The substance X normally exists in a physical state which can flow easily but does not fill its vessel completely. It also turns anhydrous copper sulphate blue. When substance X is cooled excessively, it changes into a substance Y which has a fixed shape as well as a fixed volume. If, however, the substance X is heated strongly, it changes into a substance Z which has neither a fixed shape nor a fixed volume.
(a) Name the substances (i) X (ii) Y and (iii) Z.
(b) What is the process of conversion of X into Y known as ?
(c ) At which temperature X gets converted into Y ?
(d) What is the process of conversion of X into Z known as ?
(e) At which temperature X gets converted into Z ?

Answer

(a) (i) Water (ii) Ice (iii) Steam (b) Freezing (c ) `0^(@)C` (d) Boiling (or Vaporisation) (e) `100^(@)C`