posted by Jenny on .
Calculate the ratio of moles of CO2 produced to moles of the original gas mixture?
A mixture of methane (CH4) and ethane (C2H6) is stored in a container at 294 mmHg. The gases are burned in air to form CO2 and H2O. If the pressure of CO2 is 351 mmHg measures at the same temperature and volume as the original mixture, calculate the ratio of moles of CO2 produced to moles of the original gas mixture?
Can someone please help me solve this question. I've been trying to figure this out forever. Please show me step by step on how to solve this. I know we have to use the ideal gas law expression for both carbon dioxide and methane and ethane gas mixture. Any help is greatly appreciated!
well, the moles will be proportional to pressure.
Balance the equations:
CH4+2O2>>CO2 + 2H20 **1
C2H6+7.5 O2>> 2CO2 + 3H2O **2
so in methane, one gets the same amount of CO2 as CH4
In the ethane, one gets twice as much.
So,of the final pressure, the difference is one of the CO2 from the ethane, which is the same amount as the 1/2 the original ethane.
Pressure(351-294)mmHg. Then the pressure due to the other 1/2 of ethane reaction is the same.
Now we can examine the mole ratio:
partial pressure CO2 due to ethane= 2(351-294)=114mmHg
partial pressure CO2 due to methane=357-114= 243mmHg
so moles methane/ethane= 243/114
check my thinking.