Unit 3 Flashcards
(110 cards)
What colour is [Co(H₂O)]²⁺?
Pink
What colour is [CoCl₄]²⁻?
Blue
Which Groups in the periodic table is the P-Block?
Groups 3 - 0 (Inclusive)
What is Octet expansion?
The ability of elements to use available d-Orbitals so that there are more than 8 electrons in the outer shell.
What is a Hypervalent molecule?
One formed by octet expansion.
Why can Nitrogen not expand its octet?
There is no available D-Orbital for it to promote an electron to.
What is an electron deficient atom?
One that does not have a full outer shell of electrons (<8).
What is the inert pair effect?
The reluctance of the S² pair of electrons in the bonding level (outer shell) to be involved in bonding.
What is the trend of the inert pair effect?
The S² pair are less likely to be involved in bonding as you go down the group.
The inert pair effect increases down the group.
Define ‘Amphoteric Character’.
A substance that can act as an acid or a base.
What is the Equation for Aluminium acting as a base?
Al₂O₃ +6HCl –> 2AlCl₃ + 3H₂O
What is the Equation for Aluminium acting as an acid?
Al₂O₃ + 2NaOH + 3H₂O –> 2Na[Al(OH)₄]
What is the Equation for Lead acting as a base?
PbO + 2HNO₃ –>Pb(NO₃)₂ + H₂O
What is the Equation for Lead acting as an acid?
PbO + 2NaOH + H₂O –> Na₂[Pb(OH)₄]
Explain why aluminium chloride forms dimers and the bonding in the dimer.
The aluminium in AlCl₃ only has 6 electrons in its outer shell so accepts electrons in a co-ordinate bond from the chlorine of another AlCl₃ molecule forming a dimer.
What is a doner acceptor compound?
Where one compound donates a pair of electrons to an electron deficient compound forming a co-ordinate bond.
Give an example of a Donor acceptor compound and explain the bonding?
NH₃BF₃
Boron trifluoride accepts the lone pair from the Nitrogen in ammonia.
Which Carbon allotrope is comparable to Cubic Boron Nitride?
Diamond
Which Carbon allotrope is comparable to Hexagonal Boron Nitride?
Graphite
What are the 3 differences between Hexagonal BN and Graphite?
RIP (Register, Insulator, Polar)
1. Atoms in adjacent layers are in register (Aligned) in Hexagonal BN, they are not in Graphite.
2. Hexagonal BN is an insulator because the free electrons in graphite are the lone pair on the Nitrogen in BN.
3. The electronegativity difference between Boron and Nitrogen gives the BN a polar bond, this is not present in graphite.
What are the uses of Hexagonal Boron Nitride? (5)
Semi-conductors - electronics
Ceramics
Microwaves
Catalyst carrier - fuel cells and batteries
Nano tubes out of single layers
What are some properties of Diamond and Cubic BN? (3)
Hard, Strong, Extremely high melting point.
Explain some differences between Diamond and Cubic BN. (2)
Diamond is harder due to lack of electronegativity difference.
Cubic BN is more stable so is preferred to diamond for grinding certain materials.
Explain the REDOX properties of the oxides of Carbon.
CO₂ is more stable than CO because of the inert pair effect being less at the top of the group. Therefore, CO can act as a reducing agent as the carbon is easily oxidised from +2 to +4.