HHO gas

HHO gas is a purported "new form of water" created using "pulsed electrolysis" equipment. While "HHO" may look like a synonym for water (HOH), in papers by fringe physicist Ruggero Santilli, it is claimed that HHO is a unique form of matter, made up of "magnecules" of hydrogen gas (HH) connected to lone oxygen atoms (O) by "magnecular bonds".

Although Santilli's revolutionary theories about "hadronic mechanics" and "magnecules" are too cool for the lamestream scientific establishment, he still publishes articles about them in scientific journals that coincidentally happen to be owned and operated by himself. Naturally, he also wants to sell you things.

Flame temperature
Santilli states "The first experimental evidence supporting the magnecular structure of the HHO gas is its capability of instantly melting tungsten and bricks." These claims are repeated by companies that sell "HHO gas" torches: "HHO produces a 279 degree flame, that can sublimate tungsten in seconds at over 10,000 degrees."

Does tungsten become gas at 10,000 degrees? Yes. Tungsten's boiling point is 5,555°C, or 10,031°F. Does aiming a torch at tungsten and seeing smoke prove that the flame is burning at 10,000 degrees? Of course not. Does it imply that HHO gas is a new form of matter? Don't be silly.

The demonstrations of "sublimating" tungsten are actually done in air, and are therefore demonstrations of tungsten burning, not boiling. Tungsten burns easily in air (which is why light bulbs are filled with an inert gas such as argon), forming an oxidation layer of, which melts at only 1473°C and is blown away by the torch as smoke particles. Sublimating tungsten would have to be demonstrated in a vacuum.

Similarly, brick melts at temperatures from 1500°C to 1800°C.

An ordinary electrolyzer converts water into gas, a  mixture of oxygen gas O2 and hydrogen gas H2, which can then be burned, producing a flame with temperatures of 2600 to 3200°C,   plenty hot enough to melt bricks and burn tungsten. This is called a and, while interesting and useful, is not at all revolutionary and doesn't imply or require any new forms of matter to operate.

Water-powered cars
"HHO gas" is also cited in water-powered car hoaxes, in an attempt to explain how the devices circumvent the laws of thermodynamics. Converting water to hydrogen and oxygen, then burning it in an engine to produce water vapor and net energy output would be a perpetual motion device, so the claim is that pulsed electrolysis somehow splits water into hydrogen and oxygen without using as much energy as would be recovered by burning it. The obvious application of making infinite amounts of money by building power plants that produce energy out of nothing has somehow eluded the inventors.