Chemistry 155 Introduction to Instrumental Analytical Chemistry

More documents

Recommendations

Info

Chem 155 Unit 2 Page 62 of 313Obviously, the answer has to do with the way that the dependentvariable (A) in this case changes as a function of the independentvariable (P).Consider a calculated value ‘S’ that depends on the measuredquantites, e.g. instrument signals, a,b,c…S = f(a,b,c…)In fact – the variance in S is proportional to the variance in a,b,c –and the proportionality is the partial derivative squared:(Skoog appendix a1B-4 has a derivation if you are curious)for: S f( a±σ a , b±σ b , c±σ c )σ S2⎛⎜⎝δSδa⎞ ⎟⎠2⋅σ a2+⎛⎜⎝δSδb⎞ ⎟⎠2⋅σ b2+⎛⎜⎝δSδc⎞ ⎟⎠2⋅σ c2So – let’s take an example:S = a+b-cfind σ S = f(S,a,σ a , b,σ b ,c,σ c )Note that the larger terms dominate!Page 62 of 313
Chem 155 Unit 2 Page 63 of 313Exercise: Prove the “multiplication / division rule”Show that for S = a*b/cσ S2S 2 σ a2a 2 σ b22σ cb 2 c 2Page 63 of 313
Page 1 and 2:
Chem 155 Unit 1 Page 1 of 313Chemis
Page 3 and 4:
Chem 155 Unit 1 Page 3 of 3131 Over
Page 5 and 6:
Chem 155 Unit 1 Page 5 of 31312 Int
Page 7 and 8:
Chem 155 Unit 1 Page 7 of 3131 Over
Page 9 and 10:
Chem 155 Unit 1 Page 9 of 3131.1.2
Page 11 and 12: Chem 155 Unit 1 Page 11 of 3131.1.4
Page 13 and 14: Chem 155 Unit 1 Page 13 of 3131.3 V
Page 15 and 16: Chem 155 Unit 1 Page 15 of 3131.5 S
Page 17 and 18: Chem 155 Unit 1 Page 17 of 313Confi
Page 19: Chem 155 Unit 1 Page 19 of 3131.5.4
Page 24 and 25: Chem 155 Unit 1 Page 24 of 3131.7 V
Page 34 and 35: Chem 155 Unit 1 Page 34 of 313See a
Page 36 and 37: Chem 155 Unit 1 Page 36 of 3136. Yo
Page 38 and 39: Chem 155 Unit 1 Page 38 of 3131.10.
Page 40 and 41: Chem 155 Unit 1 Page 40 of 3134. Wh
Page 42 and 43: Chem 155 Unit 1 Page 42 of 3137. Ho
Page 44 and 45: Chem 155 Unit 1 Page 44 of 313In ge
Page 46 and 47: Chem 155 Unit 1 Page 46 of 3131.13
Page 52 and 53: Chem 155 Unit 1 Page 52 of 3131.15
Page 56 and 57: Chem 155 Unit 2 Page 56 of 3132 Pro
Page 58 and 59: Chem 155 Unit 2 Page 58 of 313error
Page 60 and 61: Chem 155 Unit 2 Page 60 of 313For a
Page 64: Chem 155 Unit 2 Page 64 of 313The p
show all

Chemistry 155 Introduction to Instrumental Analytical Chemistry

Create successful ePaper yourself

Delete template?

Save as template?