The combustion of methane (CH4) produces carbon dioxide CO2 and water. a. Write
ID: 858250 • Letter: T
Question
The combustion of methane (CH4) produces carbon dioxide CO2 and water.
a. Write a balanced chemical equation for the combustion reaction.
b. Calculate the total pressure and the partial pressure of all the gases AFTER 20.0 g methane is reacted with 60.0 g of oxygen in a 20.0L container at 255 K. Assume all the WATER produced is a solid at this temperature and that it takes up negligible volume in the container. Assume ALL other substances are gases at this temperature.
Ptotal = ____________atm
PCH4 = ____________atm
PO2 = ____________atm
PCO2 = ___________atm
PH20 = _____________atm
Explanation / Answer
a)
CH4 + 2 O2 -------> CO2 + 2 H2O
represents the balanced reaction.
b)
20 grams methane (MW = 16 g/mol) reacts with 60 g oxygen (MW= 32 g/mol) to give products.
Moles methane = 1.25 and moles oxygen = 1.875 before reaction
So, left is 1.25 - 1.875/2 moles methane and 1.875/2 moles CO2
Total volume = 20 litres
Gas equation PV = nRT
So, Pco2 = nRT/V = 0.9375*0.0821*255/20 = 0.981 atm
Pmethane = (1.25-0.9375)RT/V = 0.327 atm
Ptotal = 1.308 atm
PCH4 = 0.327 atm
PO2 = 0 atm
PCO2 = 0.981 atm
PH20 = 0 atm