2OH-(aq)

Question 40

What is the solubility trend in sulfates going down group 2?

Answer 40

they become less soluble going down group

Question 41

What is the solubility of barium sulphate like?

Answer 41

virtually insoluble

Question 42

What does it mean as barium sulphate is virtually insoluble?

Answer 42

means it can be taken by mouth as barium meal to outline gut in medical X-rays

Question 43

What is the heavy barium atom very good at?

Answer 43

absorbing X-rays

Question 44

What test is the insolubility of barium sulphate used in?

Answer 44

simple test for sulphate ions in solution

Question 45

Simple test for sulphate ions in solution using barium sulphate?

Answer 45

solution first acidified with nitric or hydrochloric acid then barium chloride solution added to solution under test + if sulphate present white precipitate of barium sulphate formed

Question 46

Equation for simple test for sulphate ions in solution using barium sulphate?

Answer 46

Ba2+(aq) + SO4 2-(aq) -> BaSo4(s)

Question 47

What does the addition of acid in the simple test for sulphate ions in solution do?

Answer 47

removes carbonate ions as carbon dioxide