In the lab, you plan to carry out a calorimetry experiment to determine ∆_rH for the exothermic reaction of Ca(OH)₂(s) and HCl(aq). Predict how each of the following will affect the calculated value of ∆_rH. (The value calculated for ∆rH for this reaction is a negative value so choose your answer from the following: ∆_rH will be too low [that is, a larger negative value], ∆_rH will be unaffected, ∆_rH will be too high [that is, a smaller negative value].) 

(a) You spill a little bit of the Ca(OH)₂ on the benchtop before adding it to the calorimeter.

(b) Because of a miscalculation, you add an excess of HCl to the measured amount of Ca(OH)₂ in the calorimeter.

(c) Ca(OH)₂ readily absorbs water from the air. The Ca(OH)₂ sample you weighed had been exposed to the air prior to weighing and had absorbed some water.

(d) After weighing out Ca(OH)₂, the sample sat in an open beaker and absorbed water.

(e) You delay too long in recording the final temperature. 

(f) The insulation in your coffee-cup calorimeter was poor, so some energy as heat was lost to the surroundings during the experiment.

(g) You have ignored the fact that energy as heat also raised the temperature of the stirrer and the thermometer in your system.