Search results
Results From The WOW.Com Content Network
Paraffin wax (or petroleum wax) is a soft colorless solid derived from petroleum, coal, or oil shale that consists of a mixture of hydrocarbon molecules containing between 20 and 40 carbon atoms. It is solid at room temperature and begins to melt above approximately 37 °C (99 °F), [ 2 ] and its boiling point is above 370 °C (698 °F). [ 2 ]
The best-known animal wax is beeswax, used in constructing the honeycombs of beehives, but other insects also secrete waxes. A major component of beeswax is myricyl palmitate which is an ester of triacontanol and palmitic acid. Its melting point is 62–65 °C (144–149 °F). Spermaceti occurs in large amounts in the head oil of the sperm whale.
The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at a standard pressure such as 1 atmosphere or 100 kPa.
The wax scales are about three millimetres (0.12 in) across and 0.1 mm (0.0039 in) thick, and about 1100 are needed to make a gram of wax. [3] Worker bees use the beeswax to build honeycomb cells. For the wax-making bees to secrete wax, the ambient temperature in the hive must be 33 to 36 °C (91 to 97 °F).
With a melting point of 68.5–72.5 °C (155–162 °F), candelilla wax consists of mainly hydrocarbons (about 50%, chains with 29–33 carbons), esters of higher molecular weight (20–29%), free acids (7–9%), and resins (12–14%, mainly triterpenoid esters). [2] The high hydrocarbon content distinguishes this wax from carnauba wax. [3]
Boiling point (°C) K b (°C⋅kg/mol) Freezing point (°C) K f (°C⋅kg/mol) Data source; Aniline: 184.3 3.69 –5.96 –5.87 K b & K f [1] Lauric acid: 298.9 44 –3.9
in watchmaking, due to its low melting temperature (about 80–100 °C (176–212 °F)), shellac is used in most mechanical movements to adjust and adhere pallet stones to the pallet fork and secure the roller jewel to the roller table of the balance wheel. Also for securing small parts to a 'wax chuck' (faceplate) in a watchmakers' lathe. [52]
A Assuming an altitude of 194 metres above mean sea level (the worldwide median altitude of human habitation), an indoor temperature of 23 °C, a dewpoint of 9 °C (40.85% relative humidity), and 760 mmHg sea level–corrected barometric pressure (molar water vapor content = 1.16%).