Chemistry 3 - Rates, Equilibrium and Organic Chemistry (C8 - C11) Flashcards
How do you calculate the rate of a reaction?
Measure the amounts of reactants being used up or products being made over time.
How do you find the rate of reaction from a graph?
The gradient
How do you find the rate of reaction at any given point on a graph?
The tangent about the point.
What is the minimum amount of energy required by particles to react called?
Activation energy
Why does increasing the temperature of a reaction increase its speed?
Because there is more kinetic energy in the particles, making a larger amount of collisions between them.
What is a method other than temperature of increasing the rate of the reaction by increasing the number of collisions?
Increasing the concentration of the reactants.
How does a Catalyst speed up the rate of a reaction?
They provide an alternate route for the reaction to take place, decreasing the activation energy.
How does a reversible reaction work?
The products of the reaction can react to make the original reactants.
What is an exothermic reaction?
A reaction where the overall energy change is a decrease, energy is given out to the surroundings. A reaction where the energy required to make bonds is less than that required to break them.
What is an endothermic reaction?
A reaction where more energy is required to make bonds than is required to break them, as energy is absorbed from the surroundings.
What is an equilibrium?
A reversible reaction in a closed system where the forward and backward reactions are happening at the same rate.
What happens if you increase the temperature in an equilibrium reaction?
The reaction will favour the endothermic side, which takes in heat, and the rate of this reaction will increase.
What is crude oil?
A mixture of many different compounds, most of which are hydrocarbons.
What are hydrocarbons?
A compound made of carbon and hydrogen atoms in a covalent bond chain.
What are alkanes?
A saturated hydrocarbon. They contain as many hydrogen atoms as possible in their molecules.
What does saturated mean?
It does not have a double bond. They contain as many hydrogen atoms as possible in their molecules.
What is the formula for alkanes?
CnH(2n+2)
What is volatility?
The tendency to turn into gas.
What is viscosity?
How thick it is.
Which fractions make better fuels?
Lighter because they ignite more easily and burn well, with cleaner (less smoky) flames.
How do you separate crude oil into separate fractions?
Fractional distillation
What are the products of complete combustion?
Carbon Dioxide and Water Vapour
What are the products of incomplete combustion?
Carbon Monoxide and Water Vapour
What is cracking?
Breaking a mixture of hydrocarbons up into two or more Alkenes
What is the difference between cracking and Fractional distillation?
The difference is that cracking involves breaking bonds while fractional distillation is just separation of hydrocarbons.
What is formed in complete combustion of an alkene?
Carbon dioxide and water.
How do alkenes react with halogens, hydrogen and water?
By adding atoms across the C=C bond, forming a saturated molecule.
What is the functional group of alcohols?
-OH
What is the functional group of carboxylic acids?
-COOH
What is the functional group of esters?
-COO-
What is the main alcohol used in alcoholic drinks?
Ethanol
What are two examples of the uses of alcohols?
Any two from:
- Solvents
- Fuels
- Disinfectant (medical equipment)
- Mouth wash
What is produced when alcohols burn? (Two substances)
Carbon dioxide and Water
What solution is formed when alcohols react with sodium metal? (And what gas is given off)
Sodium alkoxide solution.
Hydrogen gas is given off.
What is the process by which ethanol can be turned to ethanoic acid?
Oxidation
How does oxidation of ethanol work?
An oxidising agent (which contains oxygen atoms) is mixed with ethanol which reacts to form ethanoic acid and water.
What happens (visibly) when carbonates are put in solutions of carboxylic acids.
They gently fizz on the release of carbon dioxide gas.
How are Esters formed?
By reacting a carboxylic acid with an alcohol in the presence of a strong acid catalyst.
Name 2 characteristics of Esters
- Volatile
- Fragrant (Used in flavourings and perfumes)
What are polymers?
Huge molecules made from lots of small molecules joined together called “monomers”.
What is addition polymerisation?
The reaction between alkene monomers to form a polymer is called addition polymerisation.
What is the reaction between alkene monomers to form a polymer called?
Addition polymerisation.
What is condensation polymerisation?
(Answer in progress)
What are polyesters?
(Answer in progress)
How are polyesters formed?
The condensation polymerisation of a diol and a dicarboxylic acid, with H2O given off in the reaction.
Give 2 examples of natural polymers
- Starch
- Cellulose
- Proteins
What are the monomers of proteins?
Amino acids.
What monomer is DNA made of?
Nucleotides
What does DNA stand for?
Deoxyribonucleic acid
What is the structure of a DNA molecule?
Two polymer strands (with sugars bonded to phosphate groups) intertwined into a double helix)
