From graph, predict the order of the reaction:

Zero order reaction

The correct answer is option 3. Zero order reaction.

A zero-order reaction is a type of chemical reaction in which the rate of the reaction is independent of the concentration of the reactant(s).

Integrated Rate Equation for Zero Order Reaction:

Let us consider the general reaction:

\(A \longrightarrow \, \ Products\)

If it is a reaction of zero order, then rate of reaction will be

\(- \frac{d[A]}{dt} = k[A]^0\)

or, \(- \frac{d[A]}{dt} = k\)     [Since, \([A]^0 = 1\)]

or, \(d[A] = -kdt\) --------(i)

Integrating both sides, we get

\(\int{d[A]} = -k\int{dt}\)

or, \([A] = -kt + c\) ----------(ii)

where, \(c\) is the constant of integration

At, \(t = 0\), \([A] = [A]_0\)

\(∴ [A]_0 = c\)

Substituting this value in equation (ii), we get

\([A] = -kt + [A]_0\)

or, \(kt = [A]_0 - [A]\)

or, \(k = \frac{1}{t}\left([A]_0 - [A]\right)\) -------(iii)

This is the expression for rate constant for reactions of zero order.

From zero order reaction, we have

\([A] = -kt + [A]_0\)

As it is in the form of a straight line, \(y = mx  + c\), where, slope, \(m = -k\) and the intercept, \(c = [A]_0\) versus time, \(t\) will be