Question
Question: Which of the following graphs are correct for zero – order reaction? A.
Complete Step By Step Solution:
The Haber process produces ammonia from hydrogen and nitrogen gas. The reverse of this process (the decomposition of ammonia to form nitrogen and hydrogen) is a zero-order reaction.
For a zero-order reaction, t21=2k[A]0. Thus, as the initial concentration increases, the half-life increases. Hence, graph A is correct.
Also, [Ao]−[A]=kt.. Hence, with an increase in time, x increases and a−x decreases. So graph B and C are also correct.
For the first-order reaction, the half-life period is independent of the concentration. Hence, graph D is for the first-order reaction.
Hence, graph A,B and C are correct for zero order reaction.
Note: The rate law for a zero-order reaction is rate = k, where k is the rate constant. In the case of a zero-order reaction, the rate constant k will have units of concentration/time, such as M/s. For a zero order reaction, as shown in the following figure, the plot of [A] versus time is a straight line with k = - slope of the line. Other graphs are curved for a zero order reaction.