Ms. Whitty, Science 10
Fiona Adams, November 1st, 2012
Chemical reactions are a part of our daily lives, from rusting metal to making bread to leaves changing colour in the fall. A chemical reaction is the process that occurs when two or more substances combine to produce a chemical change. When a chemical reaction takes place, the change is indicated by one or more qualitative properties. The colour or odor could change, gas could be produced, a precipitate – a solid substance in a solution - could be formed, or energy could be absorbed or released. The substances initially involved in a chemical reaction are called reactants. When chemical reactions occur, the end result is called a product. Products usually have different properties than reactants; bonds between atoms will be changed during the reaction, switch the atoms’ arrangement in different compounds. A compound is a chemical substance that consists of two or more different chemically bonded elements. In this experiment, several different compounds are being worked with – potassium iodide, lead (II) nitrate, acetic acid and sodium bicarbonate. The purpose of this experiment is to determine whether or not a reaction has taken place using qualitative and quantitative analysis.
Part 1 -
Qualitative observations of both potassium iodide and lead (II) nitrate were recorded in a table. Then, the equipment and chemicals needed were gathered – potassium iodide and lead (II) nitrate, a graduated cylinder, Erlenmeyer flask, small test tube, rubber stopper, and small scale. Using the graduated cylinder, 10 mL of potassium iodide solution was measured and poured into the Erlenmeyer flask. Next, the lead (II) nitrate solution was poured into the small test tube until it was approximately half full. The test tube was placed inside the Erlenmeyer flask, and sealed with a rubber stopper – the solutions were not mixed. The mass of flask, stopper and
References: University of Washington. Chemical Reactions – an Introduction. http://depts.washington.edu/chemcrs/bulkdisk/chem110A_aut01/notes_Week_5.pdf (accessed Oct. 30, 2012). Science Daily. Science Reference – Chemical Compound. http://www.sciencedaily.com/articles/c/chemical_compound.htm (accessed Oct. 30, 2012). American University. Oil Production and Environmental Damage. http://www1.american.edu/ted/projects/tedcross/xoilpr15.htm (accessed Oct. 30, 2012). Chem Professor. Reactants and Products. http://www.chemprofessor.com/outline7b.htm (accessed Oct. 30, 2012).