ANALYTICAL CHEMISTRY FINAL- ACS EXAM QUESTIONS AND ANSWERS

ANALYTICAL CHEMISTRY FINAL- ACS
EXAM QUESTIONS AND ANSWERS



ppm - Correct Answers -(grams analyte/grams sample)x10^6

Molarity - Correct Answers -moles analyte/liter of solution

Volume Percent - Correct Answers -(volume solute/volume soution)x100

Volume ppm - Correct Answers -(volume solute/volume solution)x10^6

kilo- - Correct Answers -10^3

deci- - Correct Answers -10^-1

centi- - Correct Answers -10^-2

milli- - Correct Answers -10^-3

micro- - Correct Answers -10^-6

nano- - Correct Answers -10^-9

pico- - Correct Answers -10^-12

femto- - Correct Answers -10^-15

weight percent - Correct Answers -(grams analyte/grams sample)x100

ppt - Correct Answers -(grams analyte/grams sample)x10^3

ppt simplified - Correct Answers -gram analyte/liter solution

ppm simplified - Correct Answers -mg analyte/liter solution

ppb simplified - Correct Answers -micrograms analyte/liter solution

pptr simplified - Correct Answers -nanograms analyte/liter solution

, buoyancy correction - Correct Answers -m=(m'(1-(air density/weight density)))/(1-(air
density/object density))

accuracy - Correct Answers -closeness of the mean to the "true value"

precision - Correct Answers -reproducibility of individual measurements

Uncertainty in Addition/Subraction - Correct Answers -e=sqrt(ex1^2+ex2^2+ex3^2+...)

Uncertainty in Multiplication/Division - Correct Answers
-e=y*sqrt((ex1/x1)^2+(ex2/x2)^2+(ex3/x3)^2+...)

Significant Figures in Logarithms and antilogarithms - Correct Answers -the number of
significant figures in the log should equal the number of digits in the mantissa

How many significant figures in log(205.5) - Correct Answers -four significant figures, so
you will need four decimal places in your answer

pH - Correct Answers --log[H3O+]

[H3O+] - Correct Answers -10^-pH

Absorbance - Correct Answers --log(transmittance)

Random Error - Correct Answers --repeated measurements are sometimes high and
sometimes low
-cannot be corrected for

Systematic Error - Correct Answers --repeated measurements are usually always high
or always low
-can and should be corrected for

Relative uncertainty= - Correct Answers -absolute uncertainty/magnitude of
measurement

68% of measurements in a Gaussian Curve will lie - Correct Answers -between the
mean-1 and the mean+1

Variance in standard deviation - Correct Answers -standard deviation squared

mean= - Correct Answers -true value +-time*standard deviation

T-test Case 1 - Correct Answers -measure sample of known composition

T-test case 2 - Correct Answers -compare replicate measurement of an unknown
sample