posted by Lauren on .
A sample of natural gas is 80.0% CH4 and 20.0% C2H6 by mass. What is the heat from the combustion of 1.00 g of this mixture? Assume the products are CO2 and H2O.
CH4 = -74.87 and C2H6 = -84.68
The delta Hs you have listed. Is that per mol or per gram? And the unit is J or kJ?
Write balanced equations for the combustion of each gas.
0.800 x 1.00 x delta H CH4 = ??
0.200 x 1.00 x delta H C2H6 = xx
?? + xx = total for mixture.
Note: If delta H is J or kJ/g the above is ok. If delta H is J or kJ/mol, you must first change the 1.00 g to mols for each gas. When you write the equation, adjust the delta Hs you have to account for the number of mols of CH4 or C2H6 if the corefficient isn't 1.