Chemical Reactions Lab

The guiding question:  What How do you know a chemical reaction has taken place? Where is the evidence?

Your hypothesis: I think that the physical properties will change. As well as the temperature and position f the object also burning. I think when the two elements “states” stops changing then I think that the reactions is over. Also I think that you can see the evidence if you look at the original state of each element and then how it looks at the end of the experiment you can tell it has changed.

List of the Materials used:

-          Spatula

-          Graduated cylinder

-          Stirrer

-          Candle/matches

-          Thermometer

-          Goggles

-          Beakers/baby food jars

-          Na2Co3 (Sodium Carbonate)

-          CaCl2 (Calcium Chloride)

-          HCl (Hydrochloric Acid)

-          CuSu4 (Copper Sulfate (acid)

-          Aluminum Foil

-          Zinc Pieces

-          Baking Soda

-          Vinegar (Ascetic Acid)

-          Magnesium Tablets

-          Iodine

-          Starch

Data Table with ALL observations:

Reaction	Observation before reaction	Prediction	Observation during reaction	Observation after reactions
Baking soda  and vinegar	Clear powder Clear strong liquid	Bubble up	Starts exploding bubbling up foaming	Begins to relax and powder starting to settle at bottom of the test tube.
Sugar and heat	Sugar tinfoil bowl candle lit	Form caramel	Starts caramelizing	Dried up caramel that burned when relight the candle
Copper sulfate and sodium carbonate solution	Na2Co3 clear liquid CaCl2 blue liquid	No idea	Starting to blur water drops like smoke or powder	Powdery smoke forms as sediments at top of substance
Zinc piece and HCl	Zinc look like bone liquid clear	No idea	Looks like dissolving zinc piece	No more zinc, well there was except it looked more like a burnt bone. (sunk to bottom.)
Calcium chloride and sodium carbonate	Both clear liquids	Bubble up	Becomes translucent Color	Stays same as during reaction
Copper Sulfate and aluminum foil piece	Ball of tin foil  and blue liquid	Nothing is going to happen	Color of tinfoil began to change to a burnt bronzy auburn color	Once Reaction is complete the color of the tinfoil stayed the same as the color it was turning during the experiment.
Starch and Iodine (I2)	White powder light brown liquid	Unsure maybe change color?	Turns into Dark purple blackish color	Stays as black liquid.

Analysis of your results.  How do the results of each reaction compare with your prediction?  How did you know when each reaction was over?  What was the evidence of a chemical reaction in all results?  Were there any endothermic or exothermic reactions?  Were the products always the same as what you started with?  How do you know?  My prediction was pretty much correct, now that I have done the experiment I could of course add to it. I could tell that the reaction was over because some they combined to make a mixture and then that mixture never changed and then with other like the tin foil and sugar I could see that it was over when the tin foil started burning and the sugar had turned completely in to caramel J .

 

This is Zinc Reacting with HCl 

Conclusion:  Restate the guiding question and answer it.  Was your hypothesis correct in the beginning? Explain whether it was or was not.  How do you know if new substances were formed in each reaction?  Did the reactions ever come to an end? If so, why do you suppose that happens?  As for my predictions in my data table sometimes yes they were correct and sometime I was way off. For some reactions I was amazing at the change in the compound element and in others it was as expected. Such as with the Zinc reaction I surprised at how powerful the acid was when the reaction finished it just looked like a piece of burnt charcoal. I knew that the reaction was over because you could tell that the chemical was starting to get exhausted as it began to slow down toward the end of the reaction. What to me seemed like what was happening was that the element had used up all of its “energy” so to speak.

Further Inquiry:  Think about this experiment and the data you collected. Would you make any changes to the method/procedure? Do you have any further questions?  I wouldn’t change the way that we conducted this experiment, I think all things went pretty smoothly however it was sometimes hard to see the reaction what with the flask stands sometimes being in the way, but other than that I liked how the experiment was conducted and I definitely understood more about how different chemicals react together. One of my further questions would be; how drastic would the changed be if we added larger amount of each element, would some not work as well? Or would some be more effective? As for not work as well I think this might happen with the lighter and sugar experiment.