IGCSE Chemistry CIE: Chemistry of the Environment Flashcards

Vocabulary flashcards covering water tests, purification, fertilisers, air composition, pollution, and photosynthesis based on the IGCSE Chemistry syllabus.

Cobalt(II) chloride

A chemical used to test for the presence of water that turns from blue to pink.

Copper(II) sulfate

A chemical used to test for water that changes from a white anhydrous state to a blue hydrated state.

Anhydrous cobalt(II) chloride symbol equation

$$CoCl_2(s) + 6H_2O(l) \rightleftharpoons CoCl_2.6H_2O(s)$$

Anhydrous copper(II) sulfate symbol equation

$$CuSO_4(s) + 5H_2O(l) \rightleftharpoons CuSO_4.5H_2O(s)$$

Water Purity

Determined by a specific and sharp boiling point of $100\,^\circ\text{C}$ and a melting point of $0\,^\circ\text{C}$.

Distilled water

Water that has been heated to form a vapour and then condensed back to a liquid, containing very few impurities.

Aquifer

A rock that stores water in natural underground sources.

Eutrophication

A process caused by nitrates and phosphates from fertilisers that leads to the deoxygenation of water and damage to aquatic life.

Sedimentation

A stage in water treatment where water stands in tanks, allowing mud, sand, and other particles to fall to the bottom due to gravity.

Filtration

The process of removing smaller particles by passing water through layers of sand and gravel filters.

Chlorination

The addition of chlorine to water supplies to kill bacteria and microorganisms like those that cause cholera and typhoid.

Nitrogen (in fertilisers)

An element used by plants to make chlorophyll and protein and to promote healthy leaves.

Potassium (in fertilisers)

An element in fertilisers that promotes growth and healthy fruit and flowers.

Phosphorus (in fertilisers)

An element in fertilisers that promotes the development of healthy roots.

Ammonium nitrate

A common fertiliser compound with the formula $NH_4NO_3$.

Clean, Dry Air Composition

Approximately $78\%$ nitrogen, $21\%$ oxygen, $0.9\%$ argon, and $0.04\%$ carbon dioxide.

Fractional distillation

The method used to separate oxygen and nitrogen from the air.

Carbon monoxide ($CO$)

A toxic air pollutant produced by incomplete combustion of carbon-containing fuels that prevents haemoglobin from carrying oxygen.

Oxides of nitrogen

Pollutants formed at high temperatures in car engines that cause photochemical smog and acid rain.

Sulfur dioxide ($SO_2$)

A pollutant produced by the combustion of fossil fuels containing sulfur that leads to acid rain.

Greenhouse effect

The process where thermal energy is absorbed by gases like carbon dioxide and methane and re-emitted in all directions, keeping the Earth warm.

Flue gas desulfurisation

A method of reducing sulfur dioxide emissions by reacting the gas with calcium oxide.

Catalytic converter

A device fitted to car exhausts containing platinum and rhodium catalysts that converts harmful gases like $CO$ and $NO$ into harmless $CO_2$ and $N_2$.

Photosynthesis

An endothermic reaction in green plants that uses light energy and chlorophyll to convert carbon dioxide and water into glucose and oxygen.

Photosynthesis balanced symbol equation

$$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$$