Design a Cold Pack / Hot Pack A chemical change is to alter the identity of a substance. Properties of these chemical changes include color change, gas formation, temperature change, precipitate formation, odor, and change in acidity. In the hot and cold pack experiment we found it to be a chemical reaction
An exothermic reaction is when the substance releases heat energy. An endothermic reaction is when the substance absorbs heat energy. In our experiment we created a cold pack. We indicated that the reaction for this experiment would be exothermic. We think this because exothermic is releasing the heat which would make it cold.
In our lab our guiding question was, which of the following substances would make an …show more content…
After we gathered our materials we measured 23 g of sodium nitrate and 200 mL of water. After measuring the water we put the water in the small bag. Then we took the initial temperature of the water, which was 23 degree celsius. Then, we put the 23g of sodium nitrate into the big bag. After that we put the small bag(unsealed) into the big bag(sealed). Then, we mixed the two substances together. Once we did that, our mixture started to turn colder. This reaction told us that our claim was correct. We took our final temperature at 19 degree celsius. We then made a data table to show all of the data we recorded during the experiment.
Just by seeing this data table you can already see so many things about our experiment. By looking at this graph you can tell that this was a cold pack experiment because exothermic means releasing heat energy. Also how much our temperature dropped.
In our experiment, we justified that sodium nitrate was a good substance to use in making a cold pack. Also that the cold pack was exothermic because it released heat energy. We know this because when the substances mixed it because cold. The substance dropped 4 degree celsius. We also know to only use 2 substances. If we used more than two the substances would have become a neutral and we would not know each substance reaction. From this experiment, our claim was proven correct. If you mix Sodium nitrate and water together it will create a cold