Researchers are testing out different salt solutions to make a hot pack.

Question

Which experiment does the data collected suggest was most successful?

Experiment Salt used Temperate change
1 20g sodium bromide Raised 0.2°C
2 20g lithium fluoride Dropped 8.8°C
3 20g potassium chloride Dropped 10.6°C
4 20g lithium chloride Raised 42°C
5 20g potassium fluoride Raised 14.4°C

Answer 1

To determine which experiment was the most successful in making a hot pack, we should look for the experiment that resulted in the greatest increase in temperature, as a hot pack is intended to provide warmth.

Here are the temperature changes from each experiment:

1. Sodium bromide: Raised 0.2°C
2. Lithium fluoride: Dropped 8.8°C
3. Potassium chloride: Dropped 10.6°C
4. Lithium chloride: Raised 42°C
5. Potassium fluoride: Raised 14.4°C

The most successful experiment based on temperature change is Experiment 4, which used 20g of lithium chloride, resulting in a temperature increase of 42°C. This indicates it generated the most heat and would be the most effective for a hot pack.