Covalent Bonds

Vocab

100

This type of bond occurs when electrons are shared

covalent bond

200

This is another name for the pairs of electrons which are UNSHARED (don't participate in bonding)

lone pairs

300

What does binary mean?

Contains only 2 different elements

400

What is resonance?

Occurs when more than one valid Lewis structures can be written for a molecule or ion.

500

What is electronegativity?

the relative ability of an atom to attract electrons in a chemical bond

Naming

100

PCl3

phosphorus trichloride

200

Cl2O7

dichlorine heptoxide

300

P4O6

tetraphosphorus hexoxide

400

HClO3

chloric acid

500

HI

hydroiodic acid or hydriodic acid

Formulas

100

Write the formula for: disulfur trioxide

S2O3

200

Write the formula for: dinitrogen monoxide

N2O

300

Write the formula for: hydrofluoric acid

HF

400

What's the difference between a binary acid and an oxyacid?

Binary acids are made of hydrogen and one other element. Oxyacids include hydrogen, at least one other element and oxygen.

500

Write the formula for chloric acid. DOUBLE JEOPARDY: you can risk as many points as you want (up to 10 if you have less than ten): if you get the answer correct--you get that many points, if you get it wrong, the other team gets the points you risked

HClO3 Double jeopardy: write the formula for chlorous acid

Molecular Structures

100

Why can hydrogen never be the central atom?

It can only share one pair of electrons--therefore, it can only be connected to one other atom

200

How do you determine the central atom?

The one with the lowest number of atoms; the one with the lowest electron affinity (typically further left on the periodic table)

300

Draw the lewis structure for NF3

N is central atom--3 single bond F on each side; lone pair of electrons around central atom

400

Write the structure for CS2

Carbon is central atom; double bonded to sulfur on each side; each sulfur atom has 2 lone pairs of electrons

500

PCl5

Phosphorus is central atom; 5 chlorine around central atom for expanded octet

Electronegativity and Polarity

100

How is a polar covalent bond different than a non-polar covalent bond?

Polar covalent bonds result from unequal sharing of electrons; in non-polar covalent bond, electrons are shared equally.

200

Give an example of a pure, non-polar covalent bond:

O2, N2, F2--anything that's bonded to itself

300

What is the electronegativity difference to be considered covalent?

Less than 1.70

400

Polar or Non-polar: ClF

polar

500

Explain if CS2 is polar or nonpolar and why?

non-polar; charges are balanced; no lone pairs around entral atom