Quiz -1 EVS questions

The most abundant Nobel gas in the earth atmosphere?

Argon

Number of layers in the earth atmosphere?

Troposphere

Stratosphere

Mesosphere

Ionosphere

Ozone Layer is present in which layer of the atmosphere?

Stratosphere

What is the full form of ICAR?

Indian Council of agricultural research

What is the full form of CPCB?

Central pollution control board

What is the full form of IUCN?

International Union for conservation of nature

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Hooke’s Law for IR spectrscopy

Hooke's Law is an equation which help s in interpreting the molecular vibrations by assuming bonds as spring having masses (atoms) at two ends. When a molecule is exposed to infrared light, the bonds between atoms can absorb specific frequencies of that light, causing the bonds to stretch , compress or bend , just like a spring. This characteristic absorption of light corresponding to certain specific vibrational frequencies helps in identifying the functional groups in that molecule and thus adding to the characterization of molecular structures. The mathematical expression of Hooke’s law is given as follows: ν = 1/2π√k/µ ῡ = 1/2πc√k/µ where: · ν = the frequency of vibration · ῡ = Wave number (reciprocal of wavelength) · k = the force constant · c = Velocity of light · Π = Constant · μ = reduced mass The reduced mass of the two atoms involved in the bond is calc...

Bathochromic and Hypsochromic Shift

B athochromic shift - It is the shift of the absorption maxima (λ max ) of a substance towards longer wavelengths . It is also known as red shift . Since, Energy (E) is inversely proportional to Wavelength. So, in Bathochromic shift----energy decreases and wavelength increases. In Bathochromic shift, energy decreases and wavelength increases. Factors causing Bathochromic shift: The bathochromic shift is caused by following: A. Extending Conjugation i. either by increasing double bonds ii. or by adding electron donating groups ( like -OH, -NH 2 ) in conjugation to double bonds. B. Solvent Effects i. The less polar (non-polar) solvents cause bathochromic shift for n-π* transitions. ii. The more polar (polar) solvents cause bathochromic shift for π-π* transitions. Example: Benzene shows π-π* electronic transitions at 255 nm. Adding auxochrome NH 2 to the benzene ring makes it aniline an...

Atomic Absorption Spectrometry

Atomic Absorption Spectrometry is an absorption spectroscopic technique in which radiation of a particular frequency from a source is absorbed by non-excited neutral gaseous atoms generated in an atomizer in their ground state. The light is absorbed in the UV-visible region and makes transitions to higher electronic energy levels. The amount of light absorbed is quantified and this amount of absorption helps in determining the analyte concentration. (It follows Beer's Law) The concentration is measured by drawing a calibration curve after calibrating instrument with a standard of known concentration. Factors affecting the amount of light absorbed Length of path transversed Concentration of absorbing atoms in the vapour state. The diagrammatic representation of Atomic Absorption Spectrometer are shown in the below diagram: Components Used in Atomic Absorbance Spectrometer: 1. Hollow Cathode Lamp: Acts as source of radiation It is a sha...

Chemistry Notes for B.Sc. and M.Sc.

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