Chemistry GCSE: the Haber process

why is the Haber process carried out?

to produce ammonia which is used to make nitrogen based fertilisers

what are the raw materials used in the Haber process?

nitrogen, hydrogen

where is nitrogen sourced from?

the air, it gets fractionally distilled

where is hydrogen sourced from?

natural gas-the reaction between methane and steam

describe the conditions needed to undergo the Haber process

iron (catalyst), 450C temperature and 200atm pressure

what type of reaction occurs in the Haber process?

reversible

what happens after the hydrogen and nitrogen have reacted?

the mixture is cooled and condenses to liquid ammonia which is removed and the remaining hydrogen and nitrogen are recycled

what is the pressure a compromise between?

yield and cost

what is temperature a compromise between?

yield and rate

why is iron used?

to speed up the rate of reaction and allow it to operate at a lower temperature and pressure so less energy is needed

what is the problem with obtaining nitrogen?

high energy cost for extracting it from other gases in the air by fractional distillation, air has to be cooled to -200c so it condenses

what is the problem with obtaining hydrogen?

it is expensive to get it from fossil fuels

how do we improve yield in the Haber process?

high pressure, low temperature, removing ammonia

how do we improve rate of the Haber reaction?

high pressure, high temperature, iron as a catalyst