**CHEMISTRY 133**

**Spring, 2016 Homework Set 1**

**Only Problems in Bold are Submitted for Grading**

**Set 1.1 - Complete
for quiz on Feb. 4**

From Rubinson and Rubinson: 6.1, 6.2, 6.3, 6.5, 6.6, 6.7 [not collected] Solutions to R&R problems

Additional Problems (goes to pdf document) **To be turned in (those in bold)**

Additional Problems - Solutions

** **

**Homework Set 1.2**

**Complete for quiz
on Feb. 18**

R&R Problems: 17.2, 17.3, 17.4

Additional Problems (goes to pdf document)

Solutions to Non-collected problems (R&R problems and Additional problems 1.2.3 and 1.2.7)

Data Set for HW1.2.1 problem

Solutions to Collected Problems (all additional except 1.2.3 and 1.2.7) [updated 2/22/16 because answers to 1.2.2 and 1.2.5 had errors]

**Homework Set 1.3**

Complete by ~~Mar. 3~~ Mar. 1 (but
no quiz planned - Mar. 1 = Exam 1 date)

** **

1.3.1. Which type of noise is best reduced by shielding the critical electronics?

1.3.2. An instrument measures the concentration of a compound in a river that varies on the order of minutes. Most of the noise associated with the measurement occurs at frequencies greater than 1 Hz. Suggest a method (analog or digital) to increase the signal to noise ratio.

1.3.3. What type of noise can be reduced by using internal amplification in a transducer?

1.3.4. What type of noise can be reduced by cooling electrical components?

R&R 6.13

5. A sample is measured 12 times
by a spectroscopic method. The average concentration and standard deviation in
the average are found to be 5.2__+__0.7 μM. With the assumptions made
below answer the following questions:

Assume: 1) noise is purely random, 2) the noise is defined as the standard deviation, and 3) that the standard deviation is well-represented. (The third assumption allows you to avoid using t-factors in signal averaging)

a) What signal to noise ratio would be expected in a single measurement?

b) What is the signal to noise in the average value for the twelve measurements?

c) A researcher needs to have the noise be less than 2% of the value in a particular experiment. How many measurements should she make?

Harris Text: Ch. 13: 1, 5,
10, ~~16, 19, 28, 36~~ [16-36 postponed to HW Set 2.1]