An Alternative to the Flame Test: Using Inexpensive Tesla Coils to Produce the Emission Spectra of Metal Salts

Abstract

High-voltage plasma arcs from solid-state Tesla coils were used to produce characteristic atomic emissions of various metals. The colored arcs produced were highly visible and vibrant, making for a spectacularly engaging demonstration for groups of varying sizes. The demonstration used an inexpensive solid-state Tesla coil to generate low-current, high-frequency, high-voltage electrical arcs that atomize and excite metal salts within a constructed vessel, eliciting the associated characteristic spectral emissions as a result. The demonstration serves as a valuable, accessible, and safer alternative to solvent-based demonstrations. Specifically, this method can challenge student misconceptions associated with the traditional flame test due to the flameless nature of the arcs. The demonstration also introduces the mechanisms underpinning inductively coupled plasma atomic emission spectrometers, which are commonplace in analytical laboratories. The high-frequency nature of the Tesla coil arcs reduces the risks of burns and can facilitate further discussions regarding plasma, states of matter, electron behavior, electricity, and alternate forms of spectroscopy.

Multipurpose DIY Spectrophotometer for Teaching Analytical Chemistry

“…AES is a technique commonly used to probe the energy states of an element or compound by analyzing the light emitted from an excited atom. A recent publication demonstrated the use of a Tesla coil as a source of energy to excite the electrons, 9 displaying different color spectra with different chemical compounds. We adopted a similar Tesla coil design and further developed the setup into a fully functional AES system.…”