178 NON-METALLIC ELEMENTS IN BINARY COMPOUNDS- Many binary compounds of non-metals with non-metals
are known, but such compounds usually can exist only out of
contact with water. For example, phosphorus trichloride is
completely hydrolyzed by water. Write the equation for this
reaction, and treating it as a metathesis, conclude which element
in the phosphorus trichloride is to be regarded as the positive
constituent. - Arrange the non-metals studied in this chapter in the order
of their activity as negative elements, (a) when they react in
aqueous solution, (b) when they react with "dry" substances. - Look up the heat of solution of hydrogen iodide and hydrogen
sulphide, and state how this factor is able to make iodine more
active than sulphur in aqueous solution, whereas sulphur is the
more active in the dry state.