Watch the following video of the calcium chloride dissolving in water and record the temperature during

Question

reaction every 10 seconds.

10 s 20 s 30s 40s 50s
21.3 Celsius
1. Did the temperature continually rise during the reaction?
2. Is this considered an exothermic or endothermic reaction?
3. Describe an idea of how to maximize the change in energy.

Answer 1

1. Did the temperature continually rise during the reaction?

   • Based on the data you provided (21.3°C at the first measurement), it seems that you only mentioned a single temperature reading. In many cases of dissolving calcium chloride in water, however, the temperature typically drops during the reaction. If you were to measure every 10 seconds and recorded a decrease in temperature, then the temperature would not be continually rising.

2. Is this considered an exothermic or endothermic reaction?

   • The dissolution of calcium chloride in water is considered an endothermic reaction, as it absorbs heat from its surroundings, resulting in a temperature drop in the solution.

3. Describe an idea of how to maximize the change in energy.

   • To maximize the change in energy in this reaction, you could use a larger quantity of calcium chloride to increase the extent of dissolving, which would amplify the temperature drop observed. Additionally, using distilled water at a slightly elevated temperature before adding the calcium chloride could also enhance the effect, as there would be a greater temperature difference between the dissolved salt and the water, potentially leading to quicker dissolution and more pronounced heat absorption. Furthermore, stirring the solution continuously could help evenly distribute the salt and promote better interaction between the calcium chloride and water, maximizing the energy change.