Fertilisers Flashcards
What are the 3 main elements plants need
- Nitrogen (N)
- Phosphorus (P)
- Potassium (K)
All fertilisers and nutrients must be …
Soluble
How do we make ammonia in a lab - state the general equation
Ammonium salt + alkaline/base -> ammonia + salt + water
Name a specific equation for making ammonia in the lab - and symbol
Ammonium chloride + calcium hydroxide -> ammonia + water + calcium chloride
2 NH4Cl + Ca(OH)2 -> 2 NH3 + 2 H2O + CaCl2
What colour is ammonia gas
Colourless
What colour would ammonia turn pH paper
Blue - alkaline
What do you make when you dissolve ammonia gas in water?
Ammonia hydroxide - this is because ammonia is a hydroxide gas. It would form ammonia ions and hydroxide ions
How do you make ammonia through an industrial method? Name it and give a general word equation + symbol
Haber process -
Nitrogen + hydrogen ammonia
N2 (g) + H2 (g) 2 NH3 (g)
What temperature and ATM do producers use to make ammonia through the haber process
450C and 200atm
What catylist do they use with the haber process
Iron
Catylists can be _____
Reused
What are the 3 conditions for the haber process
- temperature
- pressure
- catylist
Where do the reactants of the haber process come from
N - from the air
H - from the natural gas
What is the equation for the percentage mass composition calculations
Mass of element in compound X100
GFM of compound
Calaculate the percentage of nitrogen in ammonium sulphate
21.21%
What is the process called when making nitric acid
Ostwald process
What is step one of the Ostwald process
Ammonia + oxygen -> nitrogen monoxide + water (g)
What is the second step of the Ostwald process
Nitrogen monoxide + oxygen -> nitrogen dioxide
What is the 3rd stop of the Ostwald process
Nitrogen dioxide + water (l) + oxygen -> nitric acid
The oxidation of ammonia is _____
Exothermic
What catylist is often used in the Ostwald process
Platinum
Nitric acid can be reacted with _____ to produce ________ which is very soluble and can therefore
Ammonia, ammonium nitrate, be used as a fertiliser
Ammonium nitrate contains a high concentration of _____ which is essential for plant growth
Nitrogen
