John asked in Science & MathematicsChemistry · 1 decade ago

What is the difference between volatile organic compounds (VOC) and Hydrocarbons?

In California the A.Q.M.D. requires internal combustion engine emissions tests. I have found test equipment that does hydrocarbons but does not mention VOC. The look the same to me. Are they?

3 Answers

  • Matt
    Lv 7
    1 decade ago
    Favorite Answer

    Not all hydrocarbons are VOCs and not all VOCs are hydrocarbons. Tetrachlroethylene (PCE) is Cl4C2, very volatile, no hydrogen. Long chain hydrocarbons, like motor oil, are not volatile. Fuel hydrocarbons in gasoline engines are VOCs.

  • John
    Lv 6
    1 decade ago

    Hydrocarbons are compounds of Carbon and Hydrogen only. They are often volatile but not necessarily so.Wax is a hydrocarbon which is not volatile.The ones tested for in car exhausts are the unburnt gases which tell you the engine is not burning the fuel efficiently and which pollute the environment.

    VOC can refer to any compound of carbon and many other elements (not just hydrogen) so is a much wider category.These are compounds with a significant vapour pressure at normal ambient temp. ie they evaporate (volatalise) at low temp. Examples would include Acetone, Alcohol, Ether, Carbon Tetrachloride, Carbon Disulphide and many more which are not hydrocarbons at all.

  • 4 years ago

    organic and organic compounds are compounds that comprise specifically or usually Carbon and Hydrogen and carbon can purely form 4 bonds whilst H purely a million. Inorganic compounds are individuals that contain any element from the periodic table and C can form extra advantageous than 4 bonds and H serves as abridging atom.

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