Inorganic Flashcards
Shapes of molecules and bond angle
Linear - 180, 2BP 0LP
Bent - 104.5, 2BP 2LP
Trigonal planar - 120, 3BP
Trigonal pyramidal - 107, 3BP 1LP
Tetrahedral - 109.5, 4BP
Trigonal bipyramidal - 90 & 120, 5BP 0LP
Octahedral - 90 & 180, 6BP
Electrons repel to point of max separation/minimum repulsion
Outline 3 types of IMF
PDPD < IDPDP < H Bonding
IDPDP - Temporary dipole in 1 molecule creates induced dipole in near molecules
PDPD - interactions between partial +ve /-ve charges between polar molecules
H bonding - when H is directly bonded to O/N/F
Simple molecular vs Giant covalent
Simple molecular:
- lots of molecules
- weak intermolecular forces between discrete molecules
- does not require a lot of energy to break
Giant covalent:
- lattice of atoms
- M,S, CB T R A L O E T B
Diamond / Graphite / Graphene
Diamond:
- M,S,CB T R A L O E T B
- each C atom covalently bonded to 4 other C atoms
Graphite:
- M,S,CB T R A L O E T B
- each C atom covalently bonded to 3 other C atoms
- delocalised electrons between layers
- able to conduct electricity
Graphene:
- M,S CB T R A L O E T B
- each C atom covalently bonded to 3 other C atom
Trend of atomic radius across period
- Decreases
- Increased nuclear charge with similar shielding
- outer electrons more strongly attracted to nucleus
Trend of atomic radius down group
- Increases
- more quantum shells so more shielding
- electrons further away from nucleus
Trend of IE across period
- Increases
- increasing nuclear charge
- similar shielding
- electrons more attracted to nucleus
- more energy required to remove
Trend of IE down group
- Decreases
- increasing atomic/ionic radius
- electrons less strongly attracted to nucleus
- less energy required to remove electron
Trend of bond length down group
- increases
- increasing atomic radius across group
Why S IE less than O IE
- electron removed is paired in p-orbital
- electrons have opposite spins and repel each other
- less energy required to remove electron
Differences between experimental and theoretical lattice energies
High difference:
- large difference due to covalent character
- state ion charge and high charge density
- large anion size
- anion electron cloud easily distorted
Group 7 boiling point trend
- Increases
- increasing electrons down group
- stronger london forces
Group 2 thermal stability trend
- increases
- ions have lower charge density
- less polarising power
- distorts anion electron cloud less
- less energy required to break bond
Group 2 hydroxide solubility trend
- increases down the group
What does similar experimental and theoretical lattice energies mean
- bonding is almost 100% ionic
Group 2 sulphate trend
- increases down the group
Outline Flame Test Procedure
- dip Pt loop in concentrated HCl
- dip into sample
- hold under non-luminous flame
Why can you not double C-C bond enthalpy to get C=C bond enthalpy
- C=C weaker than 2x C-C bonds
- made up of pi & sigma bonds, 2x sigma
How flame colours are created
- heat excites e- to higher energy level
- electrons de-excited back to original level
- energy lost via photon of light
- photon of light is colour
Silver halide precipitates
White - Cl
Cream - Br
Yellow - I
Flame colours
Li - red
Na - yellow-orange
K - lilac
Rb - red
Cs - blue-violet
Ca - orange-red
Sr - crimson
Ba - pale green
Cu - blue green with white flashes
Pb - greyish white
Describe action of catalytic converter
- influx of harmful gases (CO, NO)
- rhodium catalyst converts gases to CO2 and N2
Outline changes to MB model
Temp increase: (Decrease is opposite)
- Shifts curve to the right and lower
- Greater proportion of particles have energy greater than Ea
Outline how catalysts function
- lowers activation energy
- providing an alternative pathway for the reaction with lower Ea
Industrial comments on Haber process
- expensive due to high pressure and temperature conditions
- important for NH3 fertilisers/agriculture
- 200atm ./ 450C compromise on ROR and yield
Pros and cons of alternative fuels
Pros:
- sustainable
- less pollution than fossil fuels
Cons:
- slow process
- low percentage yield
Features and conditions for dynamic equilibrium
- closed system
- concentrations of P and R = constant
- forward reaction rate = backwards rate
Le Chatelier’s principle
Temperature:
increase temperature favours endothermic side &VV
Pressure:
increase pressure favours side w/ fewer moles of gas &VV
Concentration:
increase [reactants] favours reaction producing products &VV
Catalyst:
- no effect on POE
- increases ROR of fwd and bwd reaction
Kp and Kc
Kp:
- curved brackets
- value only affected by change in temp
Kc:
- square brackets
- value only affected by change in temp
Bronsted-Lowry acids & bases
Acid: proton donor
Base: proton acceptor
C.Acid - linked to base
C.Base - linked to acid
Lewis acid & bases
Acid: electron pair acceptor
Base: electron pair donor
Predict pH of water at temp > 298K (2019)
- neutral
- [H] and [OH-] are equal
Explain why scandium isn’t a transition metal (2020)
- last electron added is in d subshell
- so is a d block element
- does not form a stable ion with a partially filled d subshell
- state ionic electronic configuration
- state full or empty subshell
Assumptions of Ka = [H+]^2/[A]
- [HA] = [initial acid]
- No H+ come from water dissociation
Entropy
Total entropy = entropy sys + entropy surr
Entropy sys = entropy Pr - entropy Re
Entropy surr = -AH/T
Feasible when entropy is positive
Gibbs free energy
AG= AH - (TAS)
Feasible when AG less than 0
AG = -RTlnK
Why are bond enthalpy values always positive
Energy input is needed in order to break bonds
E cell calculation
OA - RC
E cell representation
Zn (Ra) and Cu (Oa)
State symbols always included
Zn | Zn2+ || Cu2+ | Cu
Why is a salt bridge used
Electrons can move without affecting the reactions
Limitations of standard E cell calculations for feasibility
- non standard conditions
- kinetic factors
Fuel cells
Pros:
- Produces electrical current without being recharged
- environmentally friendly
Cons:
- hydrogen is very flammable
- expensive to produce/make
Naming ion complexes
- Number of ligands
- Molecule attached to ligand
- Metal ion centre
- charge in roman numerals
E.g [hexaaquacopper(II)]2+ion
Ion colours in limiting NH3
cr(III) - green ppte
Fe(II) - green ppte
Fe(III) - brown ppte
Co(II) = blue ppte
Cu(II) - blue ppte
Ion colours in excess NH3
cr(III) - purple sltn
Fe(II) - no change
Fe(III) - no change
Co(II) = yellow solution
Cu(II) - dark blue solution
Ion colours in limiting NaOH
cr(III) - green ppte
Fe(II) - green ppte
Fe(III) - brown ppte
Co(II) = blue ppte
Cu(II) - blue ppte
Ion colours in excess NaOH
cr(III) - green sltn
Fe(II) - no change
Fe(III) - no change
Co(II) - no change
Cu(II) - no change
Vanadium oxidation states & colours
You Better Get Vanadium
Why is a chromium ion coloured
- Has a partially filled d-orbital
- so electrons can be promoted
Outline heterogenous catalysts function
- adsorption onto catalyst active site on surface
- bonds are weakened
- products desorbed from catalyst surface
Outline homogenous catalysts function
- combination with reactions to produce intermediate
- enthalpy change of formation of intermediate is low
- Ea reduced
Autocatalysis & catalyst poisoning
Auto - when a product acts a catalyst
Poisoning - when impurities block active sites of heterogenous catalysts
Outline TOF Mass spec process
- Ionisation - vaporisation and e- removed, making 1+ ions
- Acceleration towards -ve plate
- Deflection - deflected into curved path
- Detection - gain electron when hit the detection plate, producing flow
- Analysis
Outline TLC
Procedure on layer of silica, not paper
Movement measured using UV
Outline GLC
- powdered substance used as stationary phase
- High pressure gas used as mobile phase
- useful for separating volatile liquids
Outline column chromatography
- Mobile and stationary phases in a column
- retention times depend on sample’s affinity to stationary phase
Outline 1H NMR spec
Integration trace - number of H in that environment
Singlet - No H on adjacent C
Doublet - 1 H on adjacent C
Continues
Outline enantiomers & optical isomerism
- Chiral carbon centre makes trigonal planar carbocation intermediate
- Equal chance of nucleophile attack above and below carbocation
- Produces racemic mix of 2 enantiomers
- do not rotate plane polarised light
