10. Alkanes/ Alkenes/ Alkanols Flashcards
What are the names of the alkanes from 1C to 8C atoms in molecules?
What is meant by a saturated hydrocarbon?
A hydrocarbon where all C-C bonds present are single
What is a “hydrocarbon”?
A compound containing only C and H atoms
What is the 3D shape of methane (CH4) ?
Tetrahedral
What is shown by a “Molecular Formula” ?
The types of atom and their relative abundance in a molecule. The abundance is shown as subscript
e.g
H2O
C3H8
NH3
CO2
What is shown in a “Full Structural Formula”?
All the atoms and all the bonds connecting them in a molecule
What is shown in a shortened structural formula?
Each C in the chain is shown with everything bonded to it (not other C atoms in chain) No bonds need to be shown , although C=C bonds are allowed
What is the general formula of the alkanes?
What are the 2 main reactions of alkanes?
- Combustion
- Catalytic cracking
Why is catalytic cracking an important reactions for longer chain alkanes?
- To produce shorter chain, more useful alkanes
- To obtain alkenes which are useful reactants to make other products
What are the products of alkane combustion?
CO2 and H2O
How do we test for the products of combustion of a hydrocarbon?
What is a “functional group”?
The part of a molecule which gives it its chemical (and physical) properties
What is the functional group in the alkenes?
The C=C bond
How can we obtain alkenes?
By catalytic cracking of loneger chain alkanes
What is the general formula of the alkenes?
Cn H2n
What is the general formula of the Alkanols?
Cn H2n+1 OH
What are the 2 ways to make ethanol?
What are some uses of ethanol?
Why is pure ethanol unable to conduct electricity?
It is a covalent molecule which doesn’t break down into ions
What is the functional group in Alkanols?
The hydroxyl group
Why are alkanols miscible with water
The hydroxyl group is polar
What are the 2 main reactions of alkenes?
- Addition (particularly with water to make alkanols)
- Polymerisation (to make plastics)
What is meant by a “raw material” ?
A substance readily available in the earth’s crust.
e.g
Sodium chloride
Water
crude oil
What happens in a “hydration “reaction?
A water molecule is added to a molecule with a C=C bond.
What happens in a “hydrogenation” reaction?
Hydrogen is added across a C=C bond
What happens in a “dehydration” reaction?
A water molecule is removed from an alkanol
What is the catlayst used in a dehydration reaction?
Hot aluminium oxide
What are the 2 reactions of alkanols?
- Combustion
- Dehydration
What is a Homologous Series?
Molecules with
- same general formula
- similar chemical properties
- gradation in physical properties
