In: Chemistry
Part A.3. the buret is filled with the NaOH titrant and the initial volume reading is immediately recorded without waiting the recommended 10-15 seconds. However in part B.1., the 10-15 seconds lapse does occur before the racing is made. Does this technique error result in an increase, decrease, or have no effect on the reported percent acetic acid on the vinegar? Expalin
The reaction of ionization of sodium hydroxide in water is an exothermic reaction. This will result in the increase in temperature of the NaOH solution. This will increase the evaporation of some amount of solvent.
After preparing NaOH solution, one should wait until the solution cools to room temperature. If needed and we can adjust the final volume by adding water.
Thus the actual concentration of NaOH will be slightly less than the NaOH titrant used without waiting for 10-15 seconds.
Thus obtained concentration of vinegar will be lower than the actual concentration since it did after waiting for 10-15 s.