Calorimetry and Heats of Solution

Elise introduces an experiment on calorimetry to determine heats of solution. The setup involves a coffee cup calorimeter, which acts as an insulator. The experiment includes determining the calorimeter's heat capacity by measuring temperature changes when hot water is added to room temperature water. Additionally, the heats of solution for anhydrous sodium acetate and sodium acetate trihydrate are determined by observing temperature changes as the salts dissolve. Proper measurement techniques and data recording are emphasized throughout the experiment.

What is the primary purpose of using a coffee cup calorimeter in this experiment?

• To measure the volume of liquids

• To weigh the salts

• To act as an insulator for heat exchange

• To stir the solution

How is the heat capacity of the calorimeter determined?

• By measuring the mass of the calorimeter

• By comparing the heat lost by hot water to the heat gained by cool water

• By observing the color change in the solution

• By calculating the density of the water

Which two salts are used to determine the heats of solution in this experiment?

• Sodium chloride and potassium chloride

• Anhydrous sodium acetate and sodium acetate trihydrate

• Calcium carbonate and magnesium sulfate

• Sodium bicarbonate and sodium sulfate

Why is it important to close the salt containers immediately after measuring?

• To avoid contamination with other chemicals

• To prevent the salts from reacting with each other

• To maintain the temperature of the salts

• To prevent the anhydrous salt from absorbing moisture from the air

What is the initial step when adding salt to the calorimeter?

• Add the salt all at once and close the calorimeter

• Pour the salt slowly over time

• Heat the salt before adding

• Measure the salt's pH level

How should the calorimeter be handled to aid in the dissolution of the salt?

• Leave it undisturbed

• Heat it with a Bunsen burner

• Swirl it gently on the desktop

• Shake it vigorously

What should be done after completing the measurement with one mass of salt?

• Heat the solution to evaporate water

• Add ice to cool the solution

• Dispose of the solution and dry the calorimeter

• Add more salt to the same solution

How many different masses of each salt are used in the experiment?

• Five

• Two

• Three

• Four

What should students look up as part of their pre-lab questions?

• The accepted values of the heats of solution

• The boiling point of water

• The density of the salts

• The chemical formula of the salts

Which salt is expected to cause a temperature increase upon dissolving?

• Sodium acetate trihydrate

• Neither salt

• Anhydrous sodium acetate

• Both salts