Experiment 2: The Alkaline Earths And Halogens

Question 1

As you have already seen, the elements in a given _____ in the periodic table are referred too as a _____, or a _____.

Answer 1

Column-Group-Family

Question 2

We will be focusing on the reactivities of the following two groups in this experiment:

Answer 2

Alkaline Earth Metals-Halogens

Question 3

Which group are the earth metals and which group are the Alkaline Earth Metals?

Answer 3

1A are the Earth Metals and 2A are the Alkaline Earth Metals

Question 4

Between the alkali metals and the alkaline earth metals, which group is more reactive?

Answer 4

Alkali Metals

Question 5

What properties do the Alkaline Earth Metals have?

Answer 5

They are highly electro positive and constitute the second most reactive group of metals. The alkaline earth metals have a larger nuclear charge than the alkali metals. Because of the larger nuclear charge, each alkaline earth metal has a smaller atomic radius than the alkali metals.

Question 6

The _____ ion is an exceptionally small cation.

Answer 6

Beryllium

Question 7

Why do Alkaline Earth Metals have a higher density, boiling point, melting point, and hardness compared too alkali metals?

Answer 7

Because they are smaller and have two valence electrons instead of one.

Question 8

What is the trend with degree of hardness and atomic number?

Answer 8

With an increasing atomic number (number of protons), the degree of hardness decreases. THEY HAVE AN INVERSE RELATIONSHIP

Question 9

Generally speaking, are Alkali Metals more soluble in water or Alkaline Earth Metals?

Answer 9

The salts of Alkali metals are very soluble in water.

A number of alkaline earth metal compounds are not appreciably water soluble.

Question 10

What is the trend between the solubility of Alkaline Earth Sulfates and Cation Size?

Answer 10

The solubility of Alkaline Earth Sulfates is found to decrease with increasing cation size.

Question 11

BeSO4 is very _____, and BaSO4 is very _____.

Answer 11

Soluble-Insoluble

Question 12

BaSO4 is found to _____ out of solution.

Answer 12

Precipitate

Question 13

All of the Alkaline Earth Metals exist in their compounds and in solutions as _____ cations.

Answer 13

M 2+

Question 14

What will happen if an Alkaline Earth Metal and an anion are mixed in solution (assuming that the resulting compound is insoluble)?

Answer 14

An Alkaline Earth salt will precipitate.

Question 15

Beryllium is _____ and Radium is _____.

Answer 15

Poisonous-Highly Radioactive BP-RR

Question 16

Which group do Halogens occupy?

Answer 16

7

Question 17

_____ exist as diatomic molecules.

Answer 17

Halogens

Question 18

What is a tendency of Halogens?

Answer 18

They tend to gain electrons and form X- anions.

Question 19

Why are Halogens Oxidizing Agents?

Answer 19

Because they tend to oxidize (remove electrons from) other species.

Question 20

How is a Halide written?

Answer 20

Y-

Question 21

What is the reaction when a halogen is mixed with a halide?

Answer 21

X2+ 2Y (-) —-> 2X (-) + Y2

Question 22

Under what conditions will the Halogen and Halide interaction result the way it does?

Answer 22

The reaction will only occur if X2 can remove electrons from Y- . In other words, X2 must be a better oxidizing agent than Y2).

Question 23

What would happen if Y2 was a better oxidizing agent than X2?

Answer 23

The reaction would proceed in the opposite direction, meaning it wouldn’t happen.

Question 24

In the reaction of halogens and halide ions, what is X said to be?

Answer 24

X is said to be reduced.

Question 25

What is the reaction between a halogen molecule and a halide ion commonly called? Why?

Answer 25

Because the overall reaction consists of an oxidation reaction occurring simultaneously with a red deduction reaction, it is called a redox reaction.

Question 26

How will we be able to determine solubility trend for the Alkaline Earth Group?

Answer 26

By performing simple solubility tests with several Alkaline Earth Metals.

Question 27

How will we be able to determine the relative oxidizing strengths of several halogens/

Answer 27

By mixing solutions of halogens and halide ions. We can also use the characteristic colors of halogens to inform us of chemical reactions.

Question 28

_____ have no color in water solution and are not soluble in organic solvents, such as hexane.

Answer 28

Halide Ions

Question 29

What is the color of Bromine in Hexane?

Answer 29

Orange.

Question 30

Define Oxidation

Answer 30

Loss of Electrons. OL

Question 31

Define Reduction

Answer 31

Gain of electrons. RG

Question 32

Define Oxidizing Agent

Answer 32

Causes oxidation by the removal of electrons from other species. In the process, the oxidizing agent is reduced.

Question 33

True or False: The strongest oxidizing agent is best at causing other substances to be oxidized. Conversely, the strongest oxidizing agent is the most easily reduced species.

Answer 33

TRUE

Question 34

Which elements will NOT be used in this experiment?

Answer 34

Beryllium-Radium-Astatine-Fluorine. BRAF

Question 35

Which ions in this experiment are spectator ions?

Answer 35

NO3- ; H+ ; Na+ ; NH4+ ; K+. NH-NNK

Question 36

If the solution forms a precipitate with your unknown, what can you infer?

Answer 36

If the solution forms a precipitate, you know for sure what the unknown cation is. If it doesn’t, you know one cation that the unknown is not.

Question 37

What will the unknown contain?

Answer 37

One Halide Ion and One Alkaline Earth Cation

Question 38

What is the trend for atomic radius?

Answer 38

Increasing from right to left and top to bottom.

Question 39

How do you tell if something is better oxidizing agent than something else?

Answer 39

For example, let’s say we have X and Y (both are oxidizing agents). In solution, X is red and Y is green. Once they turn into their ion form in the reactions they undergo, they are colorless. When a solution of X is mixed with one containing Y-, the solution goes from red to green. Since there was a color change from red to green, X would be a better oxidizing agent.