Sodium chlorid + Sulphuric = Sodium + Hydrochloric
(common salt) acid Sulfate acid
The reader will observe that there are as many parts of each element on
the right as on the left-hand side of the = mark. Two parts of common
salt yield two parts each of sodium (Na) and chlorin (Cl). The sodium
appears as _Na_ in the sodium sulfate, and the chlorin as _Cl_ in the
two parts of hydrochloric acid.
This method of expressing chemical action by these equations may be
somewhat confusing at first to those who have not studied chemistry, but
it is best to have all such become familiar with them that they may have
the further benefit of understanding the general terms of chemistry.
Hydrochloric acid gives up its hydrogen when brought into contact with
certain metals like iron, zinc, etc., and takes up these metallic
elements in place of the hydrogen. Thus zinc and hydrochloric acid give
zinc chlorid and hydrogen.