Section 4.2 Molecular Compounds

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Section 4.2 Molecular Compounds. RECALL. Ionic Compounds: consist of positive and negative ions, formed by the transfer of electrons from a metal to a non-metal are electrolytes (conduct electricity when dissolved in water). MOLECULAR COMPOUNDS. - PowerPoint PPT Presentation

Transcript of Section 4.2 Molecular Compounds

  • Section 4.2 Molecular Compounds

  • RECALLIonic Compounds:

    consist of positive and negative ions, formed by the transfer of electrons from a metal to a non-metal

    are electrolytes (conduct electricity when dissolved in water)

  • MOLECULAR COMPOUNDSform when two non-metal atoms share electrons

    the bond formed by the SHARING of electrons is called covalent bond

    are non-electrolytes (do not conduct electricity when dissolved in water)

  • Diatomic MoleculesDiatomic molecules made of two atoms

    Hydrogen H2 (gas)Nitrogen N2 (gas) Fluorine F2 (gas)Oxygen O2 (gas)IodineI2 (solid)ChlorineCl2 (gas)BromineBr2 (liquid)

    HaveNoFear OfIceColdBeer

  • the shared electrons spend part of their time with one hydrogen nucleus and part of their time with the other nucleusNOTE: one electron must come from each partner in the arrangement so that a PAIR is sharedLOSING an electron will leave H with no electronsConsider two atoms of hydrogen

  • CARBON AND OXYGENLewis Dot Diagrams

  • CARBON AND OXYGENCarbon has four electrons to shareOxygen has two electrons to share

  • CARBON AND OXYGENthese pairs are shared between the atoms

  • Valence MethodYou can reach the same conclusion using the valence method used for ionic compounds C4+ O2-C2 O4CO2Write the symbolsWrite the valence above the atomsCriss-cross and reduce (if necessary)Write out the formula* doesnt always work for molecular compounds

  • Naming Molecular CompoundsUse Greek prefixes to indicate the number of each type of atom in the compoundGREEK PREFIXES

    mono6. hexa2. di7. hepta3. tri8. octa4. tetra9. nano5. penta10. deca

  • Naming Molecular CompoundsSOME RULES

    use the Greek prefixes to represent the subscript in the final formula

    mono is dropped if it applies to the first element listed

    the ending of the second element is changed to -ide

  • Naming Molecular CompoundsCO2monocarbon dioxidedroppedcarbon dioxideCOcarbon monoxideCOsilicon tetrachlorideSiCl4Nl3nitrogen triiodide

  • Ban Dihydrogen MonoxideThe Invisible KillerDihydrogen monoxide is colorless, odorless, tasteless, and kills uncounted thousands of people every year. Most of these deaths are caused by accidental inhalation of DHMO, but the dangers of dihydrogen monoxide do not end there. Prolonged exposure to its solid form causes severe tissue damage. Symptoms of DHMO ingestion can include excessive sweating and urination, and possibly a bloated feeling, nausea, vomiting and body electrolyte imbalance. For those who have become dependent, DHMO withdrawal means certain death.

  • Dihydrogen monoxide:

    is also known as hydroxyl acid, and is the major component of acid rain. contributes to the "greenhouse effect." may cause severe burns. 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.

  • Contamination Is Reaching Epidemic Proportions!

    Quantities of dihydrogen monoxide have been found in almost every stream, lake, and reservoir in America today. But the pollution is global, and the contaminant has even been found in Antarctic ice. DHMO has caused millions of dollars of property damage in the midwest, and recently California.

  • Despite the danger, dihydrogen monoxide isoften 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.

  • The Horror Must Be Stopped!

    The American government has refused to ban the production, distribution, or use of this damaging chemical due to its "importance to the economic health of this nation." In fact, the navy and other military organizations are conducting experiments with DHMO, and designing multi-billion dollar devices to control and utilize it during warfare situations. Hundreds of military research facilities receive tons of it through a highly sophisticated underground distribution network. Many store large quantities for later use.

  • Act NOW to prevent further contamination!

    Find out more about this dangerous chemical.

    What you don't know can hurt you and othersthroughout the world.

    How many people would like to sign a petition toban dihydrogen monoxide?

  • HomeworkRead p. 152- 158Complete Q. 1-4 (p.156)Molecular Compounds WS#11