Question

why does the concentration of CV + never enter specifically into the calculations for the alkanline hydrolysis crystal violet lab

Answer 1

The concentration of - OH will be approximately many times higher In all the trials, the hydroxide ion is in huge excess and can be assumed constant - neither will change appreciably during the reaction. Therefore, the hydroxide's concentration term and reaction order is grouped with the rate constant, k, to create the pseudo rate constants, k1 and k2. This allows for the simplification of the rate law

: rate1 = -Δ[CV+ ]/Δt = k1 [CV+ ]^m where k1 = k[OH– ]1^n

rate2 = -Δ[CV+ ] /Δt= k2 [CV+ ]^m where k2 = k[OH– ]2^n

To find the reaction order of CV+ , m, and the pseudo rate constants, k1 and k2, differential rate laws expressed in equations 3 & 4 must be integrated.

Because, k, the actual rate constant, does not change (and is the same in both trials), the order of reaction with respect to OH– (n) is found from the ratio of the pseudo rate constants and the ratio of the concentrations of hydroxide ion used in trials shown above and the CV+ does not come to the calculations.