Group 1 and 2 reactions

Question 1

How does reactivity change down the groups?

Answer 1

Increases down because to react, they lose outer shell electrons
Due to reasons of IE decreasing down, less energy is needed to lose electrons so increases down

Question 2

How does the ionisation energy change down the group?

Answer 2

Decreases because the number of electrons increase thus fill up more shells. This causes more electron electron repulsion and increases atomic radii which decreases nuclear force

Question 3

How does the melting point change as you go down the group?

Answer 3

Decreases because of the increase in ionic radii causing the delocalised electrons to experience less nuclear attraction

Question 4

Group 2 + water produces?

Answer 4

A metal hydroxide and hydrogen

Question 5

Exception to group 2 + water reaction

Answer 5

Beryllium = doesn’t react but can react with steam only
Magnesium = can react with steam and water (but with water very slightly)

Question 6

What does magnesium + steam produce?

Answer 6

Magnesium oxide and hydrogen
Vigorously

Question 7

What does magnesium + water produce?

Answer 7

Magnesium hydroxide + hydrogen
Quite slowly
Weakly alkaline solution because Mg(OH)2 is not that soluble in water

Question 8

How does calcium + water react?

Answer 8

Moderately, produces calcium hydroxide and effervescence (hydrogen)
Slightly alkaline solution because is slightly soluble in water

Question 9

How does strontium and water react?

Answer 9

Reacts rapidly, produces strontium hydroxide and a lot of effervescence (hydrogen)
Alkaline solution because quite soluble in water

Question 10

How does barium react with water?

Answer 10

Barium hydroxide and hydrogen is produced (effervescence) which reacts very vigorously
Alkaline solution because is soluble in water

Question 11

What does group 2 and oxygen react to form?

Answer 11

Group 2 metal oxide
(Solid white)

Question 12

When group 2 reacts with oxygen, what is reduced?

Answer 12

The oxygen because it gained 2 electrons

Question 13

When group 2 reacts with oxygen, what is oxidised?

Answer 13

The metal because it loses 2 electrons to form a positive metal ion in the metal oxide compound

Question 14

Does beryllium oxide exist?

Answer 14

Yes

Question 15

Are oxides bases?

Answer 15

Yes and because of the fact that solubility increases going down the group, they are of increasing alkaline strength going down

Question 16

Does beryllium hydroxide exist?

Answer 16

No beryllium does not react with water

Question 17

Does beryllium oxide dissolve in water?

Answer 17

No so does not act as a base

Question 18

Why does the pH of dissolved metal hydroxide/ oxides increase going down the group?

Answer 18

Because the solubility increases going down the group
And so concentration of OH- ions releasing increases = alkaline solution

Question 19

Metal oxide + water

Answer 19

Produces just the metal hydroxide corresponding and NO effervescence

Question 20

Metal hydroxide + water

Answer 20

From the solid metal hydroxide precipitate to aqueous metal hydroxide

Question 21

What is milk of magnesia?

Answer 21

Magnesium hydroxide

Question 22

Why is milk of magnesia milky?

Answer 22

Because it’s very insoluble do forms white precipitate

Question 23

Metal oxide (basic pH) with dilute acid reaction

Answer 23

Produces aqueous metal salt eg calcium chloride and water

Question 24

Metal hydroxide (basic pH) with dilute acid reaction

Answer 24

Produces aqueous metal salt and water

Question 25

Solubility trend of metal sulfates?

Answer 25

The solubility decreases down the group unlike hydroxides so beryllium sulfate most soluble

Question 26

What does the solubility of metal compounds depend upon?

Answer 26

The charge of the anion
OH- has 1- charge so solubility increases down the group
SO4 2- has 2- charge so solubility decreases down the group

Question 27

Thermal decomposition

Answer 27

When a substance breaks down on heating

Question 28

How can we test for barium ions? (Other than flame test)

Answer 28

Add compound that might have barium into sulfate solution
White propitiate forming indicates barium ions present because it is the most insoluble in sulfate solution

Question 29

How to test for mg ions other than flame test

Answer 29

React compound with water to form magnesium hydroxide which is insoluble in water so white precipitate would be formed

Question 30

Barium sulfate uses

Answer 30

A barium meal to coat oesophagus so when X-rays are absorbed, you can see the digesting tract as if it were bone to check for problems = photopaque
Insolubility allows barium sulfate to be suspended and picked up on

Question 31

Magnesium hydroxide uses

Answer 31

Helps with indigestion (milk of magnesia precipitate)
Neutralises acid stomach

Question 32

Calcium hydroxide uses

Answer 32

Used as slaked lime to neutralise pH of soil (which was acidic) for specific crop growth

Question 33

Titanium extraction

Answer 33

Titanium exists as titanium oxide then titanium chloride
Where magnesium reduces titanium to produce titanium

Question 34

Removal of SO2

Answer 34

Using calcium carbonate to form calcium sulphite from sulfur dioxide

Question 35

Why does the reaction with magnesium and water slow down?

Answer 35

Magnesium is coated with a layer of magnesium hydroxide so reaction stops after a while

Question 36

As the solubility of hydroxides increase down the group what happens?

Answer 36

Less solid precipitate remains and more dissolves thus more solution formed

Question 37

What slows down the reaction of sulfuric acid and metal (barium, strontium etc)

Answer 37

Barium/strontium sulfates which coats the metal and therefore stops reaction

Question 38

Reaction of metals with dilute nitric acid

Answer 38

Produces hydrogen and a metal nitrate
Hydrogen in acid reduced to gas
Metal oxides oxidised to ions

Question 39

Reaction of metals with more concentrated nitric acid

Answer 39

Forms a metal nitrate
But Nitrate ions can be reduced (gain electrons) to nitrogen monoxide or nitrogen dioxide (these produced as well)
And water (NOT HYDROGEN)

Question 40

Magnesium in water observations

Answer 40

Slight bubbles produced on the surface
Floats on surface of water