When preparing standard 0.1 mol L-1 hydrochloric acid there is uncertainty associated with balances and 250 mL volumetric flask. The uncertainty associated with balancing could be reduced by using more precise scales. Greater uncertainty is associated with the volumetric flask. This could be reduced by using more precise glassware. When standardizing against anhydrous sodium carbonate, there is uncertainty associated with the equilibrium. Again, a more precise balance would reduce uncertainty. The factor contributing most to the uncertainty is the burette, which could be reduced by better quality glassware. The uncertainty was reduced by the fact that all experiments took place in the same environment, so there was no difference in humidity and temperature. The same scale was used for each measurement in the experiment. Using an eyedropper to ensure the meniscus was as accurate as possible reduced uncertainty. The titration was repeated 5 times reducing the random error that could have been associated with the