3.3.3 - halogenoalkanes

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Total cards: 24•Content version: v4•Public deck•Updated: 8/1/2026

Card preview (24)

Front (Question)

what does CFCs stand for?

Back (Answer)

chlorofluorocarbons

Front (Question)

what are CFCs?

Back (Answer)

halogenoalkane molecules where all hydrogen atoms have been replaced by chlorine and fluorine atoms

Front (Question)

what is the ozone layer made from?

Back (Answer)

(O)3

Front (Question)

what does the ozone layer do?

Back (Answer)

absorbs lots of UV radiation from the sun

Front (Question)

dangers of UV radiation

Back (Answer)

• sunburn • skin cancer

Front (Question)

how is the ozone layer formed?

Back (Answer)

oxygen molecule is broken down into 2 free radicals by UV radiation

Front (Question)

first step of ozone layer formation

Back (Answer)

O2 (+UV) = O. +O.

Front (Question)

second step of ozone layer formation

Back (Answer)

O2 + O. = O3

Front (Question)

CFCs and the ozone layer

Back (Answer)

CFCs contribute to damaging the ozone layer

#10

Front (Question)

what is the first step of how CFCs damage the ozone layer?

Back (Answer)

chlorine radicals are formed in the upper atmosphere when C-Cl bonds in CFCs are broken down by UV radiation e.g. CCl3F (+UV) =.CCl2F +Cl.

#11

Front (Question)

what is the second step of how CFCs damage the ozone layer

Back (Answer)

Cl. + O = O2 + ClO. ClO. + O3 = 2(O2) + Cl.

#12

Front (Question)

what safer alternatives to CFCs have been made?

Back (Answer)

• HCFCs (hydrochlorofluorocarbons) • HFCs (hydrofluorocarbons)

#13

Front (Question)

what did CFCs mainly used to be used in?

Back (Answer)

• propellers in aerosols • fire extinguishers • coolant gas in fridges • added to foam plastics to make insulation/packaging materials

#14

Front (Question)

properties of CFCs

Back (Answer)

• pretty unreactive • non flammable • non toxic

#15

Front (Question)

what do most aerosols use now instead of CFCs as a propellant

Back (Answer)

-pump spray system - nitrogen as a propellant

#16

Front (Question)

what is now used as a coolant gas in fridges instead of CFCs

Back (Answer)

ammonia or hydrocarbons

#17

Front (Question)

what is now used to make foamed polymers instead of CFCs?

Back (Answer)

carbon dioxide is used to make foamed polymers

#18

Front (Question)

what are halogenoalkanes

Back (Answer)

an alkane with at least one halogen atom in place of a hydrogen atom

#19

Front (Question)

polarity of carbon-halogen bonds

Back (Answer)

most carbon-halogen bonds are polar

#20

Front (Question)

what is the reasoning for the polarity of carbon-halogen bonds

Back (Answer)

halogens are usually much more electronegative than carbon

#21

Front (Question)

what charges would the carbon and halogen have in a carbon-halogen bond

Back (Answer)

carbon has a slight positive charge and the halogen has a slight negative charge

#22

Front (Question)

what is the reason for the charges in a carbon-halogen bond

Back (Answer)

halogen atom is more electronegative than carbon atom so withdraws electron density from the carbon atom

#23

Front (Question)

what is a nucleophile

Back (Answer)

nucleophile is an electron pair donor, donates an electron pair to somewhere without enough electrons

#24

Front (Question)

what are some examples of nucleophiles that will react with halogenoalkanes

Back (Answer)

-cyanide ion -ammonia -hydroxide ion