[tex]2.4 \times 10^{-2} \; \text{mol} \cdot \text{s}^{-1}[/tex]
Explanation
Referring to coefficients of [tex]\text{KClO}_3[/tex] and [tex]\text{KCl}[/tex] the equation, the decomposition of every [tex]2[/tex] moles of potassium chlorate would yield [tex]2[/tex] moles of potassium chloride. At any time in the reaction process the rate of production of [tex]\text{KCl}[/tex] shall equals to the rate at which [tex]\text{KClO}_3[/tex] is being consumed.
The question states that the reaction consumes [tex]2.4 \times 10^{2} \; \text{mol}[/tex] of [tex]\text{KClO}_3[/tex] every single second on average. One would thus expect it to produce the same amount of [tex]\text{KCl}[/tex] in the same period of time. [tex]\text{KCl}[/tex] is thus produced at a rate of [tex]2.4 \times 10^{2} \; \text{mol} \cdot \text{s}^{-1}[/tex]