Things I have learnt from Qs Flashcards
What type of molecules have 3 atoms in a row in it + example
ones with 6 atoms around the central atom
SF6
How do you find the overall charge of a metal complex
sum up the charges of individual ions
what is a buffer made of?
weak acid and ITS conjugate base
What state are the elements in in enthalpy of formation AND how many moles are produced?
+1 more thing to remember
-standard
-1 mole
-diatomics
Why does ethoxyethane (an ether) exhibit H bonding when mixed with water?
due to similar shape to water
If an (amine) has a longer chain, what does this mean for volatility and solubility
both decrease
haloalkane+alkoxide->
ether
what is condensation?
when 2 molecules join together and a small molecule (e.g.water or H) is removed from where they join
For markovnikov, which atom of a monohaloalkane joins to the C with more H?
HYDROGEN
haloalkane+e.g. ethanolic potassium cyanide
->nitrile->hydrolysed with dilute acid->carboxylic acid
how can you tell reduction has taken place
+H (less O in ratio)
Why can benzene not take part in addition reactions? e.g. with Br
no C=C double bond
In Sn1, how many molecules are in the rate determining step?
+what if a molecule is 0 order
1
0 order has no impact
What if a substance readily absorbs H2O?
It has a changing mass so is unsuitable as a primary standard
Should primary standards be soluble or insoluble in H2O
soluble
When asked to ‘calcule temp when reaction is just feasable’, do you need <>
no
What if the energy gap between d orbital subsets is small for metal complexes
electrons can be promoted more easily as less energy is required (longer wavelengths absorbed ->e.g.red)
When electrons are promoted, what can this make?
unpaired electrons
If there is an odd number of electrons in a subshell, what does this always mean?
There are unpaired electrons
What can test for the presence of copper ions?
flame test/atomic emission/atomic absorption
Describe weighing accurately approximately
The sample is weighed out as close as possible to the desired value but the EXACT value is KNOWN (not recorded)
rate equation
rate=k[][]
k rate constant units remembering statement
lovely mini skunk
What happens when an equilibrium reaction in which 2 enantiomers are formed (enantiomers in equilibrium with each other) is left for a while
optical activity decreases as racemic mixture forms
If there is an arrow with a substance above or below it in an equation, what is it?
a catalyst
what acts as a catalyst in the fries arrangement?
AlCl3
What is required for the initiation step of Br2 in a free radical chain reaction mechanism for the substitution of a Br atom?
UV light
What must be included in a heating by reflux diagram?
-be cross sectional with inner wall mechanism
-be an open sustem
-be sealed around the flask neck
-water in at bottom and out at top
How can the products of hydrolysing an ester be described and what happens to the layers when all the ester is hydrolysed?
-soluble as they both contain polar groups
-there is only a water soluble layer left
why is the solution of the salt sodium 4-hydroxybenzoate pH>7
1-4-hydroxybenzoate ion removes H+ by joining together to form molecules of 4-hydroxybenzoic acid
2-H2O equilibrium shifts to right to replace H+ ions and this increases the OH- ions making pH>7
What happens to molecule properties when there is a lack of H bonding?
molecules are further apart so the bp is lower
lower solubility in water
how would you name
—>—O—
2-methoxy-2-methylpropane
What MUST you show in the sn1 mechanism?
show that the - charge is going to the carbocation with arrow
What is an alkoxide?
the H in -OH is substituted for a metal
what id a nitrile group?
-C triple bond N
where can you find ionic radii
data book
INDICATOR REMINDER
DONT GET MIXED UP BETWEEN NAMES
what does exothermic mean?
a decrease in enthalpy of the SYSTEM
Is 🔺S + or - for exo reactions?
-
Is 🔺G + or - for exothermic reactions?
-
How many pi bonds to sp2 and sp3 bonds have
sp2->1
sp3->0 only sigma
What must you remember when counting sigma bonds
Hs
Are the bonds in benzene equal or unequal length?
equal
what is a planar molecule?
flat
What do drugs bind to?
the receptor
what reagent is used for -CN -> -COOH
Dilute HCl (aq)
what is emission spectra?
a series of lines at discrete wavelength that correspond to different electron transitions
FIRST WORD STARTS WITH S AND THE SECOND STARTS WITH F. WHAT IS IT????
SIGNIFICANT FIGURES
Towards what side does K increase
product
what do these mean in molexules
-dashed line
-wedged line
-into page
-out of page
what dies a double bond mean for repulsion
electron rich so more repulsion
are charge and oxidation normally the same
yes
what order do reactants that don’t take part in the rate determining step
0
what units are used in ppm
mL and L
mg and L
dative covalent bond
both electrons are from the same atom
bond description for geometric isomers
restricted rotation or lack of FREE rotation
are the number of moles the same in diluted nad undiluted?
yes
breaking C=C steps
1-addition of HBR
2-substitution
shape of 1 d orbital
4 leaf clover (holds 2 electrons)
Acid-donate or accept H
DONATES
what acid does -chloride come from?
hydrochloric
what is ammonia?
a weak acid
What happens in reaction if P is 1st order and Q is 2nd order?
2 particles of P react with 1 of Q in rate determining step. 2nd Particle of P must react in another step
What always happens as concentration decreases
ROR decreases
what happens to ROR when 1st order reactants are doubled?
Doubles
C-H hybridisation (if C forms 4 single bonds) and C triple bond c hybridisation
sp3
ONLY sp hybridisation
hydrolysis
adding H20 at break to make 2 molecules from 1
what is the filtrate?
the substance passed through the filter
How would you find n in Na2CO3•nH2O
find masses of Na2CO3 and H2O
convert into moles to get ratio
What to say instead of unfilled d orbitals
INCOMPLETE
what shoudl yoy remember to do when using 🔺S in equation
CONVERT
Feature that allows for coloured compounds
conjugated system
diagram for TLC
beaker
paper
solvent below line
line
2 spots (pure and extract)
In distillation, in what circumstance can pure substance not be extracted
if boiling points are similar
how manh peaks does H in hydroxyl have in H NMR
1
what does ‘reaction is first order with respect to both reactants’ mean
each reactant is order 1
overall reaction=order 2
what to use instead of ‘made’
prepared
how to make a calibration graph
1standard solutions prepared
2a suitable filter
3-mention of blank/solvent only measurement
4-absorbance of each is plotted
what to write instead of propanol
propan-1ol
how would you test no more ions remain in solution
add more of a reactant and no more precipitate should form
what is the precipitate?
the insoluble solid product
% by mass qs
1-Find % of (GFM of ion/element)/(GFM of precipitate) x 100
2-Use % to find mass in precipitate
3-May need to change into moles if there is a mole ration OR concentration change
4-use % mass formula with element/ ion and og sample
what must you do with the volume required to make a solution of potassium sulfate K2SO4 if finding potassium soncentration
half it since there are 2 particles for every sulfate
Name an unsuitable primary standard
NaOH
What could be used to dilute by a factor of 10
25cm3 pipette and 250cm3 standard flask
If finding oxidation number of Cr2 what must you do
divide by 2
What does the equation look like and why?
Na2CO3•10H2O
heating will release 10 H2O molecules so that only NA2CO3 remains
how many steps is hydrolysis
1
how many steps is the addition to an alkene
2
If moles of X2Y is 1, what is the moles if X
2
what do you need to remember when drawing skeletal formula of ethers
write in O
how are the orbitals Chromium and copper filled?
an electron borrowed from 4s
If given the 🔺G for several reactions, how do you work out the 🔺G for another reaction
Add together the free energies of turning the reactants of this other reaction into their products (flip any that are the other way around)
What state is Br2 at room temp?
liquid
elements that are:
-liquids
-gases
-solids
-mercury and bromine
-all the noble gases
-O2, N2, H2, Cl2, F2
-the rest are solids
What graph could be produced for a 0 order reactant X
-[X] against time
-indirectly proportional
-concentration of X would decrease as time decreases since X is used up as the reaction proceeds
-rate against [X]
-straight line
What graph could be produced for a
1st order reactant X
-[X] against time
-decaying exponential curve
-rate against [X]
-directly proportional straight line
What graph could be produced for a 2nd order reactant X
-[X] against time
-curvier decaying exponential curve
-rate against [X]
-Increasing exponential curve
What sort of reaction is involves homolytic fission?
alkane->monohaloalkane
This is free radical chain reaction substitution. Radicals in initiation step are formed by homolytic fission
What reactions involve heterolytic fission
-nucleophilic and electrophilic substitution
-electrophilic addition
What type of amines have a lower melting point
tertiary because of lack of H bonding
What must you say when describing how colour is produced in elements
when electrons fall down to LOWER ENERGY LEVELS
How is ammonia written in complexes?
amMine
Techniques used to determine concentration of ions in compound
-colorimetry
-atomic emission/absorption spectroscopy
-precipitation
How to tell if sn1 or sn2 will occur
If carbon is primary, sn2 will most likely occur
how would you write the molecular formula for a carboxylic acid and its ion
CH3COOH
CH3COO-
Watch out for equilibrium calculation questions and, also, what should you watch out for?
concentrations can be used if it’s in a 1litre container
what type of reaction is dehydration?
elimination
What is electrophile in HBr?
H
describing why a salt solution is alkaline
The ion from the salt reacts with H+ from the water
The water equilibrium shifts to the right
what sample is used in mixed melting point analysis
only a mix of sample and pure
