We have just completed the lab call "Chemistry in a bag." The first thing we did was grab the bag and added one scoop of sodium bicarbonate (baking soda) and one scoop of calcium chloride into one side of the baggie. One the other side, we filled a pipet with phenol red and put in on the other side of the baggie, not letting the two mixtures touch. We sealed the baggie and mixed the ingredients. The color turned magenta, and then a deep to bright yellow. The baggie also began to increase in temperature as the mixture was shaken. We let the bag sit and the bag filled with air and popped. The mixture smelled similar to rubbing alcohol.
To test which combinations created each reaction we tested one scoop of sodium bicarbonate and one pipet of phenol red. The experiment resulted in showing that the phenol red mixed with sodium bicarbonate did not cause the heat or the yellow color. The temperature did not change, but the phenol red was cold going into the baggie. The mixture had a gritty feeling and a reddish color.
The next mixture we tested was a pipet full of phenol red and one scoop of calcium chloride. This resulted in the heat of the experiment. The results showed that the two mixed together create a magenta color, but not the yellow color of the starting experiment.
WEe mixed one scoop of calcium chloride, one scoop of sodium bicarbonate, and one pipet of water. The mixture became warm and produced a gas that filled the baggie.
We then mixed one pipet of phenol red, one pipet of water, and calcium chloride. The mixture became hot and turned a deep magenta color.
We mixed one pipet of phenol red, one pipet of water, and one scoop of sodium bicarbonate. The mixture became cold and turned a red-magenta color.
We next tested one scoop of calcium chloride and one pipet of water. This mixture resulted in the heat of the experiment of all three mixtures. The color was a milky white and the calcium chloride didn't dissolve. The color didn't turn red nor yellow. This also didnt create the air that was prdouce in the first experiment.
We mixed one pipet of phenol red, one scoop of sodium bicarbonate, and one scoop of calcium chloride. This resulted in a warm temperature that eventually turned cold. It also produced gas and turned yellow.
POST LAB QUESTIONS
1. I can say for certain that one fator to the heat was the calcium chloride. In both experiments, the phenol red/water and the calcium chloride both produced heat. It seems as though all calcium chloride needs is a liquid to increase in temperature.
2. The phenol red mixed with sodium bicarbonate did not have a temperature increase. The mixture did become lower than room temperature after the phenol red was added, but I think the phenol red was colder that room temperature. Water mixed with sodium bicarbonate did result in a temperature decrease.
3. The color in the overall reaction changed dramatically. At first the mixture turned magenta, but after it was shaken up it turned a yellow-ish color. In the controlled experiments, the mixture not including water, resulted in the yellow color of the experiment.
4. No. For example: the phenol red and the calcium chloride mixed together created a temperature change (heat) and color change (magenta) all without gas bubbles. The first experiment did create gas bubbles though.
5. We tested both substances with water, with phenol red, and with no liquid at all. The reaction that happened with no water, resulted in the yellow color, the gas, and the heat.
6. The evidence suggests that it is a new substance because the color and the temperature. Neither the color or the temperature would've happened with out combining all of the necessary items.
7. Mix calcium chloride with a different liquid to test what the reaction is.
8. This doesn't always mean a chemical reaction has occured because the temperature of the liquid plays a part in the temperature.
No comments:
Post a Comment