Group 13 Flashcards
(153 cards)
What is the general trend in the chemistry of p-block elements?
Variation in properties due to d and f electrons in heavier elements
This influences their physical and chemical properties.
What is the valence shell electronic configuration of p-block elements?
ns2np1-6 (except for He)
The number of p orbitals is three, allowing a maximum of six electrons.
How does the maximum oxidation state of a p-block element relate to its valence electrons?
Maximum oxidation state equals the total number of valence electrons
This includes the sum of s- and p-electrons.
What is the trend in oxidation states as you move across the p-block?
Oxidation states generally increase towards the right
Other oxidation states may differ by units of two.
What is the inert pair effect?
The stability of oxidation states two units less than the group oxidation state
It is observed in heavier elements of the boron, carbon, and nitrogen families.
Which elements are classified as non-metals and metalloids in the p-block?
Non-metals: Boron, Carbon, Nitrogen, Oxygen, Fluorine; Metalloids: elements between non-metals and metals
Non-metals decrease in character down the group.
What characterizes the compounds formed by highly reactive non-metals with highly reactive metals?
Generally ionic due to large differences in electronegativities
Non-metals readily form anions.
How does the first member of the p-block differ from heavier members?
Size and properties dependent on size, and lack of d-orbitals in second period elements
Heavier elements can expand their covalence using d-orbitals.
What is the significance of d-orbitals in heavier p-block elements?
Influences the ability to form π bonds and coordination numbers
Heavier elements can form multiple bonds involving d-orbitals.
What are the first members of each group in the p-block?
Boron, Carbon, Nitrogen, Oxygen, Fluorine, Helium
These elements lead their respective groups.
What are the important minerals of aluminium?
- Bauxite (Al2O3·2H2O)
- Cryolite (Na3AlF6)
Aluminium is the most abundant metal in the Earth’s crust.
What is the atomic radius trend in Group 13 elements?
Atomic radius increases down the group, with exceptions like Ga < Al
Ga has poor screening effect from d-electrons.
What causes the discontinuity in ionization enthalpy values in Group 13?
Inability of d- and f-electrons to screen increased nuclear charge
This leads to observed discontinuities between Al and Ga, In and Tl.
How does electronegativity change down Group 13?
Decreases from B to Al, then increases marginally
This is due to discrepancies in atomic size.
What are the physical properties of boron?
Non-metallic, extremely hard, black solid, high melting point
Exists in many allotropic forms.
What is the predominant oxidation state of thallium?
+1 oxidation state
The +3 oxidation state is highly oxidizing.
What is the nature of compounds formed in the +3 oxidation state of Group 13 elements?
Electron deficient molecules that behave as Lewis acids
They tend to accept electron pairs to achieve stable configuration.
What characterizes the chemical reactivity trend in Group 13?
Aluminium forms Al3+ ions; heavier elements show +1 and +3 states with increasing stability of +1
The inert pair effect restricts participation in bonding.
What oxidation states are observed in p-block elements?
+1 and +3 oxidation states
How do the +1 and +3 oxidation states compare in terms of ionic character?
Compounds in +1 oxidation state are more ionic than those in +3 oxidation state
What is the electron configuration of trivalent compounds of p-block elements like boron in BF3?
Only six electrons around the central atom
What behavior do electron deficient molecules exhibit in terms of Lewis acids?
They tend to accept a pair of electrons
How does the tendency to behave as a Lewis acid change down the group of p-block elements?
It decreases with the increase in size down the group
What happens when BCl3 interacts with ammonia?
Forms BCl3·NH3
