Chemistry chap 10 ++

ammonia

Source of hydrogen for haber process

Obtained from the cracking of crude oil

Source of nitrogen for Haber process

Obtained from the fractional distillation of liquid air

composition of air

78% nitrogen 21% oxygen

Suitable catalyst

Finely divided iron to increase the speed of reaction

Obtain ammonia from salts ionic reaction

Nh4+(aq) + oh-(aq) —> NH3(g) + h2o(l)

Make ammonia equation (haber)

N2(g) + 3H2(g) <> 2NH3(g)

optimal conditions for Haber process

Pressure of 250 atm

Temperature of 450 degrees

Finely divided iron catalyst

how does pressure affect yield and speed of haber process

Higher pressure gives higher yield of ammonia and increased speed of reaction, but expensive.

How does temperature affect yield and speed of haber process

Lower temperature increases yield as it reduces decomposition of ammonia back into nitrogen and hydrogen, but it slows down the reaction.

Test for OA

Acidified potassium iodide turns from colourless to brown when added to an OA.

Test for RA

Acidified potassium manganate turns from purple to colourless when added to an RA.

Use of calcium hydroxide in soil

Used to neutralise excess acidity in soil. Should not be done at same time as nitrogen fertilisers as they will react with each other. Loss of nitrogen content as nitrogen gas escapes into the atmosphere.

Use of ammonium sulfate in soil

Used to provide plants with nitrogen which is essential for plant growth.