Term of the Day
The molar massThe mass of a mole of substance; the same as molecular weight for molecular substances. of a substanceA material that is either an element or that has a fixed ratio of elements in its chemical formula. divided by the chemical combining power of the substance. For example, in the case of an acidIn Arrhenius theory, a substance that produces hydrogen ions (hydronium ions) in aqueous solution. In Bronsted-Lowry theory, a hydrogen-ion (proton) donor. In Lewis theory, a species that accepts a pair of electrons to form a covalent bond. the molar mass is divided by the number of available hydrogen ions because a triprotic acid like H3PO4 has three times the chemical combining power of a monoprotic acid like HCl.