chemistry - biomolecules, fuel,

12.1 - synthesis of proteins - proteins

12.2 - synthesis of carbs, lipids - carbohydrates

12.2 - synthesis of carbs, lipids - lipids

12.3 - hydrolosis of biomolecules

2.1 - Exothermic and endothermic reactions - energy + fuels

• all chemicals contain stored energy + any chemical reaction will produce an energy change

• fuels - substances that can easily release stored chemical energy by undergoing exothermic combustion reactions

2.1 - Exothermic and endothermic reactions - exothermic reactions

• exothermic reactions - release energy to the environment

2.1 - Exothermic and endothermic reactions - endothermic reactions

• endothermic reactions - absorb energy

2.1 - Exothermic and endothermic reactions - enthalpy

• enthalpy (H) - the chemical energy or heat content of a substance

• H_r - enthalpy of reactants

• H_p - enthalpy of products

• ∆H - enthalpy change - the exchange of heat energy between the system + its surroundings under constant pressure (SLC?). ∆H = H_p - H_r

2.2 - Types of fuels

2.3 - Fuel sources for the body

2.4 - Bioethanol

2.5 - Energy from the combustion of fuels

3.1 - Stoichiometry involving combustion of fuels

3.2 - Determination of limiting reactants or reagents

3.3 - Calculating heat energy released

3.4 - Solution calorimetry

3.5 - Energy from fuels and food

combustion reactions

• exothermic reaction (releases heat)

• ex. burning fuels

• incomplete combustion - oxygen is a limiting reagant

• complete combustion -

• always assume complete combustion

equations

carbon oxidation reactions

• combustion reactions in the body

fermentation reactions

• equation - C₆H₁₂O_6(aq) → 2C₂H₅OH_(aq) + 2CO_2(g)

• plants → (using yeast) bioethanol

photosynthesis reactions

• opposite of x equation

• equation - 6CO_2(g) + 6H₂O_(l) → C₆H₁₂O_6(aq) + 6O_2(g)

• plants → (using light) glucose

exothermic reactions

• reactant energy > products energy

• releases heat as a byproduct

fuels

• substance with high amount of energy stored in its bonds that can be readily accessed

fossil fuels

• 3 main - coal, crude oil/petrol, natural gas

advantages

• higher energy content than biofuel → reduces cost

• easier to transport + we already have infrastructure for obtaining, transport, processing → reduces cost

• lots of jobs involved → good for economy

disadvantages

• non-renewable

• finite resource

• production + combustion releases CO₂ into atmosphere → adds to net CO₂ emmissions → enhanced greenhouse effect → extreme weather events + climate change

• release more pollutants - ex. photochemical smog such as NO₂, SO₂

biofuels

• 3 main - biogas, biodiesel, bioethanol

• come from plant materials

advantages

• renewable - uses natural processes + made quickly

• do not add to net CO₂ emmissions

disadvantages

• lower energy content than fossil fuels

• less investment in infrastructure → more expensive

coal

• brown coal energy content -

• black coal energy content -

crude oil

fractional distillation

• fractions (different sized hydrocarbons) are seperated according to their boiling poit using a heat source

• recondense

natural gas

biogas

• low energy content - 26 kJ/g

biodiesel

bioethanol

non-renewable

produced at a rate faster tgan

CO₂ emmissions

excess release of CO₂ into atmosphere → adds to net CO₂ emmissions → enhanced greenhouse effect → extreme weather events + climate change