saturated or not? learning objectives: identify saturated & unsaturated compounds discuss the...
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Saturated or Not?
Learning Objectives:
•Identify saturated & unsaturated compounds•Discuss the role of fats in the diet
•Explain how vegetable oils can be made into biodiesel
Ethane
Dodecene
Hexacosane
Hex-2-ene
C6H12
C6H14
Saturated
Unsaturated
Decolourises bromine
Brown solution with bromine
Burns with a sooty flame
Burns with a dull flame
Burns with a clean flame
Formed when fats are
hydrogenated
Used as monomers to
make polymers
Fats in the diet
Advantages• Both saturated and non saturated
fats are needed for a healthy balanced diet
• Foods rich in fats and oils are rich in vitamin E
• Omega 3 and 6 oils are good for the brain, heart, and joints
• Cholesterol is needed to make hormones and cell membranes
• Lipids are useful energy storage molecules (adipose tissue)
• Hydrogenated fats have longer shelf life
Disadvantages• Too many saturated fats can lead
to heart disease etc…• Hydrogenated trans fats raise LDL
levels lower HDL levels and inc risk of CHD. They cannot be metabolised so stay in blood longer
• Trans fatty acids are not kinky! Act like saturated fats
• Kosher/Halal/suitable for vegetarian/vegans
• Limited evidence suggested it may have a role in some cancers, liver disease, Alzheimer’s diabetes
Veggie Power• Vegetable oil contains a lot of energy it can be used as a
fuel – biodiesel.
• Biodiesel is a CLEAN fuel• It is RENEWABLE• It is CARBON NEUTRAL• Helps to reduce use of crude oil
• The vegetable oil is chemically digested to make it a better fuel
Bioethanol
• Produced from fermenting sugar from crops• RENEWABLE and CLEAN
• Glucose ethanol + carbon dioxide
• C6H12O6 2C2H5OH + 2CO2
• Ethanol is a good fuel, it burns easily in air to form CO2 and H2O
yeast
yeast
Non Renewable Ethanol
Ethene + steam Ethanol + hydrogen
Ethene comes from CRACKING crude oil products (Remember oil is heated to 800°C with a CATALYST – long chain ALKANE broken down to smaller alkene + alkane)
Ethanol produced chemically from crude oil is still cleaner as a fuel but it is NON RENEWABLE
catalyst
High pressure
• Workbook pages 85-88 to be completed for