Question

8. A log is burning in a fireplace. If the amount of oxygen reaching the log is decreased, which of the

following statements is true?
The reaction rate increases.
The reaction rate decreases.
The reaction rate remains the same.
The reaction rate only depends on the temperature.

Answer 1

Answer: the reaction rate decreases.

Fire is the result of a combustion reaction, which is the reactionof the organic matter with oxygen. The rate is proportional to amountof oxygen. The, when the amount of oxygen that reaches the organic matter decreases, the rate of combustion decreases too.

Answer 2

Answer is: The reaction rate decreases.

Balanced chemical reaction of burning log:

C(s) + O₂(g) → CO₂(g).

The reaction rate is the speed at which reactants are converted into products.

Reaction rate depends on concentration (amount) of oxygen.

If amount of oxygen decreases, reaction rate also decreases and vice versa.