Where Do Trees Come From? From Heaven or Earth?

Chemistry, Plants
Where do trees come from, from heaven or earth? This is not the philosophical discussion it might at first seem to be. Even in the Bible, heaven sometimes refers, not to the residence of the Almighty, but to that region of the atmosphere in which birds fly.¹ Do trees come from the soil or from the air? Most would probably say, “from the soil.” But is that the case? What are trees primarily made of? Largely they consist of cellulose and sugar, although there are smaller quantities of other substances. Cellulose is simply sugar molecules linked together with the loss of a single molecule of water between each sugar molecule. The molecules that build up a tree are carbon-based. There are traces of other substances, but only traces. For instance,…
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Spontaneous Human Combustion is Real

Forensics
It was a new concept for me, the idea that without flame, electric spark, or other external source of ignition, a human being could catch fire and be almost completely consumed. It is just too far out to be true. Or is it? Could spontaneous human combustion be real? Classically, three elements of combustion are recognized as necessary: suitable fuel, an oxidizing agent, and an appropriate source of spark or fire. The concept of spontaneity requires only fuel and usually oxidizer are present. Any source of ignition remains mysterious and unknown. The Typical SHC Scenario Typically, the individual who supposedly succumbs from spontaneous human combustion (SHC) is immobile and obese. The victim is likely to be female, though by no means is that always the case. [caption id="attachment_17404" align="alignright" width="240"]…
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Propane and Oxygen Combustion Question

Chemistry
[caption id="attachment_16612" align="alignright" width="480"] Propane[/caption] Problem: We desire to learn how much oxygen is needed to completely consume a certain quantity of propane gas. Our hydrocarbon and oxygen combustion question follows the basic reaction path, C3H8 + 5 O2 → 4 H2O + 3 CO2 If we have the following conditions: Temperature = 75 Celsius (348 Kelvin) Pressure = 720 / 760 mm = 0.95 atm Moles propane = 40.8 grams / 44.1 grams molecular weight = 0.93 moles How Much Oxygen to Burn the Propane? What volume of oxygen is needed to accomplish the burning of the 0.93 moles of the hydrocarbon? 5 times 0.93 moles of C3H8 burned = 4.65 moles of oxygen The ideal gas law reads: PV = nRT where P= the pressure, V= the volume, and…
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Leaded Gas: Any Ongoing Health Issue?

Health
[caption id="attachment_22186" align="alignright" width="440"] Tetraethyl Lead[/caption] What's special about leaded gas? And since it was eliminated, are there health issues in the environment because of it? For more than fifty years, internal combustion engines such as automobile engines have used a high compression ratio.” This means gas mixed with air, by carburetion or injection, has been severely squeezed by pistons in cylinders. Spark was then applied, igniting the mixture. This was done to increase power and save money. Enter Leaded Gas In order to prevent pre-ignition, one or more octane improving agents was added to the fuel. The most common of these, used since about 1924, was tetraethyl lead, (C₂H₅)₄Pb. Later, low compression engines became the standard, which minimized the need for octane improvement. This was because of recognizing that…
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