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C3 – Chemicals in Our Lives. Starter. Element or Compound?. Sulphur. S. Carbon Dioxide. CO 2. Water. H 2 O. Chlorine. Cl 2. Sulphuric Acid. H 2 SO 4. Carbon (Buckminsterfullerene). C 60. Sodium Hydroxide. NaOH. Definitions. Element Contains only one type of Atom.
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Starter • Element or Compound?
Sulphur S
Carbon Dioxide CO2
Water H2O
Chlorine Cl2
Sulphuric Acid H2SO4
Sodium Hydroxide NaOH
Definitions • Element • Contains only one type of Atom. • Found on the Periodic Table (of elements) • Compound • Consists of 2 or more elements bonded (fixed) together
Carbon Dioxide CO2
Water H2O
Sulphuric Acid H2SO4
Sodium Hydroxide NaOH
Elements, Compounds and Rocks • Rocks are a MIXTURE of Compounds • The most common compound is Silicon Dioxide SiO2 • This is commonly known as Quartz or Silica
The Rock Cycle Three Rock Types: Sedimentary - made from sediment Metamorphic – changed by heat and pressure Igneous – formed from Lava or Magma (molten rock)
Useful Resources from Rocks • Coal (carbon) • Limestone (Calcium Carbonate) • Marble (Calcium Carbonate) • Rock Salt (Sodium Chloride) • Metal Ores (Compounds containing Metals)
What’s the use in Salt? • What can Salt be used for? • List as many things as you can. • Hint – For some, Think about the elements that Salt is made from.
Uses of Salt • Food (seasoning and preservation) • Gritting Road (melts ice) • Making Chlorine – Bleach • Making Sodium Hydroxide – Soaps and Cleaners • Making Hydrogen Gas – A Fuel
How is Salt obtained? • Evaporation of Sea Water • Mining of Rock salt • Solution mining of Rock Salt
Why use salt in our food? • Preservative (stops bacteria from growing) • Flavour enhancer (seasoning) • Makes food taste better / stronger
What is Risk? • Risk depends upon 2 factors: • Chance of something happening • Level of harm that occurs if it does
Risk • Actual Risk – A Risk calculated from actual data • Perceived Risk – A risk thought by individuals without clear data to support it
Precautionary Principle • If the risks or harm from an activity may be greater than any benefit, it makes sense to restrict or stop the activity. • This is particularly true where the level of risk is as yet unknown.
Salt and Health • Risks: High Blood Pressure, Heart Disease and Strokes • High Salt diet – Processed food with added salt • Salt is needed – but no more than about 4g per day • Current average intake in the UK: • Men - 11g of salt per day • Women - 8g of salt per day
What is an Alkali? • Chemical Compounds that contain HYDROXIDE ions (OH-) • Turn Universal Indicator Blue or Purple • Have a pH over 7, usually between 9 (weak) and 14 (very strong)
Uses of Alkalis • Making Soap • Neutralising Soil • Making Glass • Dyeing Cloth
Is it an Alkali? Sodium Hydroxide
Is it an Alkali? Water
Is it an Alkali? It turns Universal Indicator Blue
Is it an Alkali? Potassium Hydroxide
Is it an Alkali? Hydrochloric Acid
Is it an Alkali? Urea (Urine)
Is it an Alkali? Wasp Sting
Is it an Alkali? Soapy Water
Is it an Alkali? Milk