please answer question from 5 chemical literature and 6 ir spectroscopy. Thank y

Question

please answer question from 5 chemical literature and 6 ir spectroscopy. Thank you

which layer is on the top? you tell if the extracted solution is "dry"? g- 5. Chemical Literature aWhat are some common sources of chemical information? Where would you look to find physical properties? Reactions? Journal reference articles? bWhat is a CAS number? c Be familiar with how to use the above sources: on line 6. IR Spectroscopy a What is IR? What does it measure? b. Which bonds are typically IR active? Which are not? Which absorb strongly? Which are weak? c What does it tell you about a compound? Can it be used to conclusively identify a structure? d·What does an IR spectrum!ook like? where is the baseline? What is an absorbance? What are the typical wavelengths? Wavenumbers? Where is the fingerprint region? e.What does "conjugation" mean? How does this affect an IR frequency? Why? . Which molecules form hydrogen bonds? How does hydrogen bonding affect IR frequency?

Explanation / Answer

5. - Some common sources of chemical informations are , CRC handbook, scifinder, wikkipedia, etc. Physical properties can be found in any of these sources. Reactions are mentioned in scifinder. Journal references are also mentioned in scifinder source.

- CAS is chemical abstract service is a specific number assigned to each compound that has been made or has been identified fully.

- the web search would take you to these searc engines and typing the keywords give the information list needed.

6. IR spectroscopy

- IR is infrared spectroscopy is a technique in which specific bonds absorb infrarad radiation specific to that bond and causes vibrational changes. It measures vibrational energy of bonds.

- All bonds are vibrationally active. The bonds with pi-electrons are typically more active in IR and show strong peaks. The single bonds are weak peaks.

- It tells us the type of bonds present in a compound. The technique can be used to identify and confirm the type of functional group in a compound.

- A typical IR sectrum plots absorbance versus wavenumber (v-1). The absorbance is the amount of IR radiation absorbed by the specific bond displayed in frequency. Wavelengths are inverse of wavenumber. So as wavenumber increases, wavelength for the bonds decreases. Fingerprint region is between 500-1500 cm-1 region in the IR spectrum. Like the name suggests every compound has this region typical for that compound and it does not match with any other compound like the fingerprints uniqueness.

- When a series of pi-bonds are connected by alternate single bonds or pi-bonds attached to groups that have lone pair of electrons, they are called in conjugation. Conjugation decreases the double bond character and thus lower frequency of absorption in the IR spectrum.

- Hydrogen bonds are formed by moelcules which have functional groups having an electronegative atom attached to hydrogen like -OH, -NH2, etc. Hydrogen bonding broadens the peak in IR spectrum for groups. For example reduces the frequency of -O-H bond.

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