Meaning Of Dmg In Chemistry
In chemistry, a protic solvent is a solvent that has a hydrogen atom bound to an oxygen (as in a hydroxyl group), a nitrogen (as in an amine group) or a fluorine (as in hydrogen fluoride). In general terms, any solvent that contains a labileH+ is called a protic solvent. The molecules of such solvents readily donate protons (H+) to reagents. Conversely, aprotic solvents cannot donate hydrogen.
Polar protic solvents[edit]
Polar protic solvents are often used to dissolve salts. In general, these solvents have high dielectric constants and high polarity.
Mac OSX DMG file won't open. Problem: After downloading the Mac OSX SimUText installer file, the DMG fails to mount, or you see a second DMG file including the word, 'Part' Action: The installer DMG file did not fully download, the download was interrupted, or otherwise damaged. Dmg won't open on mac sierra. Oct 24, 2019 If you have hardware or software that isn't compatible with macOS Sierra, you might be able to install the previous version, OS X El Capitan. MacOS Sierra won't install on top of a later version of macOS, but you can erase your disk first or install on another disk. Question: Q.dmg won't open in macOS sierra. I downloaded a scanner manager program from Fujitsu that is supposed to be compatible with macOS Sierra, and when i double-click on the installer (.dmg file), it will not open. I have right-clicked on the file and selected 'open,' and I have also clicked on the file, and selected 'open' in the 'File. 1) Try restarting your mac, and trying to open the.DMG again. 2) Hold down the Control key when you click on the.dmg then select Open from the context menu. Theis should give you a. Dec 13, 2017 After it's finish, go to Disk Utility. Open the.dmg file with the Disk Utility still open. You will see the.dmg file on the left of the Disk Utility screen. Click the.dmg.
Common characteristics of protic solvents :
What is Complexometric Titration? Complexometric Titration or chelatometry is a type of volumetric analysis wherein the coloured complex is used to determine the endpoint of the titration.Titration is one of the common method used in laboratories which determines the unknown concentration of an analyte that has been identified. Dag is a measure of weight. Get more information and details on the 'dag' measurement unit, including its symbol, category, and common conversions from dag to other weight units.
- solvents display hydrogen bonding
- solvents have an acidic hydrogen (although they may be very weak acids such as ethanol)
- solvents dissolve salts
- cations by unshared free electron pairs
- anions by hydrogen bonding
Examples include water, most alcohols, formic acid, hydrogen fluoride, and ammonia. Polar protic solvents are favorable for SN1 reactions, while polar aprotic solvents are favorable for SN2 reactions.
Polar aprotic solvents[edit]
Polar aprotic solvents are solvents that lack an acidic hydrogen. Consequently, they are not hydrogen bond donors. These solvents generally have intermediate dielectric constants and polarity. Although discouraging use of the term 'polar aprotic', IUPAC describes such solvents as having both high dielectric constants and high dipole moments, an example being acetonitrile. Other solvents meeting IUPAC's criteria include pyridine, ethyl acetate, DMF, HMPA, and DMSO.[1]
Common characteristics of aprotic solvents:
- solvents that can accept hydrogen bonds
- solvents that do not have acidic hydrogen
- solvents that can dissolve salts
The criteria are relative and very qualitative. A range of acidities are recognized for aprotic solvents. Their ability to dissolve salts depends strongly on the nature of the salt.
Polar aprotic solvents are generally incompatible with strong bases, such as Grignard reagents or t-butyllithium. These reagents require ethers, not nitriles, amides, sulfoxides, etc. The strong base may even deprotonate them ( such as methyl anion as a base having a pKaH of 50, and sulfoxides have pKa of approximately 35.
Properties of common solvents[edit]
The solvents are qualitatively grouped into non-polar, polar aprotic, and polar protic solvents, often ranked by dielectric constant.
| Solvent | Chemical formula | Boiling point | Dielectric constant | Density | Dipole moment (D) |
|---|---|---|---|---|---|
| Non-polar solvents | |||||
| Hexane | CH3-CH2-CH2-CH2-CH2-CH3 | 69 °C | 2.0 | 0.655 g/mL | 0.00 D |
| benzene | C6H6 | 80 °C | 2.3 | 0.879 g/ml | 0.00 D |
| toluene | C6H5CH3 | 111 °C | 2.4 | 0.867 g/mL | 0.36 D |
| 1,4-dioxane | (CH2CH2O)2 | 101 °C | 2.3 | 1.033 g/mL | 0.45 D |
| chloroform | CHCl3 | 61 °C | 4.8 | 1.498 g/mL | 1.04 D |
| diethyl ether | (CH3CH2)2O | 35 °C | 4.3 | 0.713 g/mL | 1.15 D |
| Polar aprotic solvents | |||||
| dichloromethane (DCM) | CH2Cl2 | 40 °C | 9.1 | 1.3266 g/mL | 1.60 D |
| N-methylpyrrolidone | CH3NC(O)C3H6 | 202 °C | 32.2 | 1.028 g/mL | 4.1 D |
| tetrahydrofuran (THF) | C4H8O | 66 °C | 7.5 | 0.886 g/mL | 1.75 D |
| ethyl acetate (EtOAc) | CH3CO2CH2CH3 | 77 °C | 6.0 | 0.894 g/mL | 1.78 D |
| acetone[note 1] | CH3C(O)CH3 | 56 °C | 21 | 0.786 g/mL | 2.88 D |
| dimethylformamide (DMF) | HC(O)N(CH3)2 | 153 °C | 38 | 0.944 g/mL | 3.82 D |
| acetonitrile (MeCN) | CH3CN | 82 °C | 37 | 0.786 g/mL | 3.92 D |
| dimethyl sulfoxide (DMSO) | CH3S(O)CH3 | 189 °C | 47 | 1.092 g/mL | 3.96 D |
| propylene carbonate (PC) | C4H6O3 | 242 °C | 64 | 1.205 g/mL | 4.90 D |
| Polar protic solvents | |||||
| formic acid | HCO2H | 101 °C | 58 | 1.21 g/mL | 1.41 D |
| n-butanol | CH3CH2CH2CH2OH | 118 °C | 18 | 0.810 g/mL | 1.63 D |
| isopropanol (IPA) | (CH3)2CH(OH) | 82 °C | 18 | 0.785 g/mL | 1.66 D |
| nitromethane[note 2] | CH3NO2 | 101°C | 35.87 | 1.1371 g/mL | 3.56 D |
| ethanol (EtOH) | CH3CH2OH | 79 °C | 24.55 | 0.789 g/mL | 1.69 D |
| methanol (MeOH) | CH3OH | 65 °C | 33 | 0.791 g/mL | 1.70 D |
| Acetic acid (AcOH) | CH3CO2H | 118 °C | 6.2 | 1.049 g/mL | 1.74 D |
| Water | H2O | 100 °C | 80 | 1.000 g/mL | 1.85 D |
| note 1 Acetone is subject to keto-enol tautomerism to the enol form (propen-2-ol) and can therefore exhibit a protic behavior. |
| note 2 Although the hydrogen is bonded to the carbon, the carbon is next to a positively charged nitrogen and it is double bonded to an oxygen. |
See also[edit]
References[edit]
- ^IUPAC, Compendium of Chemical Terminology, 2nd ed. (the 'Gold Book') (1997). Online corrected version: (2006–) 'dipolar aprotic solvent'. doi:10.1351/goldbook.D01751
- Loudon, G. Mark. Organic Chemistry 4th ed. New York: Oxford University Press. 2002. pg 317.
- https://pubchem.ncbi.nlm.nih.gov/compound/dimethyl_sulfoxide#section=Top
- Dr.Paul.o.victory
- Africaan's chemical press.2010.pg405
Dimethylglycine, also known as DMG, is a natural substance found in both plant and animal cells, and is derived from the amino acid glycine (see reference 1 under Clinical Summary para 1). As a supplement, it is purported to offer a number of health benefits, from enhancing physical performance to improving behavior in children with autism and attention deficit disorder. However, the evidence to support these claims is lacking, according to the Memorial Sloan Kettering Cancer Center (see reference 1 under Mechanism of Action).
How DMG Works
Meaning Of Dmg In Chemistry Test
The body produces DMG in the cells by breaking down choline (see reference 1 under Clinical Summary). In the body, it acts as an antioxidant and improves oxygenation of the cells (see reference 1 under Clinical Summary). The thought is that taking DMG as a supplement may further enhance oxygenation, which improves athletic performance (see reference 1 under Clinical Summary). It is also thought to act as a neurological stimulator, which is why it has gained popularity in the autism community (see reference 1 under Clinical Summary). According to an October 2009 review article on the use of complementary medicine in autism published in 'Child and Adolescent Psychiatric Clinics,' the two clinical trials testing the use of DMG on children with autism showed no positive effect or improvement in behavior (see reference 2 under DMG).
Safety Concerns
Meaning Of Dmg In Chemistry Terms
DMG is considered a safe and non-toxic substance, according to MSKCC (see reference 1 under Clinical Summary). If you're supplementing your diet with DMG, be sure to inform your doctor to monitor for any potential side effects or interactions. Additionally, while it's safe to take DMG, do not rely on it as a cure or treatment for any illness.