| # | Clue | Answer As Given | Value | Round | Category | Air Date | Show |
|---|---|---|---|---|---|---|---|
| (Sarah of the Clue Crew burns one in from Volcanoes National Park, Hawaii.) Volcanic fumes can be hazardous to your health: they contain sulfuric acid, glass particles & this, HCl | hydrochloric acid | $2,000 | DJ | SCIENCE POTPOURRI | 2004-06-17 | #4569 | |
| Sometimes known as muriatic acid, it's a solution of hydrogen chloride in water | hydrochloric acid | $300 | J | SCIENCE | 1987-05-26 | #642 |