Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Unit 1: Chemistry > Lesson 3: Bonding and Electronegativity > Flashcards

Lesson 3: Bonding and Electronegativity Flashcards

Hydrocarbons, electronegativity and polarity.

You may prefer our related Brainscape-certified flashcards:
AP® Chemistry flashcards Periodic Table flashcards Chemistry 101 flashcards Organic Chemistry 101 flashcards
1
Q

Organic Compounds

Description

A

A covalent compound that contains one or more carbon chain.

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

Organic Compounds: Hydrocarbons

Bond Length and Strength

A
  • The more carbon bonds there are, the longer the chain.
  • The longer the chain, the more energy required to break the bonds.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Organic Compounds: Hydrocarbons

Properties

Long chains

A
  • Higher boiling point.
  • High volatility.
  • High viscosity.
  • Low flammability.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Organic Compounds: Hydrocarbons

High Boiling Point

Property

A
  • Property of long chain hydrocarbons.
  • Requires a lot of energy to break the bonds between carbon atoms.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Organic Compounds: Hydrocarbons

Low Volatility

Property

A
  • The high boiling point means the hydrocarbon has low volatility.
  • Volatility is the tendency to turn into a gas.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Organic Compounds: Hydrocarbons

Viscosity

Property

A
  • Long chains are likely to get tangled.
  • This causes the substance to ‘clump together’ and flow slowly.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Organic Compounds: Hydrocarbons

Flammability

Property

A
  • Larger chains don’t vapourise easily (low volatility).
  • Ignition is much more effective if the hydrocarbon and oxygen are mixed together as gas.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Metallic Bonding

Description

A
  • Electrons on the highest energy level of a metal atom become delocalised.
  • Creates a sea of delocalised electrons and layers of positive ions.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Bonding and Electronegativity

Description

A
  • The tendency of an atom to attract a bonding pair of electrons.
  • Atoms with similar electronegativity for covalent bonds.
  • Those with different electronegativity form ionic bonds.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Electronegativity and Polarity

Factors Affecting Electronegativity

A
  • Atomic charge.
  • Distance from the nucleus.
  • Electron shielding.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Electronegativity and Polarity

Electron Shielding

Factors of Electronegativity

A
  • Core electrons repelling outer electrons.
  • This reduces the effect of the charge of the nucleus.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Electronegativity and Polarity

Atomic Charge

Factors of Electronegativity

A
  • The greater the charge of the nucleus, the stronger the attraction of electrons.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Electronegativity and Polarity

Distance from Nucleus

Factors of Electronegativity

A
  • Outer shell electrons are further from the nucleus.
  • The ‘pull’ of the nucleus on those electrons is weaker because there is a greater distance and more electron shielding.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Electronegativity and Polarity

Differences in Electronegativity

A
  • The more electronegative atom will have a greater share of electrons.
  • Eg. Cl is more electronegative than H, so in HCl the electrons are pulled towards Chlorine.
  • This is called a dipole, when each end of a bond has a different charge.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Electronegativity and Polarity

Differences in Electronegativity

Summary

A
  • No difference: non-polar covalent bond.
  • Small difference: polar covalent bond.
  • Large difference: ionic bond.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Electronegativity and Polarity

Dipoles and Polarity

A
  • Dipoles represent differences in electronegativity.
  • If there is a difference, the molecule is polar.
  • Water is a polar molecule.
17
Q

Electronegativity and Polarity

Bonding in Identical Atoms

A
  • In a covalent bond, electrons are shared.
  • When two atoms are identical, electrons are shared equally.
  • This is because they have the same electronegativity.
18
Q

Electronegativity and Polarity

Charge Difference

A
  • The charge difference between H and Cl is called a permanent dipole.
  • HCl is non-symmetrical (polar) and therefore a polar covalent bond.
19
Q

Electronegativity and Polarity

Non-polar Molecules

A
  • Symmetrical molecules are non-polar even though they contain polar bonds.
  • Eg. C-Cl4: 4 dipoles acting in opposite directions cancel each other out.
20
Q

Electronegativity and Polarity

Shape and Polarity

A
  • CH3Cl is a polar molecule as the polarity of the C-Cl bond is not cancelled out.
  • in CCl4 the C-Cl bonds cancell each other out as the molecule is symmetrical.
21
Q

Electronegativity and Polarity

Solubility

A
  • Solubility depends on polarity.
  • If the molecule contains polar bonds it will dissolve well in polar solvents.
  • If the molecule is non-polar it will likely dissolve in non-polar solvants.

Unit 1: Chemistry (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions