To6 B Flashcards
(11 cards)
What are the physical properties of a halogenalkanes
Ethereal smell
Insoluble in water
Boiling point increase down the group
What makes a halogenalkane primary secondary or tertiary
Primary - the carbon bonded to the halogen is bonded to one carbon
Tertiary - the carbon bonded to the halogen is bonded to two carbons
Tertiary- the carbon bonded to the halogen is bonded to three carbons Tertiary
Why are halogenalkanes insoluble in water
Between water molecules there are hydrogen bonds
In halogenalkanes there are permanent dipole permanent dipole bonds
The halogenalkanes have weaker intermolecular forces therefore it is not energetically favourable for them to mix
Why do halogenalkane’s boiling point increase down the group
The atomic number increase
More electrons present
Therefore more London forces
Therefore more energy required to overcome the more London forces
What is a nucleophile
A molecule or substance that has the tendancy to donate electrons
What is the general formula for a halogenoalkanes
CnH2n+1 X
How is a halogen shown in a halogenoalkane
X
How are halogenoalkanes produced from an alkane
Free radical substitution of alkane
What makes halogenoalkanes reactive
Hydrocarbons only contain hydrogen and carbon which have similar electronegativities so their bonds are almost non-polar
Halogenoalkanes contain a halogen atom with an electronegativity higher than carbon so the C-X bond is polar
Explain the trend in reactivity of halogenoalkanes down group seven
The reactivity decreases down the group
The electronegativity decreases down the group making the C-X bond less polar
How do polarised bonds form in halogenalkanes
Carbon is less electronegative than halogen
The bond forms a dipole
The carbon is left with a positive charge which means a neutrophil can attack it
