Chapter 13: Group 13 Elemenets Flashcards
In reality, aluminum forms a protective layer and does not react with water. [T/F]
-True, this is known as anodizing
Which Statement about Gallium is False?
It is mainly found in the oxidation state +1
Which Statement about Gallium is True?
- It melts on contact with human hands
- it can combine with with aluminum to reduce water
- It can form a good source of hydrogen
Thallium is highly toxic and therefore it is commonly used for rat poisons and insecticides in the United States. [T/F]
- False
- Since 1975, thallium is prohibited from such usage since there is no warning if one digested it.
Which is true about Aluminum Oxide?
-In its crystalline form it is called corundum
What is false about Aluminum Oxide?
- It has poor corrosion resistance
- It is not a very good thermal insulator
- It is not a very reactive metal
Aluminum is amphoteric? [T/F]
-True, aluminum can dissolve in both acids and bases
What is true about Boron?
-It is an important element that we use in our daily lives.
What is false about Boron?
- It has the electron configuration [Ne]2s^2 2p^1
- It is the first metal of Group 13
- It has an atomic number 6.
Which element is the only metalloid in the boron family?
Boron
When beryllium reacts with a halide, which of the following is true?
-It forms a Lewis Acid
When beryllium reacts with a halide, which of the following is false?
- it acts as a Lewis Base
- It forms a covalent bond
- It forms a neural molecule
What is the electron configuration of Thallium?
[Xe]6s^2 6p^1
Which statements are true, and which are false?
1-Thallium is the heaviest element.
2-Boron has the highest melting point
3-Electron potential increases going down the group
4-Thallium has the lowest ionization energy.
- FALSE: 4
- TRUE: 1, 2, 3
Borane occurs as a gaseous substance, and can form B2H6 by two borane molecules combined with each other. Why is borane not a stable compound?
Borane does not follow a complete octet rule since it has six valence electrons, therefore forms diborane.
The most common oxide form of boron, B2O3 or boron trioxide, is obtained by heating boric acid: write a reaction?
2B(OH)3 + heat –> B2O3 + 3H2O
Aluminum occurs amost exclusively in the +3 oxidation state. It rapidly reacts with oxygen in air to give a water-insoluble coating of Al2O3. This oxide layer protects the metal beneath from further corrosion. Write the reaction:
4Al(s) + 3O2(g) –> 2Al2O3
Al2O3, is amphoteric, so write 2 reactions where it acts both as an acid and a base:
Acid:
Al2O3(s) + 6HCl(aq) –> 2AlCl3(aq) + 3H2O(l)
Base:
Al2O3(s) + 2NaOH(aq) + 3H2O(l) –> 2NaAl(OH)4
Thallium is the only element in this group that favors the formation of an oxide instead of a trioxide. Write the reaction and explain why?
4Tl(s) + O2(g) –> 2Tl2O(s), it forms +1 oxidation state because of the inert pair effect.
