hydrogen fluoride
- n a colorless poisonous corrosive liquid made by the action of sulphuric acid on calcium fluoride; solutions in water are hydrofluoric acid
hydrogen iodide
- n a colorless gas that yields hydroiodic acid in aqueous solution
hydrogen ion
- n a positively charged atom of hydrogen; that is to say, a normal hydrogen atomic nucleus
hydrogen ion concentration
- n the number of moles of hydrogen ions per cubic decimeter
hydrogen peroxide
- n a viscous liquid with strong oxidizing properties; a powerful bleaching agent; also used (in aqueous solutions) as a mild disinfectant and (in strong concentrations) as an oxidant in rocket fuels
hydrogen sulfide
- n a sulfide having the unpleasant smell of rotten eggs
hydrogenation
- n a chemical process that adds hydrogen atoms to an unsaturated oil
food producers use hydrogenation to keep fat from becoming rancid
hydrography
- n the science of the measurement and description and mapping of the surface waters of the earth with special reference to navigation
hydroiodic acid
- n an acid formed by aqueous solution of hydrogen iodide
hydrolith
- n a saltlike binary compound (CaH2) used as a reducing agent and source of hydrogen
hydrology
- n the branch of geology that studies water on the earth and in the atmosphere: its distribution and uses and conservation
hydrolysis
- n a chemical reaction in which water reacts with a compound to produce other compounds; involves the splitting of a bond and the addition of the hydrogen cation and the hydroxide anion from the water