Chem paper 2 C8-10

C8

Formulations- paints, fertilisers, fuels and alloys

Chromatography separating mixture

paper chromotography

Lighter particles are drawn higher up by the mobile phase

Rf value = distance substance moved over distance solvent moved

Hydrogen

Lit splint causes a squeaky pop

Oxygen

glowing splint relights

Carbon dioxide

Limewater (aqueous calcium hydroxide) goes cloudy

Chlorine

Bleaches blue litmus paper white

C9 - Chemistry of the atmosphere

Composition of gases most likely carbon dioxide and nitrogen and water increasing because of volcanic activity

The carbon dioxide was likely dissolved into the oceans formed, then into sediment

Plants and algae then converted carbon dioxide into oxygen through photosynthesis

Greenhouse effect- water vapour, carbon dioxide and methane absorb long wavelength radiation which keeps the earth warm and now contributes to global warming due to the increase in CO2

Carbon footprint is the measure of how much carbon dioxide is released into the atmosphere as a result of your actions

Carbon monoxide binds to haemoglobin in red blood cells, reducing the oxygen they are able to transport around the body. Its odourless and colourless, making it very hard to detect

Caused by combustion engines:

Sulphur dioxide causes acid rain, which corrodes metals and erodes stone.

Nitrogen Oxides cause respiratory/ breathing problems (when nitrogen reacts with Oxygen.

Soot/Carbon particulates

Can cause health issues

C10 Using resources

Resources needed for

• warmth

• shelter

• food

• transport

Some natural resources include:

• Food

• Wood for building

• Fuels for burning, energy

• Materials for fabrics/ clothing e.g. silk, cotton

We supplement these through Agriculture, but we are also trying to Replace them with synthetic materials.

Sustainability: using natural materials in a way that does not compromise future generations’ ability to do the same

Potable Water

Water which has low enough salt and microbes that is safe to drink.

The most effective way of obtaining this is by taking it from a freshwater source e.g. river, as this will have very little salt dissolved in it.

It is then filtered to remove large insoluble particles, then sterilised using Chlorine, Ozone or UV

Desalination : remove salt e.g. saltwater by distillation or Reverse Osmosis so it is safe to drink. Disadvantage: requires a lot of energy

Treating Waste water

Waste water is produced when we go to the toilet; Also from industrial processes

Harmful chemicals and organic matter must be removed before it is released back into the environment.

Screening/grit removal Liquid effluent treated by aerobic respiration

or ----→

sedimentation Sludge (solid):

treated by Anaerobic Respiration

Extracting metals

Most metals extracted from their ores by electrolysis or displacement reactions

Copper

Phyto mining- Plants absorb copper ions into their roots from copper rich soil. These plants are then burnt and the copper is obtained form the ashes

Bioleaching- Bacteria produce leachate solutions that contain copper ions that can be extracted

disadvantage is both have very low yields (produce very little copper)

Life cycle assessment

Carried out to predict the impact of a new product on the environment

What is considered:

-Extraction and processing of raw materials

-manufacturing and packaging

-use over its lifetime

-disposal

-transportation

We can reduce the impact by:

• Using products less

• Reducing Materials and energy needed to male

• Recycling