1. Molecular Compounds September 15th, 2011

2. Dihydrogen Monoxide • is called "hydroxylacid", the substance is the major component of acid rain. • contributes to the "greenhouse effect". • may cause severe burns. • is fatal if inhaled. • contributes to the erosion of our natural landscape. • accelerates corrosion and rusting of many metals. • may cause electrical failures and decreased effectiveness of automobile brakes. • has been found in excised tumors of terminal cancer patients.

3. Dihydrogen Monoxide cont’d Despite the danger, dihydrogen monoxide is often used: • as an industrial solvent and coolant. • in nuclear power plants. • in the production of Styrofoam. • as a fire retardant. • in many forms of cruel animal research. • in the distribution of pesticides. Even after washing, produce remains contaminated by this chemical. • as an additive in certain "junk-foods" and other food products.

4. Just kidding – it’s water. • http://en.wikipedia.org/wiki/Dihydrogen_monoxide_hoax

5. Molecular or Covalent Compounds • Usually composed of two or more different non-metals • Atoms share a pair of electrons • The shared electrons are attracted to the nuclei of both atoms • Since they’re sharing and not transferring, the atoms remain uncharged • Let’s look at a Lewis Dot of water to see what’s going on...

6. Molecules • Molecular compounds are made of individual molecules with a fixed ratio • Molecules are neutral particles composed of two or more atoms joined together by covalent bonds

7. Let’s look at some molecular/ covalent compounds... • Each group will be assigned a different molecular/covalent compound • You will have 10 minutes to figure out how this molecule bonds covalently! • On chart paper, draw what’s going on • Your group will explain the molecular/covalent compound to the class!

8. How do we name these? • Naming Binary Molecular Compounds • *Remember! Binary means 2* • Let’s name CO2

9. More naming practice • NO2 is nitrogen dioxide • What about N2O4? Is it the same as NO2? • Answer – NO!

10. We don’t simplify the subscripts for molecular/covalent because since molecules are separate particles, (not a solid crystalline structure like ionic bonds), different formulas represent different molecules!

11. Naming a Binary Molecular Compound

12. Back in your groups! • Name your compounds!

13. Writing Chemical Formulas for Binary Molecular Compounds

14. Practice! • Write the chemical formula for dinitrogenpentoxide • Name the following molecular compounds • CO • PCl5