11. Air and Water
Core
-describe the composition of clean air as
being approximately 79% nitrogen,
20% oxygen and the remainder as being a mixture of noble gases, water vapor and carbon dioxide
-name the common pollutants in the air as being
carbon monoxide, sulfur dioxide,
oxides of nitrogen and lead compounds
-state the source of each of these
pollutants:
-carbon
monoxide from the incomplete combustion of carbon-containing substances
-sulphur dioxide
from the combustion of fossil fuels which contain sulphur compounds (leading to 'acid rain')
-oxides
of nitrogen and lead compounds from car exhausts
-state the adverse effect of common pollutants on
buildings and on health
-name the uses of oxygen in oxygen tents in
hospitals, and with acetylene (a
hydrocarbon), in welding
-describe
methods of rust prevention: paint and other coatings to exclude oxygen; [Redox]
-describe
the formation of carbon dioxide: as a product of complete combustion of carbon-containing substances
as a product of respiration
as a product of the reaction between an acid and a carbonate
-describe the need for nitrogen-, phosphorous-
and potassium-containing fertilisers
[Reversible reactions – Haber process]
-describe the displacement of ammonia from its salts [Reversible reactions – Haber process]
Extension
-describe and explain the presence of
oxides of nitrogen in car exhausts
and their catalytic removal
-describe
the separation of oxygen and nitrogen from liquid air by fractional distillation
-describe sacrificial protection in terms of the
reactivity series of metals and
galvanizing as a method of rust prevention [Redox & Electrochemistry]
-describe the essential conditions for the
manufacture of ammonia by the Haber
process including the sources of the hydrogen and nitrogen, i.e. hydrocarbons or steam and air [Reversible
reactions]