A source region must have certain temperature and humidity properties that can remain fixed for a substantial length of time to affect air masses above it. above it. Air mass source regions occur only in the high or low latitudes; middle latitudes are too variable.
Answer:
CH4 + 2 O2 --> CO2 + 2 H2O
Explanation:
CH4 + 2 O2 --> CO2 + 2 H2O is the only reaction where an element (oxygen) undergoes a change in oxidation state. In this reaction oxygen changes disproportionately to O⁻². That is ...
O₂ → CO₂ + 4e⁻ ==> oxidation
<u>O₂ + 4e⁻ → H₂O ==> reduction </u>
2O₂ + 4e⁻ → CO₂ + H₂O + 4e⁻ ==> Net oxidation-reduction
=> 4e⁻ gained by one mole O₂ in formation of CO₂ = 4e⁻ lost by the other mole O₂ in forming H₂O.
Then...
Including CH₄ (whose elements do not undergo changes in oxidation states) requires doubling reaction to balance by mass thus giving ...
2CH₄ + 2O₂ + 8e⁻ → 2CO₂ + 2H₂O + 8e⁻
Cancelling 8 reduction electrons on left with 8 oxidation electrons on right gives...
2CH₄ + 2O₂ → 2CO₂ + 2H₂O
When we convert the given mass in grams and volume in liters to m/v percent, we recall that m/v percent is expressed as grams/100 milliliters. In this case the expression becomes (50 grams/ 2500 L)*(0.1L/100ml), that is equal to 0.002 grams/ 100 mL. Hence the the concentration is equal to 0.2 m/v percent.
