Plz.help!!?
what volume of gas was absorbed by the alkali?
A)15cm^3
B)20cm^3
C)30cm^3
D)40cm^3
Answer:
Methane and ethane are hydrocarbons that are burned completely in oxygen to CO2 + H2O.
CH4 + 2O2 ===> CO2 + 2H2O
2C2H6 +7O2 ===> 4CO2 + 6H2O
The CO2 is absorbed by KOH because 2KOH + CO2 ===> K2CO3 + H2O.
The problem involves Avogadro's principle, that equal volumes of gases contain equal numbers of molecules. So ignoring the O2 and H2O,
CH4 ===> CO2, and
C2H6 ===> 2CO2
That means that the 10 cu cm CH4 ===> 10 cu cm CO2. Too, 10 cu cm C2H6 ===> 20 cu cm CO2. And 10 + 20 = 30 cu cm, so C).
"Fortitude," who answered above, is completely correct. The person who composed the question didn't consider that KOH also absorbs H2O as well as CO2.
Wow this is a hard quistion but im thinking it is B 20 cm^3
30 should be left over as carbon dioxide,
and 50 should have been absorbed as water.
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