December Mocks - things to know Flashcards
directing effects of electron withdrawing groups
electron withdrawing groups have a 3-directing effect
example: NO2
how does a halogen carrier work
generates an electrophile
accepts a pair of electrons from the partially polarised covalent bond to form an electrophile
example: Fe, FeCl3, FeBr3,AlCl3,AlBr3
directing effects of electron-donating groups
electron donating groups have a 2- and 4- directing effect
example: OH,NH2
how do you name aromatic compounds
alkyl groups, halogens and nitro groups are prefixes to benzene (eg nitrobenzene)
alkyl chains containing a functional group or seven or more c atoms are suffixes (eg phenylethanone)
how do you distinguish between phenols and carboxylic acids
carboxylic acids reacts with metal carbonates to produce CO2
phenols arent strong enough to react
how do you distinguish between aldehydes and ketones
Tollen’s reagent added and mixture is warmed
aldehydes are oxidised to carboxylic acids
silver ions reduced to silver precipitate
silver mirror effect forms
how do you test for and identify carbonyl compounds
2,4-dnp
detects presence of carbonyl group:
yellow/orange precipitate forms
identify carbonyl compound from melting point of the derivative:
filter,recrystallise,dry,compare melting point to those in database to identify
standard conditions
100kPa
298k
diatomic molecules
H2, N2, F2, I2, O2, Cl2, Br2
what type of bonds are in single and double bonds
single bonds - one sigma bond
double bonds - one sigma bond and one pi bond
mechanism for depletion of ozone by CFCs
CF2Cl2
CF2Cl2 —> CF2Cl. + Cl.
Cl. + O3 —> ClO. + O2
ClO. + O —> O2
ClO. + ClO. —> Cl2O2
ClO. + Cl. —> Cl2O
Cl. + Cl. —> Cl2
mechanism for ozone depletion by NO.
P1 NO. + O3 —> NO2. + O2
P2 NO2. + O —> NO. + O2
