Class Notes (1,100,000)

CA (650,000)

UVic (3,000)

CHEM (200)

CHEM 212 (10)

Hamilton M.Coreen (10)

Lecture 6

# CHEM 212 Lecture Notes - Lecture 6: Potassium Hydrogen Phthalate, Desiccator, Sodium Carbonate

by OC816556

School

University of VictoriaDepartment

ChemistryCourse Code

CHEM 212Professor

Hamilton M.CoreenLecture

6This

**preview**shows half of the first page. to view the full**3 pages of the document.**Chem 212!

Lecture 6!

Sept. 20/2016!

!

Stats overview:!

Conﬁdence Intervals --> mu= xbar+/- (ts/n^1/2)!1.

Comparing 2 sets of data --> two choices!2.

Grubbs Test --> Reject bad data!3.

!

Comparing 2 sets of Data:!

"-Should you average each set of data?!

""-If its repeat measurements of the same thing, then you should average!

""-Don't average if you expect the data to be diﬀerent!

!

!

!

""""YES""""""""NO""""""""""""""""""""""""""""""""dbar= diﬀerence average!

!

!

!

!

"""F-Test on Sa/Sb"""""Calculate diﬀerence for each pair of data!

!

!

Passes (no sig. diﬀ)" " Fails (Sig diﬀ)!

""""""""""""Calculate dbar, Sd, use EQN with dbar and Sd!

""""""""""""!

!

" " " " " " " " " " " " """""""""""""𝝂=no. of pairs -1!

t-test via EQN 1"""t-test EQN 2!

!

!

!

!

uses S-pooled""""Requires calc for!

"𝝂=n1+n2-2" " " " 𝝂=("𝝂/N)-2 ******?!

!

!

!

!

NEVER STOP AT AN F_TEST --> continue to T TEST!

Number of data sets in paired must be equal!

Number of data sets in unpaired do not have to be equal!

THEREFORE a hint for which pathway to choose !

!

!

Quantiﬁcation:

Turn raw data into results!

!

Sample: analyte in a matrix!

Matrix: Rest of the sample!

"Example. Measuring Fe in water versus in blood. !

Standard: pure chemical or solution of known chemical concentration!

Blank: reagent blank, method blank, instrument blank, ﬁeld blank, etc. Used to check for contamination. Analyzed

like an unknown sample. Everything but the sample.!

Blank really important when target concentration of what you are trying to me sure in your sample is very low. ppb!

QC or know sample: Has a known concentration of analyte. May may not have matrix!

Reference material: sample (has matrix) of known concentration of analyte. Buy from certiﬁed company $$$$!

!

###### You're Reading a Preview

Unlock to view full version