Beer Bottle Condensation: What Forces Produce Droplets?

philosophy, Physics
Dan asked us¹... "My question concerns condensation droplets. What dictates how droplets form, then combine with each other? When you blow warm breath onto a cool surface, at first nothing appears to happen. Keep it up and droplets appear. These small droplets merge into bigger droplets. What physical laws dictate how this occurs? Also, what role does gravity play on vertical surfaces such as a chilled bottle of beer, producing tiny rivulets of moisture running down the sides?" Initial Commentary The answer, which follows, although it has some basis in well-known physical principles, depends in part upon observation, mental visualization, and (finally) blatant speculation. This is an interesting procedure, since so many of life’s mundane occurrences are in reality quite fascinating when closely examined. Initial Condensation We breathe in and…
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Heavy Water –vs.– Regular Water

Chemistry, Physics
[caption id="attachment_14687" align="alignright" width="440"] Heavy Water & Water - Image by Author.[/caption] Hydrogen exists as three varieties or isotopes: protium, deuterium, and tritium. Heavy water, or deuterium oxide (D₂O) is the same compound as ordinary or tap water (H₂O) with one structure difference. Most of the hydrogen atoms in tap water have zero neutrons in their centers, or nuclei. On the other hand, every atom of deuterium contains precisely one neutron. We will not discuss tritium, with its one proton and two neutrons. [caption id="attachment_14693" align="alignright" width="400"] Protium & Deuterium Hydrogen - NASA[/caption] A Closer Inspection of Hydrogen Isotopes The mass of an atom is determined by the nucleus. Since the weight of a proton and that of a neutron are nearly identical, deuterium atoms have a mass essentially double…
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Polymeric Water Clusters

Chemistry, Physics
[caption id="attachment_12642" align="alignright" width="480"] Ice floating in water. Image Morguefile by larryfarr[/caption] Polymeric water clusters? What are they? And what do they have to do with life? There’s no point in discussing how important water is to life. It is the single most necessary compound for the existence and survival of human, animal, and plant life. Why Special? What makes water special is its unusual behavior. Typical of liquids, as water approaches freezing, its density increases. Yet just before freezing, it suddenly decreases. This is why ice floats. Once it forms, ice insulates the water beneath it. It prevents large bodies of water from freezing solid. How? Hydrogen bonding. To understand hydrogen bonding, we must first consider the shape of the water molecule. Geometry of a Water Molecule A water…
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The Dipolar Molecule Water – Mickey the Dipole

Chemistry
[caption id="attachment_16242" align="alignright" width="440"] The bent water molecule manifests uneven charge distribution. Image by Qwerter CC-by-SA 3.0.[/caption] Mickey the Dipole? Everyone knows H₂O is the chemical formula for water. H stands for hydrogen. O stands for oxygen. The water molecule is made from two atoms of hydrogen and one atom of oxygen. Hydrogen atoms have one proton and one electron. Ordinary oxygen atoms have eight protons and eight neutrons and eight electrons. For the purposes of this discussion, we can forget the protons and the neutrons. Oxygen has a thirst for electrons. Hydrogen is "happy" to give up its electron. The reaction of hydrogen with oxygen (each of which exist as a pair) is, 2 H2 + O2 → 2 H2O The hydrogen parts are positive (H⁺). The oxygen part…
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Transition from Ice to Water to Vapor

Physics
[caption id="attachment_5490" align="alignright" width="440"] Hydrogen Bonding - CCA SA 3.0 Unported by Magasjukur2[/caption] The transition from ice to water to steam. What happens? A block of ice has a temperature well below freezing and is warmed gradually. It reaches above the boiling point. What transitions occur along the way? What are the processes? Transition: Solid to Liquid At first, the heat supplied simply increases the temperature of the ice. The temperature of the surface is somewhat warmer than the ice inside. It takes time for heat to penetrate. Eventually, the outer layer of the ice reaches the melting point. The outside ice melts first—then the inner ice. [caption id="attachment_5491" align="alignleft" width="220"] Melting Ice[/caption] During melting, the heat energy is spent breaking the stiff hydrogen bonds. None of it is spent…
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On the Nature of Azeotropes

Chemistry
[caption id="attachment_4850" align="alignright" width="440"] Russian Vodka Still[/caption] Definition: azeotropes are a specific mixture of compounds that boil together as if they were a single substance, at constant temperature. Individual Boiling Points In most instances, liquids boil as pure substances at a specific temperature. It is this property that allows boiling (as a physical property) to be used as a means of separation. For instance, an ester may be produced by reacting an organic acid and an alcohol. The resultant ester may usually be separated by boiling from excess alcohol or excess acid. Yet, Occasionally In some instances, however, as for example in the case of ethyl alcohol and water, there may be a mixture that distills over, instead of a pure substance. Thus a “mixture” of approximately 95.6% alcohol and…
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