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53 Cards in this Set
- Front
- Back
What is a homologous series?
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A homologous series is a family of compounds with similar chemical properties |
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What is a functional group
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It is part of the organic molecule that is largely responsible for the molecules chemical properties |
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What is the molecular formula
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It shows the number and type of atoms of each element present in a molecule (It does not show how they are joined together) |
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What is the empirical formula |
is the simplest whole number ratio of the atoms of each element present in a compound |
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What is the general formula
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Is the simplest algebraic formula to generate the molecular formula
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What is the general formula for alkanes
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CnH2n+2
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What is the general formula for alkenes |
CnH2n
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What is the general formula for alcohols |
CnH2n+1OH |
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What is the general formula for Carboxylic acid |
CnH2nO2
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What is the general formula for a keytone |
CnH2nO
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`What is the displayed formula |
It shows the relative positioning of all of the atoms in a molecule and the bonds between them
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What is the structural formula
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it uses the smallest amount of detail necessary to show the arrangement of the atoms in a molecule |
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What is Structural isomerism |
Compounds with the same molecular formulae but different structural formulae
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What is homolytic fission
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When a covalent bond breaks each of the bonded atoms takes one of the shared pair of electrons takes one of the electrons
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What is heterolytic fission
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When a covalent bond breaks one of the bonded atoms takes both of the electrons from the bond.
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What is an addition reaction
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It is two reactants joining together to form one product |
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What is a substitution reaction |
One group of atoms are replaced by a different atom or group of atoms |
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What is a elimination reaction |
Is the removal of a small molecule from a larger one. One reactant will form two products |
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What is a sigma bond |
It is when each atom in a alkane is joined to four other atoms by single covalent bonds
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Why can crude oil can go though fractional distillation |
Because the boiling of the many alkanes in crude oil are different increasing with length
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How does chain length effect boiling point
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London forces act between molecules that are in close surface contact as the chain length increases so will boiling point
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Effect of branching on boiling point
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Branched molecules will have fewer surface points of contact between molecules meaning less London forces Also branches get in the way and prevent how close the molecules can be decreasing the effect of intermolecular forces |
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Why do alkanes lack reactivity
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C-C and C-H sigma bonds are strong C-C bonds are non - polar Electronegativity of C-H are too similar to be polar |
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Mechanisms for bromination of alkanes - Initiation
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Br2 + UV_light - Br•+•Br
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Mechanisms for bromination of alkanes - Propagation |
Propagation 1 - CH4 + Br· → ·CH3 + HBr Propagation 2 - ·CH3 + Br2 → CH3Br +Br· |
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Mechanisms for bromination of alkanes - Termination
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Br· + Br· → Br2 ·CH3 + ·CH3 → C2H6 ·CH3 + ·Br → CH3Br |
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Why is a pi bond formed In a double bond
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Formed by the overlapping of two P - orbitals one from each carbon atom of the double bond (Each carbon atom contributes one electron to the electron pair) |
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What is the bond angle around a double bond and explain why this is |
Because of the 3 regions of electron density they will all repel as much as possible so the bond angle is 120
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What is meant by the term unsaturated
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Alkenes are unsaturated because they can add a hydrogen when the C=C double bond is broken.
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What are the conditions to have E/Z isomerism |
A C==C double bond
Different groups attached to each carbon atom of the double bond |
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Which is weaker a sigma bond or a pi bond and explain why |
pi bond beacuse the electron density is concentrated above and below the plane so it is more exposed than sigma bonds so it can undergo additon reactions easily |
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What is an electrophile
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it is a atom or group of atoms that is attracted to an electron rich centre (The electrophiles tend to be positive ions or molecules that are partial positive) |
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Explain recycling in terms of environmental concerns
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Recycling polymers reduces their environmental by conserving fossil fuels as well as reduced waste going to the landfill Discarded polymers are sorted by type chopped, washed, dried and melted it is then cut into pellets and reused |
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Explain PVC recycling in terms of environmental concerns
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Disposal of PVC is hazardous due to the high chlorine content dumping In the landfill is not sustainable when burnt releases Hydrogen chloride Instead solvents dissolve the polymer and recovered by precipitation |
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Explain using waste polymers as fuel recycling in terms of environmental concerns
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Because it contains petroleum or natural gas they are harder to recycle They are incinerated to produce heat energy generating steam and turn a turbine producing electricity. |
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Explain Feedstock recycling in terms of environmental concerns
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are the chemical and thermal processes that can reclaim monomers gases or oils the raw products are then reused
An advantage of this is you can handle unsorted and unwashed polymers |
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Explain Biodegradable polymers in terms of environmental concern
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They are broken down by microorganisms into water and carbon dioxide (Usually made from Starch or cellulose or contain additives that alter structure so it can be broken down) |
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Explain Photodegradable in terms of environmental concerns
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Photodegradable oil based polymers these polymers contain bonds that are weakened by absorbing light or adding light absorbing additives
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What are the physical properties of alcohol |
alcohols contain a polar O--H bond because of electronegativity difference they are therefore polar they will have very weak London forces but strong hydrogen bonds between O--H |
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Explain why alcohols have a higher boiling point |
Because alcohols have stronger hydrogen bonds that require much more energy to overcome than weaker London forces
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Explain alcohols solubility in water |
Because of the polar O--H group it allows the compound to form hydrogen bonds with the water making them more water soluble |
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Molecular formula of dichromate |
Cr2O7
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What is a dehydration reaction
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A reaction in which a water molecule is removed |
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Explain the process of the dehydration of alcohols
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The alcohol is heated under reflux with an acid catalyst such as Sulphuric or phosphoric acid
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Alcohol is heated under reflux with sulphuric acid (catalyst) and a sodium halide
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What is a nucleophile |
An atom or group of molecules attracted to an electron deficient carbon atom it will donate a pair of electrons to form a new covalent bond
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Give 3 examples of nucleophiles |
:OH- , H2O: , :NH-3 CN -
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How would you measure the rate of hydrolysis of primary haloalkanes
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Carry out the reaction in the presences of aqueous silver nitrate as the reaction takes place halide ions are produced which will react with the silver nitrate forming a precipitate Ethanol is also presence allowing the haloalkanes and water to mix producing a single solution |
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Why were CFCs and HCFCS commonly used
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Because of how stable they both are due to the carbon-halogen bonds
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