Unit 2 - Nature's Chemistry Flashcards
What is crude oil?
It is 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 components (things that make up) of the fractions
What is a fraction?
A group of hydrocarbons with boiling points in a given range
Ease of evaporation, boiling point range, viscosity and flammability are related to what of the molecules within the fractions?
The molecular size of the molecules within each fraction
Alkanes and alkenes are a subset series of hydrocarbons. How would you identify each?
Alkanes have an “-ane” ending and have no carbon to carbon double bonds,
Alkenes have an “-ene” ending and have a carbon to carbon double bond
Are alkanes saturated or not?
They are saturated
Are alkenes saturated or not?
Alkenes are not saturated. This is because they have a carbon to carbon double bond
How can alkenes be converted to alkanes?
Alkenes can undergo addition reactions that convert them into alkanes
What can be used to distinguish an unsaturated alkene from a saturated alkane?
Bromine solution
How is ethanol manufactured in industry to meet market demands?
By the catalytic hydration of ethane (an alkene)
What is a homologous series?
A homologous series is a set of compounds with the same general formula, similar chemical properties, have similar structural formula and show trends in their physical properties
What are isomers?
Isomers are compounds with the same molecular formula but a different structural formula e.g. alkenes and cycloalkanes
Chemical formula for cyclohexane?
C6H12
What is cracking?
Cracking is an industrial method for producing a mixture of smaller, more useful molecules, some of which are alkenes from crude oil. This is different to fractional distillation of crude oil which produces more long-chained hydrocarbons which aren’t as useful in industrial settings
There is a catalyst involved in cracking that allows it to be carried out at a lower temperature. What is the name of the two catalysts that can be used to carry out cracking in the laboratory?
Aluminium oxide or silicate catalyst
Carbohydrates are a useful source of energy for the body. An example of a good source of carbohydrates is plants. What elements make up carbohydrates?
Carbon
Hydrogen
Oxygen
Hydrogen and oxygen are in the ratio of 2H:1O
What can carbohydrates be sub-divided into category-wise?
Sugars and starches
Examples of sugars include glucose, fructose, maltose and sucrose (table sugar). What test can be used to detect most sugars? What sugar is the exception?
Benedict’s test. Sucrose is the exception and can’t be detected by this test
How can starch be distinguished from other carbohydrates?
Iodine test
What is starch?
Starch is a natural condensation polymer made up of many glucose molecules linked together
What do plants convert glucose to for storage?
Starch. (Makes sense since starch is made of many glucose molecules linked together)
What happens to starch during digestion?
Starch is hydrolysed into glucose which is carried by the blood stream to the cells of the body
What can hydrolyse starch?
Acids and enzymes. E.g. the acid and enzymes found in the stomach
What temperature do the enzymes of the body work best at?
Body temperature
