Question

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.

1. Name the substances (i) X (ii) Y and (iii) Z.
2.  What is the process of conversion of X into Y known as ?
3. At which temperature X gets converted into Y ?
4. What is the process of conversion of X into Z known as ?
5. At which temperature X gets converted into Z ?

Answer 1

1. the substances X, Y and Z are water, ice and steam, respectively.
2. The process of conversion of X into Y is known as freezing
3. At 0°C X is converted to Y.
4. Boiling or vaporisation is the name of the process of conversion of X to Z.
5. At 100°C X gets converted to Z.