Molecular-weight Sentence Examples

Hantzsch (Ber., 1901, 34, p. 3337) has shown that in the action of alcohols on diazonium salts an increase in the molecular weight of the alcohol and an accumulation of negative groups in the aromatic nucleus lead to a diminution in the yield of the ether produced and to the production of a secondary reaction, resulting in the formation of a certain amount of an aromatic hydrocarbon.

Gerhardt found that reactions could be best followed if one assumed the molecular weight of an element or compound to be that weight which occupied the same volume as two unit weights of hydrogen, and this assumption led him to double the equivalents accepted by Gmelin, making H= 1, 0 =16, and C = 12, thereby agreeing with Berzelius, and also to halve the values given by Berzelius to many metals.

From a study of the free elements Cannizzaro showed that an element may have more than one molecular weight; for example, the molecular weight of sulphur varied with the temperature.

This view was modified by Liebig, who regarded ether as ethyl oxide, and alcohol as the hydrate of ethyl oxide; here, however, he was in error, for he attributed to alcohol a molecular weight double its true value.

Kopp, begun in 1842, on the molecular volumes, the volume occupied by one gramme molecular weight of a substance, of liquids measured at their boiling-point under atmospheric pressure, brought to light a series of additive relations which, in the case of carbon compounds, render it possible to predict, in some measure, the cornposition of the substance.

In practice it is generally more convenient to determine the density, the molecular volume being then obtained by dividing the molecular weight of the substance by the density.

We now proceed to discuss molecular heats of compounds, that is, the product of the molecular weight into the specific heat.

He introduced the idea of comparing the refractivity of equimolecular quantities of different substances by multiplying the function (n-1)/d by the molecular weight (M) of the substance, and investigated the relations of chemical grouping to refractivity.

It may be generally inferred that an increase in molecular weight is accompanied by a change in colour in the direction of the violet.

Obviously equimolecular surfaces are given by (Mv) 3, where M is the molecular weight of the substance, for equimolecular volumes are Mv, and corresponding surfaces the two-thirds power of this.

Now the value of K, -y being measured in dynes and M being the molecular weight of the substance as a gas, is in general 2.121; this value is never exceeded, but in many cases it is less.

No method has yet been devised by which the molecular weight can be ascertained.'

P 1 greater than P2, if the molecular weight of A be much less than that of B, then it is obvious that the ratio M 1 P 1 /M 2 P 2 need not be very great, and hence the less volatile liquid B would come over in fair amount.

These con-, ditions pertain in cases where distillation with steam is successfully practised, the relatively high volatility of water being counterbalanced by the relatively high molecular weight of the other component; for example, in the case of nitrobenzene and water the ratio is I to 5.

This subject owes its importance in modern chemistry to the fact that the vapour density, when hydrogen is taken as the standard, gives perfectly definite information as to the molecular condition of the compound, since twice the vapour density equals the molecular weight of the compound.

A quantity of gas measured by its molecular weight in grammes when confined in a volume of one litre exerts a pressure of 22.2 atmospheres, and thus the osmotic pressure of a dilute solution divided by its concentration in gramme-molecules per litre has a corresponding value.

In the vapour pressure equation p - p' = Pa/p, we have the vapour density equal to M/v 1, where M is the molecular weight of the solvent.

Jochem (Ber., 1901, 34, p. 3337), who arrived at the conclusion that the normal decomposition of diazonium salts by alcohols results in the formation of phenolic ethers, but that an increase in the molecular weight of the alcohol, or the accumulation of negative groups in the aromatic nucleus, diminishes the yield of the ether and increases the amount of the hydrocarbon formed.

Cryoscopic determinations of its molecular weight show that it is H 2 0 2.

The cases of mutual transformation are generally characterized by the fact that in the compound of higher molecular weight no new links of carbon with carbon are introduced, the trioxymethylene being O CH2-0 CH 2 whereas honey-sugar correg probably C C H 2 -0% sponds to CH 2 0H [[Choh Choh Choh Choh Cho]], each point representing a linking of the carbon atom to the next.

According to Rabuteau the toxic properties of the higher alcohols increase with their molecular weight and boiling point.

The Well Known Experiments Of Regnault And Wiedemann On The Specific Heat Of Gases At Constant Pressure Agree In Showing That The Molecular Specific Heat, Or The Thermal Capacity Of The Molecular Weight In Grammes, Is Approximately Independent Of The Temperature And Pressure In Case Of The More Stable Diatomic Gases, Such As 112,02, N2, Co, &C., And Has Nearly The Same Value For Each Gas.

The most important apparent exceptions to Raoult's law in dilute solutions are the cases, (I) in which the molecules of the dissolved substance in solution are associated to form compound molecules, or dissociated to form other combinations with the solvent, in such a way that the actual number of molecules n in the solution differs from that calculated from the molecular weight corresponding to the accepted formula of the dissolved substance; (2) the case in which the molecules of the vapour of the solvent are associated in pairs or otherwise so that the molecular weight m of the vapour is not that corresponding to its accepted formula.

It exists in two forms, one having the formula P 4 5 10, and the other a lower molecular weight.

It also dissolves in alcohol and ether; boiling point determinations of the molecular weight in these solutions point to the formula FeCl3.

The physical properties of the alcohols exhibit a gradation with the increase of molecular weight.

Do not use full-dose low molecular weight heparin or other new anticoagulants without seeking advice first.

The gel permeation chromatography (GPC) measurements show that the molecular weight profile is only changed slightly.

It consists of high molecular weight hydrocarbons and minor amounts of sulfur and nitrogen compounds.

She was treated with high dose oral steroids, low molecular weight dextran and vasodilators with benefit.

The molecular weight of the native protein determined from sedimentation equilibrium in buffers containing from 50 to 200 mM KCl is 20,000.

Samples were then run on an ABI 377 gene scan analysis gel with an internal molecular weight marker.

Molecular shape can be estimated, when the absolute molecular weight (MW) is known.

Polypropylene can be made auxetic by compacting ultra high molecular weight PP powder, with a particle size of 30 to 120 microns.

The fibers are made from ultra high molecular weight polyethylene with an extremely high molecular mass.

The specific low molecular weight chondroitin sulfate, exclusive to Cosequin, is the most pure form available on the market.

Partial anticoagulation with low molecular weight heparin (LMWH) or low dose warfarin (INR 1.5) are relative contraindications.

Typically, the molecular weight is measured using static light scattering.

Boiling and freezing-point determinations of the molecular weight in solution indicate the formula S8.

Laurent generally agreed, except when the theory compelled the adoption of formulae containing fractions of atoms; in such cases he regarded the molecular weight as the weight occupying a volume equal to four unit weights of hydrogen.

In all cases it is usual to represent substances by formulae which to the best of our knowledge express their molecular composition in the state of gas, and not merely the relative number of atoms which they contain; thus, acetic acid consists of carbon, hydrogen and oxygen in the proportion of one atom of carbon, two of hydrogen, and one of oxygen, but its molecular weight corresponds to the formula C211402, which therefore is always employed to represent acetic acid.

The actual values of the topic parameters can then readily be expressed in terms of the elements of the crystals (the axial ratios and angles), the density, and the molecular weight (see Groth, Physikalische Krystallographie, or Chemical Crystallography).

Polyethylene is a plastic with a very high molecular weight which is highly resistant against wear and tear.

Immunoglobin A-A sugar protein with a high molecular weight that acts like an antibody and is produced by white blood cells during an immune response.