When carrying out experiment in the laboratory to investigate physical changes, absolute measurement is usually not needed. For instance, one can just take a little sample of sodium chloride and dissolve it in water to demonstrate physical change. But for other experiments, such as the measurement of the catalase enzyme activity in a liver tissue. Careful measurements have to be made when preparing the chemicals that will be used in the experiment.
1.3g Sn X 118.71g Sn/ 1 mole Sn= 154.32g Sn
