chem whatarethemechanismsofchemicalchange

Reactivity 3.1.3 - some species can act as both Brønsted-Lowry acids and bases

amphiprotic substances can act as both Brønsted-Lowry acids and bases

  • to act as an acid: they must be able to dissociate and release
  • to act as a base: they must be able to accept , must have lone pair of electrons

amphoteric substances can react with both acids and bases

moving left to right across a period, the oxides transition from basic metal oxides through amphoteric oxides, to acidic oxides

nitrogen and sulfur form several different oxides, known as and , released from the burning of fossil fuels.

these oxides can react with moisture in the atmosphere to form weak acids and react further to form strong acids.

eg:

this lowers the causing acid rain

challenge questions
  1. at ambient temperature, the polyatomic ion may not be considered truly amphiprotic as its basic properties dominate - losing in solution is unlikely due to the instability of in water. however, when a metal hydroxide such as magnesium hydroxide is heated, it decomposes as follows:
derive the ionic form of this reaction to analyse how the hydroxide ion is showing amphiprotic behaviour here