| Answer | Crossword Clue |
|---|---|
| hydrocyanic | denoting an acid (prussic acid) composed of hydrogen and cyanogen |
| hydrochloric | applied to an acid composed of hydrogen and chlorine, hydrogen chloride, still sometimes called muriatic acid |
| hydrobromic | applied to an acid composed of hydrogen and bromine, hydrogen bromide |
| barbituric | denoting an acid got from malonic acid and urea, a source of important sedatives |
