A student rinsed the calorimeter cup with water but did not dry it before determining δh°rxn (3); consequently, a significant amount of water was present in the cup before the hydrochloric acid was poured in. how would this error affect the final result for the heat of formation of magnesium oxide?

Calorimetry is a laboratory procedure that determines the specific heat capacity of a certain sample placed inside the calorimeter. A calorimeter is an insulated vessel where combustion of the sample happens. If the HCl sample is contaminated with water, then the specific heat that would be determined later is more than the empirical data for the specific heat capacity of HCl. The heat capacity for water would be added, instead of HCl alone.