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Flashcards in Group 2 Deck (14)
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1
Q

What are group 2 elements also known as?

A

Alkaline earth metals

2
Q

What is the redox half equation for how group 2 metals react?

A

M-> M2+ + 2e-

3
Q

What colours are group 2 compounds and solutions?

A

Compounds- White

Solutions- colourless

4
Q

What are the properties of group 2 metals?

A

Light low densities

High melting points

5
Q

What is the trend in reactivity down group 2 and why?

A

Increases in reactivity-
Strength of metallic bond decreases as more shielding and outer electron is further away so it is easier to loose the 2 electrons

6
Q

What happens to the group 2 elements oxidation number in a redox reaction and what does this mean?

A

Oxidation number increases so is oxidised and acts as the reducing agent

7
Q

How does a group 2 element react with oxygen-
What is formed?
And give the half equations and oxidation numbers-

A

2M+O2 -> 2MO
OXIDES ARE FORMED

2M-> M2+ + 2e-
O2 + 4e- -> 2O2-

M(0) -> M(+2) oxidised
O2(0) -> O2 (-2) reduced

8
Q

How does Mg react with water-

What is formed? And why is this different to other group 2 elements?

A

Mg + H2O -> MgO + H2

Mg is the least reactive so only reacts with steam rapidly

9
Q

How does a group 2 element react with water-
What is formed?
And give the half equations and oxidation numbers-
How does the solubility of the product change?

A

M + 2H2O -> M(OH)2 +H2
ALKALINE METAL HYDROXIDES - increased solubility as you go down group

M-> M2+ + 2e-
2H+ + 2e- -> H2

M(0) -> M(+2) oxidised
H(+1) -> H(0) reduced

10
Q

How does a group 2 element react with a dilute acid-
What is formed?
And give the half equations and oxidation numbers-

A

M+ H2SO4 -> MSO4 + H2
M+ 2HCl -> MCl2+ H2
M+ 2HNO3 -> M(NO3)2 + H2

M-> M2+ + 2e-
2H+ + 2e- -> H2

M(O) -> M(2+) oxidised
H(+1) -> M(0) reduced

11
Q

What is the reaction of a group 2 oxide with water?

A

MO+ H2O -> M(OH)2

12
Q

What trends do you see as you go down the group 2 hydroxides?

A

Increasing solubility
Increase in pH (OH- ions)
Increase in alkalinity

13
Q

What is Ca(OH)2 used for?

A

Neutralise acidic soils

14
Q

What group 2 compounds neutralise stomach acid?

A

Mg(OH)2

CaCO3