For the zero-order reaction a → products, what is the rate when [a] = 0.200 M and k = 3.57 M/min?

• A. 0.714 M/min
• B. 17.85 M/min
• C. 0.200 M/min
• D. 3.57 M/min

Answer: (D)

Verified step by step guidance

1. Identify the order of the reaction. Since it is a zero-order reaction, the rate does not depend on the concentration of reactant [a].
2. Recall the rate law for a zero-order reaction: \(\text{rate} = k\), where \(k\) is the rate constant with units of concentration/time (e.g., M/min).
3. Note the given values: \([a] = 0.200\ \text{M}\) and \(k = 3.57\ \text{M/min}\). For zero-order, the concentration does not affect the rate.
4. Apply the zero-order rate law by substituting the given rate constant: \(\text{rate} = 3.57\ \text{M/min}\).
5. Conclude that the rate of the reaction is equal to the rate constant \(k\), regardless of the concentration of \(a\).