Chemistry Flashcards
What is a Homologous series
a group or organic molecules with the same functional group
what is a cycloalkene, (draw a diagram as well)
When alkenes are connected in a circle
Google for diagrams
What is a isomer?
When a element has the same molecular formula but have a different electron arrangement
What happens when a hydrocarbon increases? (4)
- there is a larger surface area
- a higher amount of intermolecular forces
- a higher amount of energy is required to break these bonds
- this results in higher melting/ boiling point
Draw 2 structural isomers for C6H14
/\/\/ or /
/\/
/
If confused look on google
A sigma bond happens in alkanes
Draw a sigma bond
Google it
Where can a sigma bond only happen?
On the “x” axis
A Pi bond ONLY happens in alkenes, draw a Pi bond
Google it
What is a geometric isomer?
Same structural formula but a different arrangement in space
What are the three types of geometric isomers?
- Symmetric and Asymmetric
- Cis and Trans
- Z and E isomers
Draw a symmetric isomer for Ethene?
google it
Draw a asymmetric isomer for Ethene?
google it
What is a Cis isomer?
When there are matching groups on the same side
-Makes a C shape`
What is a trans isomer?
When the matching group are on opposite sides of the double bond
What is a “Z” isomer?
like cis isomer, matching groups on the same side
What is a “E” isomer?
like trans isomer, groups on different sides
What is a halo-alkanes?
when a halogen is attached to an alkane
Draw the electrophilic addition of Bromine?
google it
What are the most useful types of hydrocarbons?
Short chain hydrocarbons
What are 2 uses for short chain hydrocarbons?
- fuel
- making polymers
What is the process called for breaking hydrocarbons?
cracking
What are the two methods for cracking called?
Catalytic cracking
Steam cracking
What is catalytic cracking process?
uses a temperature of approx 550c
uses a catalyst known as Zeolite which contains aluminium oxide and silicon oxide
What is the steam cracking process?
uses a high temperature of over 800c and no catalyst just steam
what is combustion important for ?
- transport
- electricity
- heating
What is the equation for combustion?
hydrocarbon + oxygen —> water + carbon dioxide
When and why are free radicals formed?
- because alkanes need a very reactive thing to break their covalent bonds
- they are formed when a covalent bond splits to return the electrons to their atoms
What is homolytic fission?
when a bond splits and creates a free radical
electrons move individually
needs uv or high temperature
Heterolytic fission?
creates a positive and negative bond
splits a bond
what are the 3 stages for a free radical mechanism?
initiation
propagation
termination
Describe the initiation phase in free radical mechanism?
give example with chlorine
the free radical is formed
(needs uv or 300c)
Cl2–> 2Cl.
Describe the propagation in free radical mechanism?
give example with chlorine
step that starts and end with a free radical
the product starts to be formed
CH4+Cl.—> .CH3+HCl
Describe the termination phase in a free radical mechanism?
give example with chlorine
steps in which two free radicals react
there are no radicals in the products
2Cl.—> Cl2
Draw a dash and wedge diagram for methene
google it
What is the bond angle for a tetrahedral shape?
109.5 degrees
What is the bond angle for a trigonal planar shape?
- degrees
What is the bond angle for a linear shape?
180 degrees
Describe the bond length and strength for a sigma bond?
strong, good overlap of orbitals
Describe the bond length and strength for a Pi bond?
weaker, less overlaps of orbitals
describe the bond length and strength for an alkane?
single bond = sigma bond so weaker and longer
Describe the bond length and strength for an alkene?
double bond= Sigma and Pi bond so it is stronger
Describe a Benzene bond?
fits between single and double bonds
sigma + 0.5 Pi between each carbone
What are the properties of alumina?
Ionic Hard- strong bonds, lots of energy High melting Point insulator when solid conductor when liquid
When an acid dissolves in water what ion does it produce?
H+ ions
When an alkali dissolves in water what ion does it produce?
OH- ions
Acid is a ? donor ?
proton (H+)
Base is a ? acceptor?
H+ acceptor
Acid is a ? acceptor?
OH- acceptor
is hydrochloric acid a acid/alkali/base?
acid
is sodium hydroxide a acid/alkali/base or alkali and base?
alkali and base