Question

suppose 2.8 moles of methane are allowed to react with 3 moles of oxygen -- what is the limiting regent and how many moles of CO2can be made --how many grams of CO2

Answer 1

Given,

Moles of CH4 = 2.8

Moles of O2 = 3

The reaction between CH4 and O2 is as follows,

CH4 + 2O2 ------> CO2 + 2H2O

From the stoichiometry of the above reaction, we see that 1 mole of CH4 reacts with 2 moles of O2

Therefore 3 moles of O2 will react completely with 3/2 = 1.5 moles of CH4.

After 3 moles of O2 reacts with 1.5 moles of CH4, no more O2 is left to react (but CH4 is still left over)

Hence, Oxygen is the limiting reagent

2 moles of O2 reacts to produce 1 mole of CO2

=> 3 moles of O2 reacts to produce 1.5 moles of CO2

=> Moles of CO2 produced = 1.5

Molar Mass of CO2 = 44

=> Mass of CO2 produced = 1.5 x 44 = 66 g