Question

Gaseous methane CH 4 will react with gaseous oxygen O 2 to produce gaseous carbon dioxide CO 2 and gaseous water H 2 O . Suppose 4.65 g of methane is mixed with 10. g of oxygen. Calculate the minimum mass of methane that could be left over by the chemical reaction. Round your answer to 2 significant digits.

Answer 1

Number of moles of methane= amount of methane/ mw of methane gram/mole=  4.65 g /16 g/mole = 0.291 moles

Number of moles of oxygen = amount of oxygen/mw of gram/mole= 10 g /32 g/mole = 0.313 moles

  

CH4(g) + 2O2(g) = CO2 (g) + 2H2O(g)

INITIAL MOLES    0.291 0.313 0 0

DELTA MOLES -0.1565 -0.313 0.1565   0.313

FINAL MOLES    ( 0.291 -0.1565 ) 0 0.1565   0.313

Number of moles of unreacted methane=   ( 0.291 -0.1565 ) moles = 0.1345 moles

Minimum mass of methane ureacted = number of moles of un reacted methane X mw of methane

= 0.1345 mole X 16 gram/mole = 2.2 gram