Notes - Temp Flashcards
In Kinetics, the formula to work out temperature for a reaction is:
T=∆H/∆S
Pauli’s exclusion principle:
Can’t have the same set of quantum numbers
Aufbau
Fill in order of increasing energy
Hund’s
Fill singly before pairing
Heisenburg
Cant define both position and velocity of electron at any time
Principle quantum number refers to
shell
Angular quantum number refers to
orbital
Magentic quantum number refers to
orientation
Spin quantum number refers to
spin
0 order units are
mol l-1 s-1
1st order units are
s-1
2nd order units are
mol-1 l s-1
3rd order units are
mol-2 l2 s-1
To work out k, the formula is
k = rate/ [A][B]
The slow step shows the reactant dependant on the reaction so if a reactant isnt there will it be in the rate equation?
no
Order of reaction can be worked out from the slow or fast step?
SLOW
Anthing burned is always: endo or exo
Exothermic
Why is combustion exothermic?
Change of state increases disorder
What is the only thing that can affect the equilibrium constant?
Temperature!!!
Does increasing the concentration of products or reactants in the equilibrium constant do anything?
NAW, only temperature
In evaporation reactions, ∆H is
positive
In evaporation reactions, ∆S is
Positive
If ∆G is negative then equilibrium lies to the
RHS
∆G is known as Gibb’s free energy or
standard free energy
For a reaction to be feasible ∆S must be?
Positive
For a reaction to be feasible ∆G must be?
Negative
If K>1, then ∆G is
negative
If K
positive
If K=1 then ∆G is
0
In a combustion reaction the values of ∆S and ∆H are
∆S is positive, ∆H is negative
In an evaporation reaction the values of ∆S and ∆H are
∆S is positive, ∆H is positive
In the formation of snowflakes reaction the values of ∆S and ∆H are
∆S is negative, ∆H is negative
In absorption spectroscopy as the concentration of an ion in solution increases there is an increase in?
intensity of radiation absorbed
What is the best analytical technqiue to determine quantitatively the concentration of sodium ions in a urine sample?
Atomic emission spectroscopy
Moles of x in a compound formula is:
precipitate of x / gfm of x
∆H must be negative to ensure ∆G is
negative
C=C C—C are electron rich so they must be
nucleophile
Aromatics undergo what type of substitution
Electrophillic
Halides on benzene rings are more resistant to attack by
nucleophillic reagents
SN1
1 species in slow step
Reasons for avoiding SN1
Too much steric hindrance, unstable c, lack of positive inductive effect.
If a compound doesnt react with dichromate, it cannot be
oxidised
Conc, H2SO4 is used to create
C=C
Hydrolising an amide produces a
carboxylic acid
In a carboxylic acid, the propeties of the C=O and the -OH group are affected by each other? True of false
True
What is an agonist?
An agonist binds to receptor and acts like natural molecule
An antagonist does what?
Blocks natural molecules
What reagent do we use to add a CH3 to a benzene?
AlCl3
What reagent do we use to add a Cl to a benzene?
FeCl3
What reagent do we use to add a SO3 to a benzene?
H2SO4
What reagent do we use to add a NO2 to a benzene?
HNO3
To turn a haloalkane to an alcohol what reagent do we use?
KOH/NaOH
To turn a haloalkane to an ether what reagent do we use?
Potassium methoxide in methanol
To turn a alkene to an alcohol what reagent do we use?
H2SO4
To reduce an aldehyde and ketone what reagent to we use?
LiAlH4
What three reagents can be used to turn an alcohol to an alkene?
Al2SO3, H2SO4, H3PO4
IR spectroscopy is a destructive or non destructive tenchnique?
non-destructive
Elemental Microanalysis is a destructive or non destructive tenchnique?
Destructive
Mass Spec is a destructive or non destructive tenchnique?
Destructive
Proton NMR is a destructive or non destructive tenchnique?
Destructive
In IR Sepc, what is identified?
Functional groups
In IR Spec, how is IR used?
When IR is absorbed bonds vibrate
In elemntal micro, what is determined?
Empirical Formula
In Mass spec, what is identified?
Molar mass and structural features
In Mass spec what happens
sample vapourised, bombared with electrons, form positive ions and the ions follow a path according to their mass/charge ratio
In proton NMR, there are two types which are?
Low Res and High Res
An ammine is NH_?
NH3
What decreases when an acid is diluted?
[H+]
Ka measures what?
The dissociation constant of an acid
A strong acid will have a greater or lower Ka than a weak acid?
Greater
Which has a greater entropy? Secondary or Primary alcohols?
Secondary alcohols
The formula for the dissociation constant is Ka=
Ka= [product]/[reactant]
In a reaction of acids and bases, the molecule with X+ is the conjugate ____?
Acid
In a reaction of acids and bases, the molecule with X- is the conjugate _____?
Base
Salt explanation for strong base: What removes the H+ ions from the water equilibrium?
Conjugate base
Salt explanation for strong base: Removal of the H+ ions causes the water equilibirum to shif to the
RHS
Salt explanation for strong base: Equilibriu shifting to the RHS produces excess?
OH- ions
What does accurately mean, in to weigh accurately?
Mass must be in region of ___ and the exact mass must be known.
Alcohols are less volatile than their isomeric ethers because of?
hydrogen bonding
A racemic mixture contains equal amounts of two optical isomers and is optically active or inactive?
Optically inactive
What is not always trust at 298K?
[H+] = [OH-] = 10-7 mol l-1
Formula for percentage mass calculations:
GFM of x/GFM of compund multiplied by sample size
A carbon with four bonds, becomes tetrahedral so is it planar?
No
Is benzene planar?
Yes
For the hydrogen environments, look at how many hydrogens are joined on using the formula?
N+1
Pure haloalkanes joining on to a molecule is
addition
When pure haloalkanes join on to a molecule, they form bonds to?
Both carbons, making a triangle shape
In quantum numbers: if l=0 what orbital is it?
S
In quantum numbers: if l=1 what orbital is it?
P
In quantum numbers: if l=2 what orbital is it?
D
As the number of alternating single and double bonds increases the energy difference
between the HOMO and the LUMO decreases.
Describe recrystallisation
Dissolve in solvent, heat to dissolve target compound and impurities then filter to remove solid impurities, leave to cool.
What would be drawn for the hydrolysis of ethyl benzoate?
a condenser and round bottom flask correctly assembled with the condenser, ethyl benzoate and sodium hydroxide labelled.
