Measure 20cm3 of 005M sodium thisulphate into a 50cm3 glass beaker Place the beaker on a white piece of filter paper with ink mark X on it Measure 20cm3 of 01M hydrochloric acid solution using a 50cm3 measuring cylinder Put the acid into the beaker containing sodium thisulphate Immediately start off the stop watchclock Determine the time taken for the ink mark X to become invisible obscured when viewed from above Repeat the procedure by measuring different volumes of the acid and adding the volumes of the distilled water to complete table 1 Sample resultsTable 1