P Block Flashcards
What is the electronic configuration of Group 15 elements?
nsnp
The s orbital is completely filled and p orbitals are half-filled, contributing to their stability.
What trend is observed in covalent and ionic radii down Group 15?
Increase in size
A considerable increase in covalent radius from N to P, while only a small increase is observed from As to Bi due to filled d and/or f orbitals.
How does ionisation enthalpy change down Group 15?
Decreases
This decrease is attributed to the gradual increase in atomic size.
Why is the ionisation enthalpy of Group 15 elements greater than that of Group 14 elements?
Extra stable half-filled p orbitals and smaller size
The extra stability of half-filled p orbitals contributes to higher ionisation enthalpy compared to Group 14.
What is the order of successive ionisation enthalpies for Group 15 elements?
AH1 < AH2 < AH3
This order reflects the increasing difficulty of removing additional electrons.
What are some common minerals containing arsenic, antimony, and bismuth?
Sulphide minerals
These elements are primarily found in sulphide mineral forms.
What is the atomic number of Phosphorus?
15
Phosphorus is an essential constituent of animal and plant matter.
What are phosphoproteins and where are they commonly found?
Present in milk and eggs
Phosphorus is a key component of these proteins.
What is the atomic mass of Nitrogen?
14.01 g/mol
This value represents the mass of one mole of nitrogen atoms.
Fill in the blank: The covalent radius of Phosphorus is ______ pm.
110 pm
What is the boiling point of Arsenic?
888 K
This value indicates the temperature at which arsenic transitions from liquid to gas.
True or False: The covalent radius of Bismuth is larger than that of Arsenic.
True
Covalent radius generally increases down the group.
What is the melting point of Antimony?
631 K
This is the temperature at which antimony changes from solid to liquid.
What is the density of Phosphorus at 298 K?
1.823 g/cm³
Density values give insight into the mass per unit volume of the element.
What is the ionisation enthalpy of Nitrogen?
1402 kJ/mol
This is the energy required to remove an electron from a mole of nitrogen atoms.
What is the trend of electronegativity down the group?
Electronegativity value generally decreases down the group with increasing atomic size.
Amongst the heavier elements, the difference is not that pronounced.
What are the physical states of the elements in this group?
All elements are polyatomic; dinitrogen is a diatomic gas while all others are solids.
Metallic character increases down the group.
What are the classifications of elements in this group?
Nitrogen and phosphorus are non-metals, arsenic and antimony are metalloids, and bismuth is a metal.
This is due to decrease in ionisation enthalpy and increase in atomic size.
How do boiling and melting points change in this group?
Boiling points generally increase from top to bottom; melting point increases up to arsenic and then decreases up to bismuth.
Except nitrogen, all elements show allotropy.
What are the common oxidation states of these elements?
-3, +3, and +5.
The tendency to exhibit -3 oxidation state decreases down the group.
What happens to the stability of the +5 oxidation state down the group?
The stability of the +5 oxidation state decreases down the group.
The only well-characterised Bi(V) compound is BiF5.
What oxidation states does nitrogen exhibit when reacting with oxygen?
+1, +2, and +4.
All oxidation states from +1 to +4 tend to disproportionate in acid solution.
What is the maximum covalency of nitrogen?
4.
This is because only four (one s and three p) orbitals are available for bonding.
How do the heavier elements differ in terms of covalency?
Heavier elements have vacant d orbitals which can be used for bonding, expanding their covalence.
Example: PF5.
What are the anomalous properties of nitrogen?
Nitrogen differs due to its small size, high electronegativity, high ionisation enthalpy, and non-availability of d orbitals.
Nitrogen can form p-p multiple bonds with itself and small, electronegative elements.
What type of bond does nitrogen form?
A triple bond (one s and two p) between two nitrogen atoms.
This results in a very high bond enthalpy of 941.4 kJ/mol.
What type of bonds do phosphorus, arsenic, and antimony form?
Single bonds as P-P, As-As, and Sb-Sb.
Bismuth forms metallic bonds in its elemental state.
Why is the single N-N bond weaker than the single P-P bond?
Due to high interelectronic repulsion of non-bonding electrons caused by small bond length.
This results in weaker catenation tendency in nitrogen.
