Chemical Kinetics 1

Question 1

The rate of the chemical reaction can be monitored via Beer’s law and spectrophotometer absorbance reading; as the reaction moves in a forward direction, the concentration of crystal violet analyte in solution will __________ and the absorbance reading will ________.

Answer 1

decrease; decrease

Question 2

Using the method of integrated rate laws, I am trying to determine the reaction order with respect to A
in the following reaction:

2A + B –> A2B

I made three plots: concentration of A
(units of molarity, M) vs time (s); the natural logarithm of the concentration of A
vs time (s); and the inverse concentration of A
(M-1) vs time (s).

The following graph yielded a straight line:
Based on your pre-lab reading, what is the order of the reaction with respect to A
and what are the units of the slope m
?

Answer 2

This is a second order reaction with respect to A. The units on the slope are M-1s-1.

Question 3

When using a micropipette, it is important to maintain a vertical orientation of the device with the tip pointing towards the floor. This will prevent any corrosive liquids from entering the pipette.

Answer 3

True

Question 4

The Beer’s Law relationship is how we will solve for the molar absorptivity coefficient. What is the equation that translates to the linear regression format?

Answer 4

A = m[analyte] + b

Question 5

Molar absorptivity coefficients are dependent upon both the specific analyte and the wavelength of light.

Answer 5

True

Question 6

The spectrophotometer requires what apparatus to collect data?

Answer 6

Cuvettes
Vernier Spectral Analysis Software