Question

Which species has the greatest rate of disappearance in the reaction below?

CH₄ + 2 O₂ → 2 CO₂ + H₂O

Answer 1

$CO_{2}$  has the greatest rate of disappearance in the reaction.

Answer 2

Answer:

Thus, the greatest rate of disappearance is shown by O₂.

Explanation:

The rate of a reaction is equal to the change in concentration divided by the time interval in which the change has taken place.

As the concentration of reactants decreases, a negative sign is used to express the rate of reaction in terms of reactants. As the concentration of product increases, a positive sign is used in terms of products.

For a reaction aA + bB → xX + yY

The rate of disappearance of A = $-\frac{1}{a} \frac{d[A]}{dt}$

The rate of disappearance of B = $-\frac{1}{b} \frac{d[B]}{dt}$

In this reaction, the rate of disappearance of CH₄=$-\frac{d[CH4]}{dt}$

The rate of disappearance of O₂=$-\frac{1}{2} \frac{d[O2]}{dt}$

O₂ gas reacts at twice the rate of CH₄.

Thus, the greatest rate of disappearance is shown by O₂.