Group 2 Flashcards

1
Q

What are group 2 elements also known as?

A

Alkali earth metals.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a metallic radius?

A

Half the distance between the nuclei in a giant metallic lattice.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the trend of metallic radius in group 2 elements?

A

Metallic radius gets larger going down the group. This is because the outer two electrons occupy a new principal quantum shell that is further away from the nucleus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the trend in melting point of group 2 elements?

A

It decreases as you go down the group.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the trend in density as you go down group 2 elements?

A

Density increases as you go down the group until you reach strontium where it increases to 2.6 and barium is 3.5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the oxidation number of group 2 elements?

A

+the metals act as reducing agents. Their atoms donate (give away) electrons and so they are oxidized themselves as they react to form their 2+ ions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the trend in ionisation energy down group 2 elements?

A

Ionisation energy decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the trend in reactivity of group 2 elements as we go down the group?

A

The metals in group 2 get more reactive as we go down the group. It gets easier to remove the pair of outer electrons going down ther group, so although the positive charge on the nucleus increases the greater sheilding effect providedcby the inner shells of electrons and the larger distance of the outer most electrons from the nucleus outweighs the attraction of the higher nuclear charge. Thus the group 2 elements get more reactive going down the group.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How can the trend in group 2 elements reactivity be shown.

A

By looking at reactions of group 2 metals, magnesium to barium with dilute hydrochloric acid, forming a solution of the metal chloride and giving of hydrogen gas. You can see the reactions getting more vigorous descending the group by the increasing rate at which bubbles of hydrogen gas is given off.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the reaction of magnesium with dilute Sulfuric acid?

A

Mg(s)+H2S04 (aq) + H2(g)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the reaction between calcium, strontium or barium and sulfuric acid.

A

Any reaction with calcium, strontium or barium is quickly stopped by the formation of an insoluble sulfate layer on the surface of the metals. For example you can see a slow stream of of hydrogen bubbles fta short time when a pellet (small piece) of calcium metal is dropped into dilute Sulfuric acid.
Ca(s)+H2S04 (aq)=CaSO4(s)+H2(g)
The calcium then gets completely covered by a layer sparingly soluble calcium sulfate and the bubbles stop rising from the metal. Strontium and barium sulfate are even less soluble than calcium sulfate so will quickly stop any reaction with the metals strontium and barium.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the trend in solubility of group 2 elements

A

Get less soluble going down the group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe how to conduct a flame test.

A

We can test for calcium stontium and barium ions in compounds using flame tests. A nichrome wire cleaned with a concentrated hydrochloric acid is dipped into a sample of the salt to be tested and heated in non-luminous bunsen flame.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the flame test result of calcium compounds?

A

Brick red color

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the test result of strontium compound flame test?

A

Scarlet red color

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the test result of barium compounds

A

Apple green color

17
Q

What is the pH of a saturated solution of magnesium hydroxide?

A

PH value of 10.

18
Q

Describe the trend in the pH of group 2 metal oxides with water

A

The solutions formed from the reactions of the group 2 metal oxides with water to get more alkaline going down from the group

19
Q

Describe the trend in group 2 metal oxides solubility going down the group

A

The solutions formed from the of the group 2 metal oxides with water to get more alkaline going down the group

20
Q

Describe the trend in solubility of group 2 hydroxides increases going down group 2

A
21
Q

What color gas is observed when a group 2 nitrate is heated

A

A brown gas is observed when a group 2 nitrate is heated. This is toxic nitrogen dioxide.