Unit 2 Flashcards
What’s a fuel?
A chemical which is burned to produce energy
Do esters float on water?
Yes
What’s another word for burning?
Combustion
What does a substance react with when it burns?
Oxygen
What’s the chemical compounds which are mainly found in oil and natural gas?
Hydrocarbons
What does a hydrocarbon contain?
Hydrogen and carbon only
What do hydrocarbons produce when burned in a plentiful supply of oxygen?
Carbon dioxide and water
What’s the test for carbon dioxide?
Turns lime water milky
Are carbon and carbon monoxide poisonous gases?
Yeap
When are carbon and carbon monoxide produced?
When hydrocarbons burn in a supply of oxygen which is insufficient for complete combustion
How are nitrogen oxides (poisonous gas) formed?
Nitrogen and oxygen from the air react inside a petrol engine
What is released into the atmosphere from the burning of fuels?
Sulphur dioxide the poisonous gas
Whats produced by incomplete combustion of diesel (harmful) ?
Soot particles
How can air pollution from the combustion of hydrocarbons be reduced?
By the use of catalytic converters which speed up the conversion of pollutant gases to harmless gases
What is crude oil a mixture of?
Chemical compounds, mainly hydrocarbons
What is fractional distillation?
The process used to separate crude oil into fractions according to the boiling points of the fractions
What’s a fraction?
A group of hydrocarbons with boiling points in a given range
Which properties are related to molecular sizes of the molecules within the fractions and the use of fractions? (4)
Ease of evaporation
Viscosity
Flammability
Boiling point range
What’s the homologous series?
A set of compounds with the same general formula and similar chemical properties
What are subsets of the hydrocarbons? (3)
An alkane
An alkene
A cycloalkane
What are isomers?
Compounds with the same molecular formula but different structural formula
What can an alkanol be identified from?
The hydroxyl group and the “-ol” ending
What can an alkanoic acid be identified from?
The carboxyl group and the “-oic” name ending
What can an ester be identified from?
Estée group and “-oate” ending
How can an ester be named?
Given the names of the parent alkanol and alkanoic acid
What’s examples of saturated hydrocarbons? (2)
Alkanes and cycloalkanes
What does saturated mean?
Contains only carbon to carbon SINGLE covalent bonds
What’s an example of an unsaturated hydrocarbon?
Alkene
What’s an unsaturated hydrocarbon?
Contains at least one carbon to carbon DOUBLE covalent bond
What solution can be used to distinguish an unsaturated hydrocarbon from a saturated hydrocarbon?
Bromine solution
What reaction forms an alkane
An alkene reacting with a hydrogen
What are examples of addition reactions?
Alkene reacting with bromine, hydrogen and water
What does fractional distillation of crude oil yield?
More long-chain hydrocarbons than are useful for present day industrial purposes
What is cracking?
An industrial method for producing a mixture of smaller, more useful molecules, some which are unsaturated
What does the catalyst do?
Allows the reaction to take place at a lower temperature
What is used when carrying out cracking in a lab?
An aluminium oxide or silicate catalyst
What can ethanol ,for alcoholic drinks, be made by?
Fermentation of glucose derived from any fruit or vegetable
What does an enzyme in yeast act as?
A catalyst in fermentation
Is there a limit to the ethanol concentration of fermentation products?
Ye
What’s distillation?
A method of increasing the ethanol concentration or fermentation products in the manufacturing of ‘spirit’ drinks
What are the effects off taking excess alcoholic drinks?
It can have damaging effects in the mind and health
Why is ethanol made from other means than fermentation?
To meet market demands
How is industrial ethanol manufactured?
By the catalytic hydration of ethene
How can ethanol be converted to ethene?
By dehydration
What’s ethanol used for when it’s mixed with petrol?
Fuel for cars
Where is ethanol obtained from?
Sugar cane, a renewable source of energy
How are esters formed?
By the condensation reaction between a carboxylic acid and an alcohol
What happened in a condensation reaction?
The molecules join together by the reaction of the functional groups to make water
What’s an ester link formed by?
The reaction of a hydroxyl group with a carboxyl group
Where can the parent carboxylic acid and parent alcohol be obtained by?
Hydrolysis of an ester
Is the formation and hydrolysis of an ester reversible?
Yeas
How are synthetic materials made?
By the chemical industry
What are most plastics and synthetic fibres made from?
Chemicals derived from oil
What are examples of plastics? (8)
Polythene Polystyrene Perspex PVC Nylon Bakelite Formica Silicones
What are recently developed plastics? (2)
Kevlar, which is very strong
Poly(ethenol), which readily dissolves in water
What are the everyday uses of plastics related to?
Their properties
What are examples of synthetic fibres?
Polyesters: terylene, and nylon
What’s the recently developed degradable plastic?
Bipol
What are most plastics?
Non biodegradable and their low density and durability can cause environmental problems
What do some plastics do when being burned/smouldered?
Give off toxic fumes including carbon monoxide
What can the toxic gases given off during burning/smouldering be related to?
The elements present in the plastic
What are the two types of plastic?
Thermosetting
Thermoplastic
What’s thermosetting?
When a plastic cannot be reshaped from heat
What’s thermoplastic?
When a plastic CAN be reshaped from heat
What are plastics made up of?
Long chain molecules called polymers
What are polymer molecules made from?
Many small molecules called monomers
What are polymers made from?
Small unsaturated molecules produced by cracking by a process called addition polymerisation
How do small unsaturated molecules join together?
By the opening of the carbon to carbon double bond
What’s the name of the additional polymer related to?
The name of the monomer
What are condensation polymers made from?
Monikers with two functional groups per molecule
What’s an example of condensation polymers?
Polyesters
What can an amine be identified from
The functional group
What’s an example of condensation polymers?
Polyamides
What’s the amuse link formed by?
A reaction. If an amine group with a carboxyl group
What forms an important class of food made by plants?
Carbohydrates
What supplies the body with energy?
Carbohydrates
What are carbohydrates?
Compounds which contain carbon, hydrogen and oxygen with the hydrogen and oxygen ratio of 2:1
Why can carbohydrates be divided into?
Sugars and starches
What are examples of sugars? (4)
Glucose
Fructose
Maltose
Sucrose
What can sugars (except sucrose) be detected by?
The Benedict’s test
What distinguishes starch from other carbohydrates?
The iodine test
What are sugars?
Carbohydrates with small molecules
What is starch?
A natural condensation polymer made of many glucose molecules linked together
What do plants convert for storing energy?
Glucose into starch
What happens during digestion?
Starch is hydrolysed to glucose which is carried by the blood stream to cells (where respiration occurs)
How can starch be hydrolysed?
By acid and enzymes
When do body enzymes function best at? (Temp)
Body temperature (destroyed at higher temperatures)
What to proteins form?
An important class of food made by plants
What are proteins use in the animal body?
The major structural materials of animal tissue and are involved in the maintenance and regulation of life processes and include enzymes, many hormones, eg insulin & haemoglobin
What’s a protein?
Condensation polymers made of many amino acid molecules linked together
What’s the structure of a section of protein based on?
The constituent amino acids
What does the condensation of amino acids produce?
Peptide (amide) link
How is the peptide link formed?
By the reaction of an amine group with a carboxyl group
What builds up within the body?
Proteins specific to the body’s needs
When does enzyme hydrolysis of dietary proteins produce amino acids?
During digestion
What can natural fats and oils be classified according to?
Their origin as animal, vegetable, marine
What’s the lower melting points of oils compared to those of fats related to?
The higher u saturation of oil molecules
What does the conversion of oils into hardened fats involve?
The partial removal of unsaturation by addition of hydrogen
What are fats and oils examples of?
Esters
What do fats and oils in the diet supply the body with?
Energy an a more concentrated source of energy than carbohydrates
What does the hydrolysis of fats and oils produce?
Fatty acids and glycerol in the ratio 3:1 mole of glycerol
What are fatty acids?
Saturated or unsaturated straight chain carboxylic acids, usually with long chains of carbon atoms
Is there enough oxygen in the air for the test to be positive?
No
What is a solution?
Is A mixture formed when a solute dissolves in a solvent
What’s it called when a substance which dissolves in a liquid?
Soluble
What’s it called when a substance does not dissolves in a liquid?
Insoluble
What’s a saturated solution?
One in which no more substance can be dissolved
What’s a dilute solution?
It has a lower concentration of dissolved substance that a concentrated solution
How is a solution diluted?
Adding more solvent
What are symbols used to show?
The state of species
How can reactions be followed
By measuring changes in concentration, mass, volume of reactants and products
How can the average rate of reaction or stage in reaction be calculated?
From initial and final quantities and the time interval
What can the rates of reaction be affected by?
Changes in: concentration
Particle size
Temperature
What can the collision theory be used to explain?
The effects of concentration and surface area on reaction rates
What are catalysts?
Substances which speed up reactions and aren’t used up by the reactions
What can catalysts be classified as? (2)
Heterogeneous
Homogeneous
What do heterogeneous catalysts work by?
The absorption of reactant molecules
How can the surface activity of a catalyst be reduced?
By poisoning
What can impurities in the reactants result in?
Industrial catalysts having to be regenerated or renewed
What do catalytic converters do?
They are fitted to cars to catalyse the conversion of poisonous carbon monoxide and oxides of nitrogen to carbon dioxide and nitrogen
What do cars with catalytic converters only use and why? (Petrol)
Lead-free petrol to prevent poisoning of the catalyst
What do enzymes do?
Catalyse the chemical reactions which take place in living cells of plants and animals
What can atoms be held together by?
Bonds
What is the relative atomic mass of an element? (Type of number)
Rarely a whole number
What do most elements exist as?
A mixture of isotopes
What are isotopes?
Atoms with the same atomic number but different mass numbers
What can atoms be represented by?
Nuclide notation
What can be found from the atomic number and mass number?
Number of protons, neutrons and electrons
What is every element made up of?
Very small particles crammed atoms
What does the atom mass number equal?
The number of protons plus neutrons
What do elements with the same number of outer electrons have?
Similar chemical properties
What are the elements of the periodic table arranged in terms of? (2)
Their atomic number and chemical properties
