Mass spectrometry (MS)

Highly energetic ions, may break in smaller fragments, some of which may be ions.

Section 28 of data booklet shows fragmentation pattern
Qualitative analysis

Based on chemical or physical properties

reactivity

solubility

melting point

mass spectra

etc.
Quantitative analysis

Amount or concentration expressed as numerical values and appropriate units.
Precision

the closeness of agreement between independent test results

lower random error= higher precision
Accuracy

the closeness of the agreement between results and the true
Significant Figures

Number of figures reflecting the precision of a given measurement
Systematic errors

Flaw in the design of the experiment or misuse of equipment

Instrumental errors

Example: Faulty calibration of equipment


Experimental methodology errors

Example: Calorimeter insulation


Personal errors

Example: Reading of graduated cylinder



Affect accuracy

improve: adopt greater care to experimental design
Random erros

Cannot be eliminated, but reduced> repeated measurement

affect precision

Example: estimating quamtity between graduations
Absolute and relative uncertainty

Absolute: related to measurement

Relative: related to size of measurement (%)
Slope of a line

tangent at a certain point
Intercept

extrapolation

y=ax+b
Best fit line

Trendline

Need R squared
Sketch

Labelled but unscaled axis

show proportiality
Graph

Labelled and scaled axis

quantitative measurement
Index of hydrogen deficiency (IHD)

used to determine number of rings or multiple bonds in a molecule

degree of unsaturation is used to calculate the number of pi bonds and number of rings where:

Double bond: one degree

Triple bond: two degree

Ring:one degree

Aromatic ring: four degree


OR: IHD = 0.5(2c+2hx+n)
Infrared spectroscopy

Identifies various functional groups

based on spring model

symmetric stretch

symmetric bend

asymmetric stretch


Fingerprint region should not be taken into consideration
Proton nuclear magnetic resonance (1HNMR)

Information between different chemical environments of hydrogen atoms

Table 27 of data booklet

shows the relative number of hydrogen atoms present