Question

Given the following chemical reaction: 2 O2 + CH4 CO2 + 2 H2O What mass of oxygen is required to completely react with 20 grams of CH4? 6 C 12.01 Carbon 1 H 1.01 Hydrogen 8 O 16.00 Oxygen A. 10 grams O2 B. 20 grams O2 C. 80 grams O2 D. 144 grams O2

Answer 1

The chemical equation is:
CH₄ + 2O₂ → CO₂ + 2H₂O

First, we calculate the moles of methane present using:
Moles = mass / molecular mass
Moles = 20 / 16
Moles = 1.25

Next, we may observe from the chemical equation that the molar ratio between methane and oxygen is 1 : 2
So the moles of oxygen required are 2 x 1.25
2.5 moles of oxygen required

Mass = moles * molecular mass
Mass = 2.5 * 32
Moles = 80

C. 80 grams O₂