Aim: How are coordinate covalent bonds different than regular covalent bonds? Do Now: 1.Take out a calculator and reference tables. 2.Draw a dot diagram for the following molecules: MgCl 2 H 2 O NH 3

Answers to the do now MgCl 2 H 2 O NH 3

What type of bond do those compounds have? MgCl 2 H 2 O NH 3 What happens to electrons in a covalent bond? In a covalent bond, the atoms involved share electrons. Example: H 2 O

A new type of bond… Coordinate covalent bonds – a pair of shared electrons is supplied by a single atom. Example: The H + ion is a particle that can accept a pair of electrons (remember that H + is basically a proton). It can join a water molecule to form H 3 O +. This is called a hydronium ion. It can be written as shown above or H + (aq). Let’s draw the dot diagram.

Another Example NH 3 – Let’s draw the dot diagram. If NH 3 accepts a H + what does it become? Let’s draw the dot diagram.

How can we tell which bond is the coordinate covalent bond? You can’t. Once the coordinate covalent bond is formed, it is indistinguishable from an ordinary covalent bond. What is the result? Now, you have a polyatomic ion with a positive or negative charge. Most polyatomic ions contain coordinate covalent bonds. Where can we find a list? Reference Table E

Activity Textbook page 400 – Copy and Answer Questions 18-24

Homework #