1. September 15 th, 2011

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

3. 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.  http://en.wikipedia.org/wiki/Dihydrogen_mo noxide_hoax http://en.wikipedia.org/wiki/Dihydrogen_mo noxide_hoax

5.  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.  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.  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.  Naming Binary Molecular Compounds  *Remember! Binary means 2*  Let’s name CO 2 PrefixNumberPrefixNumber Mono-1Penta-5 Di-2Hexa-6 Tri-3Hepta-7 Tetra-4Octa-8

9.  NO 2 is nitrogen dioxide  What about N 2 O 4 ? Is it the same as NO 2 ?  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. StepExample – N 2 O 4 1. Count the number of atoms of the first element in the chemical formula. Number of nitrogen atoms: 2 2. Write the appropriate prefix followed by the name of the element. Note that the prefix mono- is never used for the first element. First part of the name: dinitrogen 3. Count the number of atoms of the second element in the chemical formula. Number of oxygen atoms: 4 4. Write the appropriate prefix followed by the name of the element using the suffix – ide. If the prefix ends with a or o, this letter is dropped before the oxide. Second part of the name: tetroxide Full name: dinitrogen tetroxide

12.  Name your compounds!

13. StepsPhosphorus Trichloride (used to make insecticide) 1. Write the chemical symbol of the first element. First element in formula : P 2. Figure out how many atoms you need based on the prefix (mono-, di-, etc.) If there is no prefix, there is just one! Number of phosphorus atoms: 1 3. Write the chemical symbol of the second element. Second element in formula: Cl 4. Figure out how many atoms you need, based on prefix. Number of chlorine atoms: 3 5. Write the formula using the subscripts Formula: PCl 3

14.  Write the chemical formula for dinitrogen pentoxide  Name the following molecular compounds  CO  PCl 5