The substance X normally exists in a physical state whichcan 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 X. (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 temperture X gets converted into Z ?

The substance X normally exists in a physical state whichcan flow easi

1.	The substance X normally exists in a physical state whichcan 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 X. (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 temperture X gets converted into Z ?
Answer» Solution :(a) The substance X is water since it turns anhydrous copper sulphate blue. (b) The substance Y is ice since water changes to ice upon EXCESSIVE cooling. The process of CONVERSION of X into Y is KNOWN as freezing. (c ) The TEMPERATURE called freezing point of water is `0^(@)C` or 273 K. (d) Water upon HEATING gets converted into steam (Z) and the process is known as boiling. (e ) X gets converted into Z at its boiling point temperature. It is `100^(@)C` or 373 K.