Question

If you went past the endpoint when performing the titration of lithium hydroxide with hydrochloride acid, how would that error affect your value for the atomic weight of lithium? Explain. (Hint: For one of your trials plug in a volume of Hcl that is larger than what you actually used does this calculated atomic weight of Li get bigger or smaller when you do this?)

Answer 1

While performing this titration , if we went past the end point by adding more amount of HCl into the solution while determining for the atomic weight of lithium , the calculated weight of Li will get bigger.

This is because the concentration of LiOH in the titration is fixed. So if the unknown HCl has been increased by error , it will give false bigger amount of product formed. Since the reaction is equimolar , we assume there is no reactant in the solution left unused , but there actually is , i.e. HCl , the higher atomic weight of Li will be observed.