Chemical Instrumentation Test 1

Chemical Instrumentation Test 1
Uv-Vis

measures electronic transitions in molecule

FTIR

measures vibrational frequencies of bonds in molecule

Mass Spec

# of ions of specific mass to charge ratio--> extends ability to weigh objects

Chromatography

separation of mixture

UV region of light (nm)

195 nm to 400 nm

Visible region of light (nm)

400 nm to 900 nm

Why are UV-Vis peaks broad?

1) multiple vibrational and rotational transformations with each electronic transformation

2) interactions between absorbing species and solvent causes changes in the ground and excited

states for transitions

so... poor choice for qualitative but good for quantitative

Is IR better for qualitative or quantitative studies?

, Qualitative because it has narrow peaks --> good for structural info

Is NMR better for qualitative or quantitative studies?

Qualitative--> get info on structure, connectivity and orientation

Is MS better for qualitative or quantitative studies?

BOTH

What are the basic electrical components?

Resistor, Capacitor, Inductor

Direct Current (DC)

Constant in time and powered by batteries, power supplies, or solar cells

Alternating Current (AC)

Currents change in time and walla socket is example of power source

Current (amperes)

Amount of charge that flows past a point in the circuit in a given amount of time

Voltage (volts)

Potential energy per charge measured in J/C or volts

Ohm's Law

V=IR

Resistance (ohms)