Question | Answer |
where are primary alcohols attached ?
to carbon at end.
and has CH2 OH group. | |
where are teritiary abd secondary alcohols?
secondary attached to carbon attqchee to 2 other carbons. contain CH(OH) group.
tertiary attached to carbon attached to 3 other carbons. no hydrogen atoms | |
why are alcohols liquid at room temp?
Hydrogen bonding between alcohol mole.
Oxygen hydrogen bond very polar due to difference in electronegativity. | |
why are the oxygen and hydrogen bond very polar?
difference in electronegativities. | |
when does a primary alcohol produce a carboxylic acid?
when heated under reflux WITH oxsidising mixture. ( CH3CH2OH + 2[O]--> CH3COOH + H20
distilation tube.water in water out , electric heater.
flask condenser | |
For distillation and reflux?
the glass is open at top for reflux and open at receivibg end for distillation. | |
what is formed in reaction with metallic sodium?
hydrogen gass and sodium ethoxide.
(anion neg sodium pos)
excess ethanol evaporated and sodium ethoxide seen as white solid. | |
what happ if water added to sodium ethoxide ( white solid)?
ethoxide ion acts as base
removes proton from water
forming alkaline soultion of sodium hydroxide. | |
what happ in halogenation?
the OH group removed.
replaced with halogen. | |
what hap when phosphorus pentachloride added to dry alcohol?
clouds of hydrogen choride fumes .
mixed with chloroalkane.
phosphurus oxychloride remains in vessel. | |
what hap when alcohol heated under reflux with KBr and 50% sulf acid?
HBr produced.
reacts with alcohol form bromoalkane,+water.
acid used 50% conc PREVENT HBR PRODUUCED BEING OXIDISED BY ACID TO BROMINE. | |
Warming mixture of damp RED PHOSPHURUS and I makes?
phosphorus triiodide.
then reacts with alcohol to form iodoalkane and phosphorus(III) ACID .
MOSITURE TO BRING iodine and P in CONTACT . both SOLID. | |
IODINATION?
I2 and moist phosphurus
warm
iodoethane
substitution. | |
BROMINATION
Kbr - reagent
conditions- heat ubder reflux.
product - bromoethane
reaction- substitution. | |
Chlorination
Reagent- PCl5
conditions: room temp
product: chloroethane
reaction: substitution | |
name procedure for test for alcohols?
Add PCl5 to dry substance under test.
ALL ALCOHOL produce steamy fumes of HCL.
Same result for carboxylic acid - test for OH. | |
What does a positive result for test for alcohols mean?
that a OH group is present. | |
what hap when glass rod dipped in concentrated ammonia held in fumes?
steamy fumes of HCl produce white smoke ammonium Cl. | |
what PH do alcohols have?
neutral.7 | |
Do tertiary alcohol change the colour of heated solution of Kdichromate and sulphuric acid?
No | |
what colour do primary secondary and tertiray alcohols change Kdichromate and sulfuricA?
primary and secondary - from organge to green.
tertiary stay organe. | |
what hap when S.alcohol (CH3CH(OH)) warmed with mixture of iodine and NaOH solution?
pale yellow precipitae formed.
of triiodomethane, CHI3. | |
What is a halogenoalkane?
a compound which one or more hydorgen atoms in an alkane
replaced by halogen atoms &
has onpy single bonds. | |
What is halogeoalkanes formula?
CnH(2n+1)X
X is halogen atom.
named from parent alkanes. | |
Halogens being electronegative cause?
carbon halogen bond in halogenalkanes polarised .
carbon atom pos halogen neg. | |
what are C2H6Cl C2H6Br and ClCH4 standard states?
All GASES at room temp .
ICH4 and higher members of series- Liquid | |
why do halogenoalkanes have higher BP than alkanes?
More elctrons
so stronger instantaneous induced dipole - induced dipole forces BETWEEN MOLECULES.
ALSO POLAR.
permanent dipole dipole forces BETWEEN MOL.
stretghten intermolecular forces.
increase | |