Confiez-nous votre commande

+(33) 5 61 73 60 14 | Nous contacter

Delta Microscopies

water is the first solvent, but what water are we talking?

par | Fév 9, 2020 | Technical blog, Tips and tricks | 0 commentaires

water is the first solvent, but what water are we talking?
A solvent is simply a substance that can dissolve other molecules and compounds, which are known as solutes. A homogeneous mixture of solvent and solute is called a solution, and much of life’s chemistry takes place in aqueous solutions, or solutions with water as the solvent.
Because of its polarity and ability to form hydrogen bonds, water makes an excellent solvent, meaning that it can dissolve many different kinds of molecules. Most of the chemical reactions important to life take place in a watery environment inside of cells, and water’s capacity to dissolve a wide variety of molecules is key in allowing these chemical reactions to take place.
Solvent properties of water

in the laboratory, we use different water grades which vary depending on how it is purified.
water is by far the most used product during our laboratory experiments for an example in electron microscopy, to prepare a buffer or a glutaraldehyde, osmium fixing solution,   not careful, nor we specify the type of water that we use although it often represents 99% of solution, distilled, deionized water, ultrapure and more.
by testing different waters you will be surprised by its major role in your fixation reactions, etc …
because the obvious things are often overlooked and we only deal with the nature of the product which represents 1% formaldehyde, osmium …..
I would like to draw your attention to the water which remains the first solvent, but not universal since it is not miscible with oils and the solubility of certain materials can be very limited.

the more the molecule takes its importance in electron microscopy and the more we must be vigilant on the type of water that we use, the ions play a preponderant role in all the various labeling reactions, conservation of structures, loss of cellular inclusions …

Thanks to its ability to dissolve a wide range of solutes, water is sometimes called the “universal solvent.” However, this name isn’t entirely accurate, since there are some substances (such as oils) that don’t dissolve well in water. Generally speaking, water is good at dissolving ions and polar molecules, but poor at dissolving nonpolar molecules. (A polar molecule is one that’s neutral, or uncharged, but has an asymmetric internal distribution of charge, leading to partially positive and partially negative regions.)
Water interacts differently with charged and polar substances than with nonpolar substances because of the polarity of its own molecules. Water molecules are polar, with partial positive charges on the hydrogens, a partial negative charge on the oxygen, and a bent overall structure. The unequal charge distribution in a water molecule reflects the greater electronegativity, or electron-greediness, of oxygen relative to hydrogen: the shared electrons of the O-H bonds spend more time with the O atom than with the Hs. In the image below, the partial positive and partial negative charges 
 
Because of its polarity, water can form electrostatic interactions (charge-based attractions) with other polar molecules and ions.
The polar molecules and ions interact with the partially positive and partially negative ends of water, with positive charges attracting negative charges (just like the + and – ends of magnets). When there are many water molecules relative to solute molecules, as in an aqueous solution, these interactions lead to the formation of a three-dimensional sphere of water molecules, or hydration shell, around the solute. Hydration shells allow particles to be dispersed (spread out) evenly in water.
 

Poster le commentaire

Votre adresse e-mail ne sera pas publiée. Les champs obligatoires sont indiqués avec *

0

Your Cart