Observations of Chemical Changes Essay

Objective: This experiment is meant to show how certain chemicals react with each other and can be identified by these reactions Procedure: Several different chemical mixtures were poured into the well plate and observed. These included sodium bicarbonate and hydrochloric acid, bromothymol blue and hydrochloric acid, ammonia and bromothymol blue, hydrochloric acid and blue dye, blue dye and sodium hypochlorite, potassium iodide and lead nitrate, sodium hydroxide and phenolphthalein, hydrochloric acid and phenolphthalein, sodium hydroxide and sliver nitrate, ammonia and silver nitrate, and ammonia and copper (II) sulfate. Some mixtures were also placed in the light or mixed with additional hydrochloric acid or dye. Observation Table: Questions: a.) Silver nitrate could easily be used to test for sodium bicarbonate since it causes the chemical to turn brown. b.) Windex- turns orange with BTB and red with phenolphthalein- base Dish soap- turns yellow with BTB and red with phenolphthalein- base Bleach- turns orange with BTB and purple with phenolphthalein- base Scrubbing Bubbles- turns blue with BTB and gray with phenolphthalein- acid c.) The solution contains no vinegar or a very small amount of vinegar because a pink color indicates a basic solution, and vinegar is and acid. d.) The yellow flavor is more acidic and the blue flavor is more basic. e.) Combining the mixture with potassium iodide could easily test for the presence of lead. If the mixture contained lead, then the potassium iodide would cause the mixture to turn yellow and thick like a solid. Conclusion: Many chemicals will produce obvious physical changes when mixed with other chemicals. These mixtures usually result in a change in color or consistency, which can distinguish them from other chemicals. While certain chemicals may react the same way with on mixture, testing a chemical with multiple mixtures will most likely allow the chemical to be identified.