Question

Here is another look at the reaction of crystal violet with sodium hydroxide, a first-order reaction (In $A$ v time):
What is the significance of the slope?

• A. The slope represents the change in concentration over time.
• B. The slope represents the inverse of change in concentration over time.
• C. The slope represents the negative value of the rate constant.
• D. The slope represents the negative rate of product concentration over time.

Answer 1

The correct option is A The slope represents the change in concentration over time.

By graph,$\ln \left[A_t\right]=-Kt+\ln \left[A_o\right]$

$\therefore \ln \left[\frac{A_t}{A_o}\right]=-Kt⟶\left(1\right)$

$K⟶$ Rate constant=slop of graph

$\left[A_t\right],\left[A_o\right]\to$ concentrations of reactant at $t=0,t=5$ respectively.

It is a first order reaction.

$\therefore$ The slop represents change in concentration over time. (from (1))