Rates of reaction
How does a catalyst increase the rate of reaction?
It reduces the activation energy
What is the general formula for an alkane?
CnH2n+2
What is a formulation?
A mixture designed as a useful product
Which are the three most abundant gases in our atmosphere now?
Nitrogen, oxygen, and argon.
What is a finite resource?
One that will eventually run out
Why does a reaction usually slow down as it progresses?
Concentration of reactants decreases --> less frequent collisions
Balance:
C11H24 + O2 -> CO2 + H2O
C11H24 + 17O2 -> 11CO2 + 12H2O
How might you test if water is pure?
Check whether it boils at exactly 100 degrees Celsius (or freezes at 0)
Name a process which has led to the reduction of carbon dioxide in the atmosphere over the last 400 million years
Photosynthesis, locked up in sedimentary rocks, formed fossil fuels.
What is sustainable development?
Development that meets our current needs without preventing the needs of future generations being met.
How would you find the instantaneous reaction rate at a certain time? (From a reaction graph)
Draw a tangent to the graph at the specified time and find its gradient
What is cracking?
Converting long hydrocarbon chains into short hydrocarbon chains
What colour does potassium turn in the flame test?
Lilac
Why is carbon dioxide a greenhouse gas?
It can absorb the infrared radiation emitted by the Earth, and thereby keep the heat in the Earth's atmosphere.
How is waste water treated? Give three processes that occur.
Filtration (allow removal of dirt), sterilization (allow chlorination), and desalination (allow distillation).
What is Le Chatelier's principle?
If a factor (such as a change in pressure, temperature, or concentration of a reactant) is applied to a system in equilibrium, the equilibrium will shift so as to tend to counteract the effect of the change.
What is a carboxylic acid?
Organic acid with functional group -COOH
What is the test for a sulphate ion?
Barium chloride + dilute HCl --> white precipitate will form if sulphate present.
Why is sulphur dioxide bad for the planet?
It produces acid rain when reacting with water in the atmosphere, which damages crops and marble structures.
What is phytomining?
Growing plants on low grade ores, before burning them and using electrolysis to extract and purify the metal.
If I increase the temperature of an endothermic reaction, will I get more products or reactants?
You will get more products
What is a condensation polymer?
Polymer that when formed also produces a small molecule as a by-product each time a bond is formed between two monomers (usually water)
Why do the different substances separate in chromatography?
They have different affinities for the mobile phase/different solubilities
Why are particulates bad for the atmosphere? (Give 2 reasons)
They cause global dimming AND breathing problems.
What is a composite material?
A composite material consists of two or more materials with different properties. They are combined to produce a material with improved properties. Most composite materials have two components: