Zero Order Reactions

To solve this problem, we need to understand the characteristics of a zero-order chemical reaction. In a zero-order reaction, the rate of reaction is constant and independent of the concentration of the reactants.

The rate equation for a zero-order reaction can be expressed as:

where is the rate constant.

The integrated rate law for a zero-order reaction is given by:

where is the concentration of the reactant at time , is the initial concentration, is the rate constant, and is the time elapsed.

This equation resembles the equation of a straight line:

In this context, the concentration acts as , time as , as the slope , and as the intercept .

Therefore, for a zero-order reaction, a plot of vs. will be a straight line with a negative slope. Given the options, the correct graph that represents a zero-order reaction is:

This graph clearly shows a linear decrease in concentration over time, indicating a zero-order reaction.

Let's summarize why other options are incorrect:

• Other graphs would represent different order reactions (like first or second order) typically showing a nonlinear relationship between the concentration and time.

From the graph, we know that is proportional to .
The slope is given as 76.92. Thus, using the equation for zero-order reaction: Thus, Now, applying the formula for zero-order reaction: Thus, the concentration of A at 10 minutes is .

Concept:

• Zero order reaction Thus,
• First order reaction In first order reactions, reactant concentration approaches zero asymptotically, so the reaction never reaches exactly completion. Thus,