Spectroscopy 1

<p>They are inversely proportional</p> Signup and view all the answers

<p>The interaction between light and molecules</p> Signup and view all the answers

<p>Double bonds and conjugated systems</p> Signup and view all the answers

<p>E = hn</p> Signup and view all the answers

<p>Absorbance peaks</p> Signup and view all the answers

<p>λn = c</p> Signup and view all the answers

<p>They absorb specific wavelengths of light</p> Signup and view all the answers

<p>Drug degradation kinetics</p> Signup and view all the answers

<p>Energy decreases as wavelength increases</p> Signup and view all the answers

<p>Partition coefficients</p> Signup and view all the answers

<p>Directly proportional</p> Signup and view all the answers

<p>c = λn</p> Signup and view all the answers

<p>It has only one wavelength.</p> Signup and view all the answers

<p>They carry more energy than IR photons.</p> Signup and view all the answers

<p>It simplifies calculations involving energy.</p> Signup and view all the answers

<p>800 to 400 nm</p> Signup and view all the answers

<p>E = hn</p> Signup and view all the answers

<p>It is equal to the product of wavelength and frequency.</p> Signup and view all the answers

<p>A chromophore is the part of a molecule responsible for UV or visible light absorption, allowing molecules with conjugated π bonds to absorb light.</p> Signup and view all the answers

<p>Extended conjugation in chromophores leads to absorption at longer wavelengths due to decreased energy gap between the HOMO and LUMO.</p> Signup and view all the answers

<p>Compounds with long chromophores typically absorb in the visible region, which signifies that they may appear colored.</p> Signup and view all the answers

<p>Only molecules with conjugated π bonds can absorb in the UV spectrum because they possess the necessary energy levels for electronic transitions.</p> Signup and view all the answers

<p>The structure of a chromophore, particularly the degree of conjugation and types of functional groups, directly influences its absorption wavelength and intensity.</p> Signup and view all the answers

<p>The dual nature allows researchers to understand and analyze molecular interactions at both the particulate and wave level, essential for determining structural characteristics.</p> Signup and view all the answers

<p>Conjugation increases the delocalization of electrons within a molecule, leading to lower energy gaps between molecular orbitals, thus allowing the absorption of longer wavelengths in the UV-Vis spectrum.</p> Signup and view all the answers

<p>Planck's constant is a fundamental constant that links the energy of a photon to its frequency, allowing calculations of photon energy by the equation E = hn.</p> Signup and view all the answers

<p>Understanding the electromagnetic spectrum helps identify how different frequencies and wavelengths interact with various functional groups in organic compounds, providing critical insights into their structural features.</p> Signup and view all the answers

<p>The electric and magnetic vectors being perpendicular to each other define the propagation of electromagnetic waves, which is fundamental for the interaction of these waves with matter in spectroscopic techniques.</p> Signup and view all the answers

<p>Frequency is calculated using the formula $n = \frac{c}{\lambda}$, where $c$ is the speed of light and $\lambda$ is the wavelength.</p> Signup and view all the answers

<p>The energy is calculated as $E = h n = 3.78 x 10^{-19}$ J, using Planck's constant.</p> Signup and view all the answers

<p>Wavenumber is significant because it is directly proportional to energy, making it a useful measurement in infrared spectroscopy.</p> Signup and view all the answers

<p>Monochromatic radiation consists of a single wavelength, while polychromatic radiation contains multiple wavelengths.</p> Signup and view all the answers

<p>Ultraviolet photons carry more energy than infrared photons due to their higher frequency.</p> Signup and view all the answers

<p>The speed of light in a vacuum is approximately $2.998 x 10^8$ m/s and is essential for calculating frequency and energy of electromagnetic radiation.</p> Signup and view all the answers

<p>Sunlight is considered a continuum source because it emits a wide range of wavelengths, peaking in the visible region from 400 to 800 nm.</p> Signup and view all the answers

<p>The energy of monochromatic radiation depends only on its frequency or wavelength, not on the intensity of the beam.</p> Signup and view all the answers

<p>The presence of a chromophore in the molecule.</p> Signup and view all the answers

<p>Double bonds, lone pairs of electrons, and conjugated systems.</p> Signup and view all the answers

<p>It allows for the quantification of drugs in formulations and monitors their degradation over time.</p> Signup and view all the answers

<p>It relates the energy of photons to their wavelength.</p> Signup and view all the answers

<p>It helps determine the solubility and partition coefficients through absorbance measurements.</p> Signup and view all the answers

<p>It allows for the observation of drug concentrations over time during dissolution testing.</p> Signup and view all the answers

<p>It includes radiation of different wavelengths, which relates to energy and frequency.</p> Signup and view all the answers

<p>It can be used for pharmacopoeial identity checks to ensure drug quality.</p> Signup and view all the answers

<p>The ground state of a molecule is its normal electronic configuration where electrons occupy the lowest energy orbitals.</p> Signup and view all the answers

<p>The λmax indicates the wavelength at which a molecule absorbs the maximum amount of UV-Vis light, reflecting its electronic transitions.</p> Signup and view all the answers

<p>n → π* represents the promotion of a nonbonding electron to a π antibonding molecular orbital, while π → π* indicates the promotion of an electron from a π bonding to a π antibonding orbital.</p> Signup and view all the answers

<p>Conjugation raises the energy of the HOMO and lowers the energy of the LUMO, resulting in less energy required for electronic transitions.</p> Signup and view all the answers

<p>Absorption bands below 210 nm are usually obscured by O2 in the atmosphere, which absorbs in that region.</p> Signup and view all the answers

<p>Excitation occurs when a photon with sufficient energy causes an electron to transition from the ground state to an excited state.</p> Signup and view all the answers

<p>n → π* transitions require less energy and involve longer wavelengths, while π → π* transitions require more energy and shorter wavelengths.</p> Signup and view all the answers

<p>Acetone has λmax values of 274 nm for n → π* and 195 nm for π → π*, while methyl vinyl ketone has higher λmax values of 324 nm and 219 nm due to its conjugated system.</p> Signup and view all the answers