Singlet

gas Helium Phase at STP gas Melting point 0.95 K ​(−272.20 °C, ​−457.96 °F) (at 2.5 MPa) Boiling point 4.222 K ​(−268.928 °C, ​−452.070 °F) Density (at STP) 0.1786 g/L Is helium a gas or liquid? gaseousHELIUM (Greek helios, “sun”), symbol He, inert, colorless, odorless gaseous element. In group 18 (or VIIIa) of the periodic […]

Hence, we conclude that, in excited states of helium, the spin-singlet state has a higher energy than the corresponding spin-triplet state. Incidentally, helium in the spin-singlet state is known as parahelium, whereas helium in the triplet state is called orthohelium. What is para helium? parahelium (uncountable) (physics) The form of the helium atom in which […]

Benzyl. Explanation: The correct stability order of carbocation is- Benzyl > 30 > 20 > 10. Benzyl carbocation is the most stable and 10 carbocation is least stable. Which carbocation is most stable? A tertiary carbocation is the most stable carbocation due to the electron releasing effect of three methyl groups. Which of the following […]

Molecular oxygen. Molecular oxygen (O2) is a diatomic molecule that is composed of two oxygen atoms held together by a covalent bond. Molecular oxygen is essential for life, as it is used for respiration by many organisms. Is O2 an element or a molecule? Solution : `O_2` is a compound , because `O_2` is formed […]

This state is referred to by the title term, singlet oxygen, commonly abbreviated 1O2, to distinguish it from the triplet ground state molecule, 3O2. How do you represent a singlet oxygen? Singlet oxygen (represented as 1ΔgO2, abbreviated as 1O2) is not a radical and represents an excited state of O2 in which the spin of […]

A proton at higher chemical shift values is deshielded, so the aromatic protons are obviously less shielded than aliphatic protons. One effect that causes deshielding is the presense of electronegative atoms that draw electrons away from other atoms and thereby deshield them. Why is aromatic Deshielded? In benzene, the ring protons experience deshielding because the […]

As you read the spectrum of benzene from left to right, note there are three peaks between 3200 and 2800 cm–1, making these C-H stretches. How many peaks are in benzene carbon NMR? Acetone shows two peaks, one for the methyls and one for the carbonyl carbon. Ethyl benzoate shows 7 peaks; the benzene ring […]

sp2 hybridization is also called trigonal hybridization. It involves mixing of one ‘s’ orbital and two ‘p’ orbital’s of equal energy to give a new hybrid orbital known as sp2. A mixture of s and p orbital formed in trigonal symmetry and is maintained at 1200. What are sp2 orbitals? sp2 orbital: One of a […]

Singlet, doublet and triplet is derived using the equation for multiplicity, 2S+1, where S is the total spin angular momentum (sum of all the electron spins). Individual spins are denoted as spin up (s = +1/2) or spin down (s = -1/2). How do you calculate spin multiplicity? Spin multiplicity is based on the number […]

The rule states that for a given electron configuration, the lowest energy term is the one with the greatest value of spin multiplicity. This implies that if two or more orbitals of equal energy are available, electrons will occupy them singly before filling them in pairs. What is the maximum and minimum spin multiplicity? When […]

The superscript three (read as triplet) indicates that the multiplicity 2S+1 = 3, so that the total spin S = 1. This spin is due to two unpaired electrons, as a result of Hund’s rule which favors the single filling of degenerate orbitals. What is the multiplicity of triplet excited state? If the spin multiplicity […]

Explanation: In 1H NMR, there are 4 different set of protons present. Therefore, 4 signals are observed. How do you find the number of 1H NMR signals? The number of signals these molecule’s produce in a 1H NMR spectrum can be determined just by counting the number of distinct hydrogens on one side of the […]

Spin multiplicity is based on the number of unpaired electron, =2S+1. Where S=n(1/2). What is the formula of multiplicity? In spectroscopy and quantum chemistry, the multiplicity of an energy level is defined as 2S+1, where S is the total spin angular momentum. What is spin multiplicity? Hint:Spin multiplicity is the number of probable orientations of […]

Reference Compounds Tetramethylsilane became the established internal reference compound for 1H NMR because it has a strong, sharp resonance line from its 12 protons, with a chemical shift at low resonance frequency relative to almost all other 1H resonances. Which of the following is used as reference standard in NMR spectroscopy? The 1H sensitivity standard […]

No. Hydrogen Cyanide,hydrogen sulfide, Sarin nerve gas,Tabun nerve gas, carbon monoxide; F2,Cl2; these are all more toxic than oxygen. In addition. gases may not be toxic in and of themselves. What is the deadliest gas? What is the most dangerous gas in the world? Hydrogen sulfide – In high enough concentrations, inhaling this gas results […]

Well, not as much as you might think. The breathing fluid depicted in the film, oxygenated perfluorocarbon, actually exists, and while scenes with the diving suit were filmed with Ed Harris holding his breath, an earlier scene in which a rat is immersed in breathing fluid was filmed for real. Is there a liquid that […]

Like vitamin C tablets, once the body has absorbed its daily needs, there’s no point in pumping more in. Decades of research have come up with no evidence that breathing pure oxygen makes healthy subjects intoxicated, euphoric or energetic. What does pure oxygen do to you? To breathe pure oxygen at that level for any […]

Once in their suits, astronauts breathe pure oxygen for a few hours. Breathing only oxygen gets rid of all the nitrogen in an astronaut’s body. If they didn’t get rid of the nitrogen, the astronauts might get gas bubbles in their body when they walked in space. Do they use pure oxygen in space? Re: […]

The concentration of oxygen in normal air is only 21%. The high concentration of oxygen can help to provide enough oxygen for all of the organs in the body. Unfortunately, breathing 100% oxygen for long periods of time can cause changes in the lungs, which are potentially harmful. How long can you breathe 100% oxygen? […]

All of these individual molecules are constantly rearranged and recycled through biochemical and geochemical processes, so you aren’t breathing in the exact same gas molecules that dinosaurs and Julius Caesar once breathed. Can humans breathe in prehistoric times? Between 850 and 600 million years ago, oxygen concentrations increased steadily from 2 to about 10 per […]