show the conversions recorded after six hours from the three clay
samples activated with different molarity of sulphuric acid. In the graphs, the clay
activated with very dilute acid (0.1M) has very low conversion about 30%. Conversion
improved remarkably for the clay activated with medium strength acid (0.5M) up to 74%.
However, doubling the acid strength to 1M only added about 5% to the conversion with
0.5M. These results also show that the proton is the active agent of the activation. The
small difference in the conversion between 0.5M and 1M indicates that there is a limit
above which increase in the acid strength does not produce corresponding increase in
conversion. This may be the point where all the clay’s possible active sites have been
activated.