Lesson 2: Covalent Compounds

How many single covalent bond does the following make: Hydrogen Carbon Nitrogen Oxygen Fluorine

1 4 3 2 1

How many single covalent bonds does the following make: Arsenic Selenium Bromine Iodine

3 2 1 1

How many single covalent bonds does the following make: Silicon Phosphorus Sulfur Chlorine Geranium

4 3 2 1 4

Dispersion Forces (AKA london forces)

A intermolecular force that has a weak attractive force that play a part in ALL covalent molecules, both polar and non-polar.

Which compound do you think has the highest bp? a. CH3OH b. CH4 c. CH3F

A. CH3OH has the highest boiling point because it is a hydrogen bond.

Hydrogen Bonding

An intermolecular force that is extremely strong form of dipole force -ONLY at play in molecules which contain -N-H, -O-H, or F-H

which of the following is a better definition of hydrogen bonding? a. A bond between a hydrogen atom and a nitrogen atom, a bond between a hydrogen atom and an oxygen atom, or a bond between a hydrogen atom and a fluorine atom b. a N-H group, an OH group, or a F-H group c. A very strong intermolecular attraction between molecules that contain N-H groups, O-H groups, or F-H groups

C. A very strong intermolecular attraction between molecules that contain N-H groups, O-H groups, or F-H groups

Would a compound between potassium and sulfur be ionic or covalent?

Ionic

Do you think Lithium is likely to be found in a covalent compound? Why or why not?

No because it is a metal and covalent bonds are only formed with non-metals

What is the formula for phosphorus and hydrogen?

PH3

What does the number of dots shown in the electron dot structure tell you about an atom?

The dots in the electron dot structure show the number of electrons in the outer valence shell.

How can you determine the number of covalent bonds an atom will form based in its electron dot structure?

The number of of bonds an atom can have depends on How many electrons the atom needs to satisfy the octet. (valence electrons-8)

Electronegativity

The tendency of an atom to pull shared electrons toward itself when that atom is sharing electrons with another atom -The electronegativity of atoms is measured on a scale of 0-4, with 0 being the least electronegative, and 4 being the most electronegativity -If two atoms are joined by a covalent bond, and the difference between the two atoms is 0.5 or greater we can consider that covalent bond to be polar.

How many electrons in the electron-dot structure for oxygen oxygen are unpaired?

There are 2 electrons on either side of the electron-dot structure of oxygen that are not paired

How many of the electrons in the electron-dot structure for oxygen are paired?

There are 2 pairs in oxygen's electron-dot structure.

How many chlorine atoms can you join to the carbon atom?

There would need to be 4 chlorine atoms to give carbon a full 8 outershell.

Dipole Forces

Weak intermolecular forces that result from the partial positive and partial negative charges that form on atoms in polar molecules. *Dipole forces are ONLY at play in polar molecules

Covalent Bonding

When atoms share electrons, binding the atoms together. -Do NOT contain ions ^contain non-metal elements -Only covalent compounds are made of molecules -Ionic compounds are NOT made of molecules, but of extended ionic crystals

Ionic Bonding

When ions with opposite charges are attracted to each other. -Ionic compounds contain ions. -Most ionic compounds contain both metal and non-metal elements.

How many fluorine atoms do you think could join to form a molecule?

You need 2 fluorine atoms to build a molecule, and because fluorine is a diatomic ion, they can bond with itself.