Electronegativity and Polarity Flashcards

1
Q

Define electronegativity.

A

The attraction of a bonded atom for the pair of electrons in a covalent bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the most electronegative element?

A

Flourine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the difference between a polar bond and a non polar bond?

A
  • A polar bond is when the bonded electron pair is shared unequally between the bonded atoms as a result of different electronegativities, this is a permanent dipole
  • A pure covalent bond is when the bonded electron pair is shared equally between the bonded atoms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a polar molecule?

A
  • When the molecule is unsymmetrical and the dipoles do not cancel out
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Are CO2 and H20 polar molecules?

A

Co2 = dipoles cancel, non polar
H20 = dipoles do not cancel, polar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are three types of intermolecular forces?

A
  • Induced dipole - dipole interactions (london forces)
  • Permanent dipole - dipole interactions
  • Hydrogen bonding
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How are induced dipole - dipole interactions formed?

A
  • there is movement of electrons that produce a changing dipole in a molecule
  • at any moment, there is an instantaneous dipole
  • the instantaneous dipole induces a dipole on a neighbouring molecule
  • The induced dipole induces further molecules which attract one another
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does the strength of induced dipole - dipole interactions vary?

A
  • The more electrons
  • The larger the instantaneous and induced dipoles
  • The greater the induced dipole - dipole interactions
  • The stronger the attractive forces between molecules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the trend with the number of electrons and boiling point?

A
  • The more electrons, the greater the strength of the london forces and therefore the more energy required to overcome the london forces
  • This increases boiling points
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a simple molecular lattice?

A
  • Molecules are held by weak intermolecular forces
  • the atoms within each molecule are held by strong covalent bonds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the properties of simple molecular lattices?

A
  • Low melting point and boiling point due to weak london forces
    -Soluble in non - polar solvents
  • Can not conduct electricity as there are no mobile electrons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly