15. chemistry of the environment

Question 1

how to provide a clean safe water supply

Answer 1

1 find the cleanest source u can to pump water from
2 remove as many solid particles as you can (filtration, sedimentation, flocculation)
3 remove as many unwanted dissolved compounds as u can
4 add something to kill microbes (eg chlorine)
5 store the water safely ready to pump to taps or tankers

Question 2

mordern treat plant 15.3!!!

Question 3

fertiliser

Answer 3

any substance added to the soil to make it more fertile

Question 4

NPK fertiliser

Answer 4

mixture of salts that provides all three elements that plants need: nitrogen, phosphorus, potassium

Question 5

reactions to make synthetic fertilizers

Answer 5

1 ammonia + nitric acid –> ammonium nitrate
NH3(aq) + H3PO4 (aq) –> NH4NO3 (aq)

2. ammonia + phosphoric acid –> ammonium phosphate
   3NH3 (aq) + H3PO4 (aq) –> (NH4)3PO4 (aq)

Question 6

composition of air

Answer 6

nitrogen 78%
oxygen 21%
rest (mainly argon + co2 and noble gases eg helium) 1%

Question 7

15.5!! !5.6

Question 8

catalytic convertors

Answer 8

pg 197