The Chemical Industry Flashcards
Describe NO, NO2 and N2O.
NO - colourless gas - produced by combustion.
NO2 - brown gas - produced by the oxidation of NO.
N2O - colourless gas - produced by denitrifying bacteria.
What is the test for nitrate (V) ions?
NO3-, NaOH and Devarda’s alloy (Cu/Al/Zn). Aluminium acts as the reducing agent.
Turns red litmus paper blue. Forms ammonium chloride when in contact with HCl.
What is the test for ammonium ions?
NH4+ + NaOH. Ammonia gas will be given off.
Describe the Haber process.
N2 + 3H2 2NH3
Exothermic. 400-450C, 200atm (high pressure).
Iron catalyst and potassium hydroxide. `
Describe the production of nitric acid.
Oxidation of ammonia:
4NH3 + 5O2 -> 4NO + 6H2O.
Absorption of nitrogen oxides:
2NO + O2 -> 2NO2
2NO2 -> N2O4
Gases are passed through towers to meet a stream of water.
3N2O4 + 2H2O -> 4HNO3 + 2NO.
Describe the production of sulfuric acid.
Gas is purified and cooled:
S+O2->SO2
Excess oxygen is passed over a vanadium (V) catalyst at 450C:
2SO2+O2->2SO3
Oleum is formed:
SO3+H2SO4->H2S2O7
Oleum is diluted in water:
H2S2O7+H20->2H2SO4
What are the units for rate equations?
First order: sec-1
Second order: dm-3mol-1sec-1
Third order: dm6mol-2sec-1
How is the rate-determining step worked out?
The slowest step.
Identify the substances not involved in the rate equation. Identify the substances involved in the rate equation. Identify the order of the reaction.
Describe the manufacture of ethanoic acid.
Methanol + carbon monoxide.
450K, 30atm.
Exothermic.
Which 5 things should be considered in chemical manufacture?
Cost of the process, production of co-products, production of by-products, efficiency, saving energy.
Name 4 acts in legislation to ensure safety.
Health and Safety at Work Act.
Control of Substances Hazardous to Health.
Control of Major Accident Hazards.
Registration, Evaluation, Authorisation and Restriction of Chemicals.
