Given the reaction: CH4 (g) + 2 O2 (g)  CO2 (g) + 2H2O (g) How many moles of oxygen are needed for the complete combustion of 3.0 moles of CH4 (g) ?

For the complete combustion of 3.0 moles CH4 we need 6.0 moles O2

Explanation:

Step 1: Data given

Number of moles of CH4 = 3.0 moles

Step 2: The balanced equation

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

Step 3: Calculate moles of O2

For 1 mol CH4 we need 2 moles of O2 to produce 1 mol of CO2 and 2 moles of H2O

For 3.0 moles CH4 we need 2 * 3.0 = 6.0 moles of O2

To produce 3.0 moles of CO2 and 6.0 moles H2O

For the complete combustion of 3.0 moles CH4 we need 6.0 moles O2