The first part of this experiment involved mixing the compounds, provided by Hands-On Lab, in a 24-well plate. Aqueous solutions of ionic compounds were mixed in eight separate wells. A few drops Of each solution were mixed in a well and any reaction was immediately observed and recorded. A table was made noting the ionic compounds being mixed, along with a brief description of any chemical reactions that were observed.
The second part of the experiment was to observe solid elements being heated in a test tube, as well as, being ignited in a combustion reaction. Metal elements and compounds provided by Hands-on Lab were first heated in a test tube over an open flame. Next, each solid substance was placed over the open flame using either tweezers or a metal spatula. A table was made noting the initial observation, including when the substance was being heated, and when the solid element or compound was ignited by a direct flame.
Mixing Aqueous Solutions of Ionic Compounds Ionic Compounds Mixed Description of Reaction Chemical Reaction HCI’ + Enhance Colorless, effervescing Yes (1) Nasal + KIWI No reaction NO (2) Nasal + KIWI + Starch No KIWI + BP(NON)2 Bright yellow, cloudy, precipitate Noah + C20H1404 purple, pink, opaque HCI + C20H1404 Noah + Again Clear pink, brown precipitate Milky white, cloudy precipitate Again + NH + sunlight
Purple brown dry paper towel NH + Again Cloudy, light blue, precipitate Heating and Igniting Metallic Substances Solid Substance Description of Reaction Observed Chemical Initial During Heating During Burning MGM Silver color, small metal shards Sparked, glowed white, white residue Sparked, bright flame, white residue Zen Silver color, random shape, metal bits Melted, turned blue green color Melted, cooled back to solid cue Light green, fine powder Black, charred powder Flame turned green, minimal residue Grainy, blue crystals Melted, bubbled, produce yellow orange smoke Spark, green flame, minimal residue
Calculation and Errors: Calculations were not required for this experiment. Observational errors could have been reduced by utilizing a camera to record the reactions. Recording the reactions would have allowed the opportunity to review and record increased data throughout the reaction. Also, the reactions should have been repeated, in order to identify any anomalies in the observational data. Discussion and Conclusion: The variance of reactions that I was able to observe was intriguing.
Only three of the tests failed to have any reaction at all, throughout the experiment. It was interesting that sunlight would act as a totally creating a chemical reaction after being placed in direct sunlight for thirty minutes. It was also very interesting that reactions took place with metal, while being heated in a test tube over an open flame. The combustion reactions should have been repeated, however, residential housing and lack of proper ventilation eliminated the possibility for increased or repeated combustion tests.
Answers to Questions: Part 1 E. Yellow-brown color may indicate the presence of nitrates in the brand of cookies. G. A physical change. The chemical composition of the pie remains unchanged. K. A. Chemical change b. Physical change c. Physical d. Chemical e. Chemical change f. Physical change g. Physical h. Chemical part 2 A. Sodium bicarbonate effervesced, produced bubbles of gas when mixed with Hydrochloric Acid (HCI). C. Well AAA, HCI + Enhance, was colorless with effervescing gas bubbles. D.
When Phenolphthalein was mixed with HCI, the solution remained colorless. Pink color would indicate the solution was a base, not vinegar (an acid). F. When lead nitrate and potassium iodine are mixed, a yellow precipitate can be observed from the reaction. H. A physical reaction. The CA bubbles being released from the can do not change the Heimlich composition of the beverage’s solution. L. Photon rays caused a chemical change. The photons caused the solution to turn from colorless to purplish-brown.