Question

Consider the reaction A $\to$ B. Which of the following defines the rate of this reaction?

• A. -d[A]/dt
• B. +d[A]/dt
• C. -d[B]/dt
• D. d[A+B]/dt

Answer 1

The correct option is A

-d[A]/dt

The rate of a chemical reaction is defined as the change in concentration of any one of the reactants or products per unit time.

Consider the reaction A $\to$ B,

Rate of the reaction is given by,

Rate =$-\frac{d\left[A\right]}{dt}=+\frac{d\left[B\right]}{dt}.$

Where, [A] $\to$ concentration of reactant A

[B] $\to$ concentration of product B

(-) Negative sign indicates a decrease in concentration of A with time.

(+) Positive sign indicates an increase in concentration of B with time.

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