Intermediate Bonding And Bond Polarity Flashcards
How do different atoms affect the position of electrons in a bond?
The attraction of the nuclei are different
They are attracted more to the more electronegative atoms
What are the three trends in electronegativity?
Nonmetals have higher electronegativities than metals
Electronegativity increases across a period
Electronegativity increases down a group
Why don’t noble gases have a value on the Pauling scale?
They rarely form covalent bonds
How can you calculate to what degree a bond is ionic and what degree it is covalent?
Comparing the difference in electronegativity between the two atoms in the bond
The percentage of covalent and ionic character is given on a table
What causes a covalent bond to be polar? Why?
If there is a greater difference in electronegativity is
For example in hydrogen chloride, the chlorine atom attract the electrons more strongly and the ends of the molecule will result in a small charge
Why are some molecules polar?
The structure of the molecules are not symmetrical
Some molecules contain polar bonds yet are not polar as the dipoles cancel each other out
Why are some liquids deflected by a charged rod? Give examples
Deflected – water
Not deflected – cyclohexane
Water has an overall dipole
What molecules are likely to be polar?
Linear molecules
Molecules with a single hydrogen
Molecules within an OH one end
Molecules with an N at one end
To molecules are likely to be nonpolar?
All elements
Most carbon compounds
What are dipole dipole interactions?
Permanent dipoles in polar molecules calls these interactions where the negative end of one molecule is attracted towards the positive end of another
What are London forces?
Instantaneous dipole is that produced when there are more molecules at one side of the atom then the other
This will induced dipole the neighbouring atoms as they will experience an electric field
Where do you London forces exist?
Between all atoms
The only intermolecular force that exists between noble gas atoms when the gases condense at low temperatures
Where is the position of the pair of electrons in a hydrogen molecule?
Equally between the nuclei as they experience the same force of attraction from each nucleus
Define electronegativity
The ability (of an atom)
to attract/to pull/to draw the electrons (1)
in/of a covalent bond
