Chem 302

Midterm Exam

Part A

April 19, 1994

Name __________

Full credit will be given to correct answers only when ALL the necessary steps are shown. DO NOT GUESS THE ANSWER.

This is a an open book exam, and you are responsible to be sure that your exam has no missing pages(5 pages).

If you consider that there is not enough information to solve a problem, you have to specify the missing information and describe the problem solving procedure.

If therefore angels are not composed of matter and form, as was said above, it follows that it would be impossible to have two angels of the same species

... The motion of an angel can be continuous or discontinuous as it wishes ...

And thus an angel can be at one instant in one place, and at another instant in another place, not existing at any intermediate time.

- Thonas Aquinas (1268)

Honor Statement

I have neither give nor received aid in this examination.

Full signature _______________________________

Problem 1 (20 points)

The infrared spectra of NaCl and KCl consist of intense lines at 378 cmand 278cm. Calculate the force constant.

Problem 2 (30 points)

For the Q.M. H.O., the root-mean-square value of x,

,

is a measure of the oscillation amplitude. Considering the ground state, n=0, for HCl and the experimental value obtained from infrared spectroscopy

,

calculate Aand compare it to the bond length of 107 pm. Remember that is defined by

.

Problem 3 (30 points)

Predict the location of the absorption peak(s) in the microwave rotational spectrum for CO given that the bond length is 0.11286 nm. Give your answer in cm.

Problem 4 (20 points)

For the hydrogen atom calculate the probability of finding an electron between a/2 and 3a/2 for the 1s wave function. Consider a = ain the expresion for y.