Paper 2 from book Flashcards
Give 2 ways rate of reactions are affected:
Surface area - surface area to volume ratio
Concentration - More particles = more successful collisions
Temperature - An increase in energy makes particles move quicker.
Catalyst - speeds up a reaction without chemically changing the reaction
Gradient equation
Change in x/ Change in y
Fill: Chemical reactions can only occur when r_______ particles c______ with enough e_____ for the c________ to be s_________.
Fill: Chemical reactions can only occur when reacting particles collide with enough energy for the collision to be successful.
Why does temperature affect the rate of reaction?
Particles heated —> more energy —> faster —> greater frequency of collisions —> faster rate of reaction
Why does increasing concentration increase the rate of reaction?
Higher concentration —> particles closer together —> more collisions —> rate of reaction increases
Why does a larger surface area increase the rate of reaction?
More particles exposed to the other reactant —> greater chance of particles colliding —> more successful collisions per second —> rate of reaction increases
Define a catalyst.
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A substance that speeds up a chemical reaction.
What might a catalyst be used for? (Give something you may use in life)
Hand warmers
Why are catalysts used in industry?
Cheaper because they can be re-used.
How can we measure the rate of reaction? Also, give formula.
Measuring the amount of product formed over a certain period of time.
Reaction rate = change in mass OR reactant OR product/ time
Rate of reaction other formula/
1/ time (seconds)
Units are s to the power of -1
Define a reversible reaction.
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A reaction in which the products can re-form the reactants.
Define an endothermic reaction.
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A reaction that takes in energy from the surroundings.
Define an exothermic reaction.
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A reaction that transfers energy to the surroundings.
Define Anhydrous.
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Describes a substance that does not contain water.
The pH scale goes from 1 to 14. What is 1 to 6, 7, and 8 to 14?
1 to 6 = Acids
7 = Neutral
8 to 14 = Alkaline/ base
Give their number on pH scale (you can be 1 off either side).
Water =
Lemon =
Bleach =
Water = 7
Lemon = 2
Bleach = 13
Define a closed system.
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A system in which no matter enters or leaves.
Define the equilibrium.
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The point in a reversible reaction at which the forward and backward rates of reaction are the same. Therefore, the amounts of substances present in the reacting mixture remain constant.
What is Le Chatelier’s principle?
The idea that if you change the conditions of a reversible reaction then the position of equilibrium will shift to try and counteract that change.
In terms of reactants and products, what is a forward reaction and a reverse reaction?
A forward reaction = reactants to products
A reverse reaction = products to reactants
Match the prefix to the number
Prefix. |No. Carbon atoms
——————————————
meth -
but -
prop -
eth -
pent -
hex -
Prefix. |No. Carbon atoms
——————————————
meth - 1
but - 4
prop - 3
eth - 2
pent - 5
hex - 6
Fill: Crude oil is a f_____ resource found in rocks. It was formed over millions of years from the remains of tiny, ancient s__ a______ and p_____, mainly plankton, that were buried in mud. Over time, layer upon layer of rock was laid down on top, creating the conditions (high pressure and temperature, in the absence of oxygen) to make c____ o__.
The process of d___________ is used to seperate crude oil into fractions. This is because the different fractions have different b______ p_____.
Crude oil is a finite resource found in rocks. It was formed over millions of years from the remains of tiny, ancient sea animals and plants, mainly plankton, that were buried in mud. Over time, layer upon layer of rock was laid down on top, creating the conditions (high pressure and temperature, in the absence of oxygen) to make crude oil.
The process of distillation is used to seperate crude oil into fractions. This is because the different fractions have different boiling points.
Which is which?
What we change
What we measure
What we keep consistent (reliability)
What we change - independent variable
What we measure - dependent variable
What we keep consistent (reliability) - control variable
How many years left of crude oil in the world?
47
Give 2 uses of crude oil:
- vehicle fuel
- heating buildings
- producing electricity
- can be converted into petroleum products.
What is biodiesel?
Biodiesel is a renewable, biodegradable fuel manufactured domestically from vegetable oils, animal fats, or recycled restaurant grease. Biodiesel meets both the biomass-based diesel and overall advanced biofuel requirement of the renewable fuel standard.
Give one pro and one con of using biodiesel as a fuel:
Pros:
Can reduce the need for landfill space.
Cleaner than fossil fuels when they burn.
Cons:
Expensive to produce
Takes up land that could be used for food production
Define carbon-neutral.
Making or resulting in no net release of CO2 into the atmosphere, especially as a result of carbon offsetting.
Why is there still slightly more CO2 released into the atmosphere overall than the amount of CO2 absorbed by the growing crop?
- Burning fossil fuels and changing land use.
- Trees are are meant to absorb CO2, but humans release that CO2 back into the atmosphere by either burning them or letting them rot after the deforestation process.
Define a flashpoint.
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The lowest temperature at which vapours of the substance will ignite.
Define the relationship between the number of carbon atoms in the alkane and the alkane’s flashpoint.
The higher the number of carbon atoms, the higher the flashpoint.
How is crude oil separated by fractional distillation?
Crude oil is heated to produce vapour. Vapour cools to separate different compounds.
S____ chain hydrocarbons are more u_____ and in h___ demand.
L___ chain hydrocarbons need to be broken down to form these short chain h___________.
In t______ c_______, high temperatures and p________ are used to break the large hydrocarbons into smaller ones. C_______ produces alkenes, which are useful as feedstock for the petrochemical industry.
Short chain hydrocarbons are more useful and in high demand.
Long chain hydrocarbons need to be broken down to form these short chain hydrocarbons.
In thermal cracking high temperatures and pressures are used to break the large hydrocarbons into smaller ones. Cracking produces alkenes, which are useful as feedstock for the petrochemical industry.
Name 3 problems with using crude oil.
- Fossil fuel
- Oil spills can be deadly
- Non-renewable
- Can cause conflict
- Drilling is dangerous
Define pure.
Something that has not been mixed with something else. A chemical that contains one substance eg. pure water is just H20
S_____ + s_____ = s_______
Solvent + solute = solution
A formulation is a m______ that has been designed to do something useful.
mixture
What is the flame colour of these chemicals?
Sodium chloride
Potassium chloride
Lithium chloride
Magnesium chloride
Copper chloride
Sodium chloride = vibrant orange
Potassium chloride = lighter/ paler orange
Lithium chloride = crimson red/ purple
Magnesium chloride = none
Copper chloride = blue/ green streaks
Give a benefit and a negative of using a flame test to identify ions.
Speed (quick)
Simple
Colours can be hard to differentiate.
Colour blind people will struggle to identify them.
Define precipitate.
Aisfom2s
An insoluble solid formed on mixing 2 solutions.
Define combustion.
Combustion is another name for burning.
In a combustion reaction, fuel is burned and reacts with oxygen to release energy.
What is needed for a combustion reaction to take place?
Oxygen
Heat
Fuel
Name their discovery:
JJ Thompson
Rutherford
Chadwick
JJ Thompson = Electrons
Rutherford = Alpha scattering . Nucleus positive and most mass is concentrated there.
Chadwick = Neutrons in nucleus
How can we measure CO2 levels?
Ice cores - taken from Artic + Antarctica. Monitors CO2 levels over period of time.
Tree rings - larger the gap between them, the more growth, more photosynthesis, more CO2 absorbed.
