Hess's Law

What purpose is the calorimeter in this experiment?

To measure the heat released during a reaction

What does a negaative ΔH value indicate about the reaction?

The reaction is exothermic, releasing heat.

What purpose is the calorimeter in this experiment?

To measure the heat released during a reaction

What does a negaative ΔH value indicate about the reaction?

The reaction is exothermic, releasing heat.

What is Hess’s Law?

The total enthalpy change for a process is the sum of enthalpies of individual steps

Why is it necessary to dispose of the HCl solution after each trial?

To avoid contamination of the results in subsequent trials

What safety precautions is most relevant when handling HCl in this experiment?

Using gloves and goggles

What is the purpose of repeating trials in this experiment?

To average results for better accuracy

In Hess’s Law experiment, why is it necessary to add magnesium or magnesium oxide to the HCl solution in a calorimeter?

To accurately measure the heat given off by the reaction of either substance with HCl

If the calculated enthalpy change fir a reaction is higher than the known value. what could be a reason for discrepancy?

Incorrect recording of the final temperature

What happens to the temperature of the HCl solution in the calorimeter when magnesium is added?

It increases because the reaction is exothermic

What is the most probable reason we use 2 styrofoam cups instead of 1?

keep heat in the calorimeter for the most accurate readings