Detecting Signs of Chemical Change

The experiment is to observe a variety of chemical reactions and to identify patterns in

Purpose: The purpose of this experiment is to observe chemical changes in common consumer products to determine if the chemicals are basic, acidic, or remain neutral when mixed with other chemicals.

The color of the solution was turning slightly into yellow and the color of the iron strip into white.

The two most obvious formation of the precipitate were the combinations with the MgSO4. The MgSO4 and NH3 solution became very opaque and the MgSO4 and Na2CO3 turned from liquid to a full solid white substance. The Na2CO3 and CH3COOH did not have as strong of a reaction, however, the precipitates were able to be visualized with in the clear

The Vitamin C turned to a red/orange color with no physical/chemical reaction. For the salt the solution turned to an orange color with no physical/chemical reaction. With the Alka-Seltzer, the solution turned to a brown color with no reaction as well. Last but not least, the Baking soda turned to an orange/brown color with no reaction.

In this experiment an elemental copper was cycled a series of five reactions where it ended with pure elemental copper as well, but at different stages of the cycle the copper was in different forms. In the first reaction, elemental copper was reacted with concentrated nitric acid where copper changed the form from solid to aqueous. Second reaction then converted the aqueous Cu2+ into the solid copper II hydroxide (Cu(OH)2) through reaction with sodium hydroxide. The third reaction takes advantage of the fact that Cu(OH)2 is thermally unstable. When heated, Cu(OH)2 decomposes (breaks down into smaller substances) into copper II oxide and water. When the solid CuO is reacted with sulfuric acid, the copper is returned to solution as an ion (Cu2+). The cycle of reactions is completed with the

When the red Co(NO3)2*6H2O crystal was added to the white NH4 crystal, and water was added to dissolve, the solution turned blue in color. As the solution was nixed, the color changed to that of a blue-purple and a blue precipitate formed. When the 6 M NH3 began to be added, the color shifted to dark purple color after 15 mL of ammonia and the amount of the precipitate was less. After 20 mL of ammonia, the solution became a red brown with very little of the blue precipitate. After 30 mL of ammonia, the solution was similar in color to an iodine solution, a dark brown-red, almost black in color. At this point there was no visible precipitate on the surface of the solution. After 40 mL of the ammonia had been added, the solution was the same iodine like color as before. When closely examined, there was a black precipitate that had settled on the bottom of the beaker. At this point, hydrogen peroxide, 3% H2O2, was added to solution. After 4 mL of the H2O2 was added, the solution was the same color and the precipitate had not changes. After 8 mL of the H2O2, there was not noticeable change. After 12 mL of the H2O2, the solution was slightly redder in color but the precipitate had not changed. After 15 mL of H2O2, the solution was the same color and no changes had occurred to the precipitate. At 17 mL, the solution began to effervesce slightly, though there

When the zinc was dropped in the hydrochloric acid, the substance began bubbling vigorously, forming a precipitate. Eventually, the zinc dissolved completely. After the lit wooden splint broke the surface of the test tube, there was a loud popping noise. The gas that was released was hydrogen from the acid and the popping noise was a result of the Hydrogen being burned up by the fire creating a small explosion. Two chemical changes occurred in this test: one with the formation of a precipitate (a textbook sign of a chemical change), and the other when the explosion

Fill a test tube about 1/3 full with cold tap water for use in step 34.

The purpose of this experiment is to distinguish the relationships between reactants and products, in addition to expanding on concepts such as single displacement reactions, mole ratio values, moles to mass, theoretical yields, limiting reactants, excess, stoichiometric relationships and percentage errors.

If you see a deep blue color add more zinc powder until there is no change in color of the solution in the test tube.

We mixed Mg and CuCl2 together and the magnesium began to change due to the reaction. We mixed Zn and CuCl2 together and saw that the Zinc has began to change it’s color due to its reaction. We mixed Mg, Fe and Zn with Fe(NO3)3 and saw that they all had a reaction and began to change. We later noticed that Copper hadn’t reacted with any of the substances because it didn’t change it’s color or form.

This experiment explores the properties of physical changes by using several mixtures to help urge the change. A physical change affects the form of a chemical substance, not its composition. No chemical changes will be taking place during this experiment because no new substance will be formed. There will however be 2 phase changes occurring during this experiment; the solidification of the mixture to ice cream in the quart zip lock bag and the endothermic reaction taking place in the gallon bag. Solidification is when the substance changes from a liquid state to a solid state by Generally, this occurs when the temperature of a liquid is lowered below its freezing point, hence the mixture of the milk, ice cream salt, and vanilla later developing

The solution had vigourous effervescence, and was white for the duration of the reaction before turning clear again.

After swirling the resulting solution, it kept cycling through appearing as yellow and clear. However, there was constantly a small patch of blue residue caused by some undissolved starch powder. There was some gas formation during this process. After 5 minutes, we