Melting-point Sentence Examples
They are mostly colourless liquids which boil without decomposition, or solids of low melting point.
It is to be noted that although the correlation of melting-point with constitution has not been developed to such an extent as the chemical significance of other physical properties, the melting-point is the most valuable test of the purity of a substance, a circumstance due in considerable measure to the fact that impurities always tend to lower the melting-point.
The overheating curve of rhombic sulphur extends along the curve AC, where C is the melting-point of monoclinic sulphur.
When zinc is placed on the lead (heated to above the melting-point of zinc), liquefied and brought into intimate contact with the lead by stirring, gold, copper, silver and lead will combine with the zinc in the order given.
It has in general one value for the powdery metal as obtained by reduction of the oxide in hydrogen below the melting point of the metal, another for the metal in the state which it assumes spontaneously on freezing, and this latter value, in general, is modified by hammering, rolling, drawing, &c. These mechanical operations do not necessarily add to the density; stamping, it is true, does so necessarily, but rolling or drawing occasionally causes a diminution of the density.Advertisement
The substance AuAl 2 is the most remarkable compound of two metals that has so far been discovered; although it contains so much aluminium its melting-point is as high as that of gold.
At intervals the current is interrupted, the cover removed, and the temperature of the vessel raised considerably above the melting-point of magnesium.
The freezing and melting point curves are exactly similar to theoretical curves of fig.
In fact, the molten iron is heated so far above its melting point that, instead of being run at once into pigs as is usual, it may, without solidifying, be carried even several miles in large clay-lined ladles to the mill where it is to be converted into steel.
In the hearth of the blast furnace the heat made latent by the fusion of the iron and slag must of course be supplied by some body which is itself at a temperature above the melting point of these bodies, which for simplicity of exposition we may call the critical temperature of the blast-furnace process, because heat will flow only from a hotter to a cooler object.Advertisement
The two great essential discoveries were first that the rapid passage of air through molten cast iron raised its temperature above the melting point of low-carbon steel, or as it was then called " malleable iron," and second that this low-carbon steel, which Bessemer was the first to make in important quantities, was in fact an extraordinarily valuable substance when made under proper conditions.
For making castings, especially those which are so thin and intricate that, in order that the molten steel may remain molten long enough to run into the thin parts of the mould, it must be heated initially very far above its melting-point, the Bessemer process has a very great advantage in that it can develop a much higher temperature than is attainable in either of its competitors, the crucible and the openhearth processes.
That removal progressively raises the melting-point of the metal, after line Aa of fig.
This temperature is somewhat different from the ordinary melting-point, the latter corresponding to atmospheric pressure, the former to the maximum vapour-pressure; and so we come to a third relation for polymorphism.
From this it follows that the stable form must have the higher melting-point, since at the melting-point the vapour of the solid and of the liquid have the same pressure.Advertisement
Rothe and Alexander Smith's interesting observations on sulphur, results have been obtained which tend to prove that the melting-point, as well as the appearance of two layers in the liquid state, correspond to unstable conditions.
This is not only due to the fact that they are mixtures of several glycerides, but also that even pure glycerides, such as tristearin, exhibit two melting-points, a so-called "double melting-point," the triglycerides melting at a certain temperature, then solidifying at a higher temperature to melt again on further heating.
In this way the metal, owing to its high conductivity and low specific heat as compared to that of water, is kept at a temperature far below its melting point if the water is renewed quickly enough.
The results show that the wetting of the lead-free alloys broadly follows that of tin-lead solder if allowance is made for the melting point.
This is increasingly the case, as lead-free soldering is beginning to be introduced to the industry with its accompanying higher melting point solders.Advertisement
The resulting surface is usually duller and less lustrous than that obtained by the use of molten zinc. Another method of forming a coating of zinc, known as "sherardizing," was invented by Sherard CowperColes, who found that metals embedded in zinc dust (a product obtained in zinc manufacture and consisting of metallic zinc mixed with a certain amount of zinc oxide) and heated to temperatures well below the melting point of zinc, become coated with a layer of that metal.
The data are tabulated at intervals of 10 K in the range from the melting point to 0.8 of the critical temperature.
Make sure if you choose these that you don't use them near your stove; they have an extremely low melting point and can be damaged by everyday cooking.
Soy wax does best for container candles because it has a low melting point and is not very hard.
Since soybean oil lowers the melting point of the candle, the candle burns cooler and has a faster scent dispersion.Advertisement
It's a great idea to use a thermometer instead of just guessing or going by what you think the melting point of the wax you're using is.
Soy candles have a lower melting point then paraffin wax candles.
Tallow candles have a low melting point and give off a rather unpleasant odor, so these candles weren't anything like the ones we enjoy today.
The low melting point caused the candles to burn quickly, and the wax ran down the sides, pooling in large masses.
The addition of soybean oil lowers the melting point of the candle.
Tungsten aka wolfram is a heavy element with an atomic number of 74 and has the highest melting point of all elements.
The cadmium molecule, as shown by determinations of the density of its vapour, is monatomic. The metal unites with the majority of the heavy metals to form alloys; some of these, the so-called fusible alloys, find a useful application from the fact that they possess a low melting-point.
Paraffin wax is tested for melting-point (or setting-point), and the semi-refined product is further examined to ascertain the percentage of oil, water and dirt present.
Certain regularities attend the corresponding property of the melting-point.
A bath, even of very impure zinc, is allowed to stand at about the temperature of the melting-point of the metal for forty-eight or more hours, whereupon the more easily oxidizable impurities can be largely removed in the dross at the top, the heavier metals such as lead and iron settling towards the bottom.
It is then separated in a centrifugal machine, the low melting-point impurities are removed by means of hot water, and the residue is finally hot-pressed.
Japanese bronze is well suited for castings, not only because of its low melting-point, great fluidity and capacity for taking sharp impressions, but also because it has a particularly smooth surface and readily develops a fine patina.
This agrees with the well-known fact that the presence of an impurity in a substance depresses its melting-point.
The mixture C has a lower freezing or melting point than that of any other mixture; it is called the eutectic mixture.
Much information as to the nature of an alloy can be obtained by placing several small ingots of the same alloy in a furnace which is above the melting-point of the alloy, and allowing the temperature to fall slowly and uniformly.
The dry process is more frequently practised, for the easy reducibility of the oxide and sulphide, together with the low melting-point of the metal, renders it possible to effect a ready separation of the metal from the gangue and impurities.
Thus in two ways at least a constant melting point can be obtained in a two-component system.
In 1856 Bessemer not only invented his extraordinary process of making the heat developed by the rapid oxidation of the impurities in pig iron raise the temperature above the exalted melting-point of the resultant purified steel, but also made it widely known that this steel was a very valuable substance.
By rapidly stirring molten iron oxide into molten pig iron in a furnace shaped like a saucer, slightly inclined and turning around its axis, at a temperature but little above the melting-point of the metal itself, the phosphorus and silicon are removed rapidly, without removing much of the carbon, and by this means an extremely pure cast iron is made.
Its melting-point is below that of silver.
When heated above its melting-point, it yields ammonia, cyanuric acid, biuret and ammelide.
He proceeds to calculate from this expression the difference of vapour-pressures of ice and water in the immediate neighbourhood of the melting-point, but does not observe that the vapour-pressures themselves may be more accurately calculated for a considerable interval of temperature by means of formula (23), by substituting the appropriate values of the latent heats and specific heats.