Infrared Spectrophotometer

Q. 1 what is the application of IR spectrophotometer

Answer:

It is used to

1. Functional group in a compound2. Identify a polymer through databases3. Can determine concentration of constituent in a mixture

Q.2 what is the principle of working of IR spectrophotometer

Answer. IR uses the fact that molecule have specific frequencies at which they rotate or vibrate.

Q.3 Name some type of motion occurs in a molecule by passing IR radiation.

Answer:

Rocking Wagging, Twisting Scissoring

Q.4 what three regions exist in IR spectrum

Answer: Near IR, Medium IR and Far IR(Fingerprint region)

Q.5 which material is used to put liquid or solid sample in IR

Answer: Potassium Bromide tablets

Q. 6.Define path length, why is it calculated

Answer: Path length is the distance between the internal windows of cell. It is determined by the formula b = N/2(Ϭ1-Ϭ2)

Q. 7 what happens when radiation passed through the cell windows.

Answer: When radiation passed through cell windows, interference takes place.

Q. 8 write some important parts of IR spectrophotometer

Answer: IR source, Sample holder, Splitter, detector, Computer, printer

Q. 9. Give some disadvantages of IR spectrophotometer

Answer:

1. If absorption is not in the range 4000cm-1 to 400cm-1 it will not show on spectrum.2. Additional weak bands appear in the graph3. Absorption can be too close to each other