3. Most refrigerants utilize the energy involved in the liquid/gas phase change of a molecule, where an ideal refrigerant is noncorrosive, nonflammable, and has a boiling point around the desired temperature. Many fluorinated carbons meet all of these requirements, but the extremely high stability of some (such as CFCs) caused them to be phased out by the Montreal Protocol due to their ozone depleting potential. 3.a. R-12 (CCl2F2) was commonly used in household refrigerators and vehicle air conditioners prior to 1994. What is the correct Lewis structure for R-12

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Explanation:

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relative humidity is a measure of the amount of moisture in the air relative to the total amount of moisture the air can hold.

so d

the grams   of   barium that   are in   2.3 x 10^23   atoms of barium   is   52.4 g (answer c)

    calculation

mass = moles   of ba   x molar   mass of ba

  molar mass of ba from periodic table=   137.3 g/mol

  use the   avogadro's law   constant   to   calculate the moles of barium

  that   is     1 mole =   6.02   x 10^23 atoms

                    ? moles = 2.3 x 10^23   atoms

by cross   multiplication

=(1 mole   x 2.3x 10^23 atoms)   / 6.02   x10^23 atoms)=   0.382   moles

mass   is therefore = 137.3   g/mol x 0.382 mol = 52.4 ( answer c)

explanation: