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Flashcards · 0620 · Topic 10

Chemistry of the environment flashcards

13 cards on Topic 10, subtopics 10.1 to 10.3. Pick a subtopic or study them all.

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10.1 Water

Two chemical tests for water
Anhydrous copper(II) sulfate turns from white to blue. Anhydrous cobalt(II) chloride turns from blue to pink.
Physical test for pure water
It melts at exactly 0 °C and boils at exactly 100 °C.
Stages of water treatment, in order
1. Sedimentation and filtration — remove solids. 2. Carbon — removes tastes and odours. 3. Chlorination — kills bacteria.

10.2 Fertilisers

NPK fertilisers: the three elements
Nitrogen, phosphorus and potassium.
Role of nitrogen, phosphorus and potassium in plants
Nitrogen: protein synthesis, leaf growth. Phosphorus: root growth. Potassium: flowering, fruit, disease resistance.
Two types of compound used as nitrogen fertilisers
Ammonium salts and nitrates.

10.3 Air quality and climate

Composition of clean, dry air
About 78% nitrogen and 21% oxygen. The rest is mainly argon, with a little carbon dioxide.
Carbon monoxide: source and effect
Incomplete combustion of carbon-containing fuels. Toxic — it reduces the blood’s ability to carry oxygen.
Sulfur dioxide: source and effect
Burning fossil fuels that contain sulfur impurities. Causes acid rain.
Two greenhouse gases and their sources
Carbon dioxide: complete combustion of fuels, respiration. Methane: livestock, decomposition of vegetation, rice paddies.
What does a catalytic converter in a car remove?
Oxides of nitrogen (and carbon monoxide), cutting acid rain.
Catalytic converter equation removing CO and NO togetherExtended
2CO + 2NO → 2CO₂ + N₂
Symbol equation for photosynthesisExtended
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂