Chemical Reactions Portland Community College Staff Version 42-0145-00-01 Lab Report Assistant This document is not meant to be a substitute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment’s questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate students’ writing of lab reports by providing this information in an editable file which can be sent to an instructor. Observations Data Table 1: Reactions on Al foil Rxn# Reactant What reactants look like Initial Appearance of Foil Appearance of Foil after 5 Min Appearance of Foil after 1 Hr 1. AgNO3 2. Na2CO3 3. CuSO4 4. CaCl2 5. Pb(NO3)2 Data Table 2: Observations of reactions mixtures: (c/c = clear and colorless liquid) Rxn# Reactants Initial Observation of Reactants Observation of Reactants After being Mixed Together a NaHCO3 + HCl b HCl + blue dye c Blue dye + NaOCl Then HCl d NaOCl + KI Then starch e KI + Pb(NO3)2 f Pb(NO3)2 + CaCl2 g CaCl2 + NaHSO4 h NaHSO4 + Na2CO3 i Na2CO3 + phen j Phen + NaOH k NaOH + AgNO3 l* AgNO3 + NH3 **Paper: m* NH3 + CuSO4 n CuSO4 + NaHCO3 Questions A. The use of the initial vinegar and salt solution was to ensure the Al surface was clean and free from oxides. This left elemental aluminum free to react. 1. Which ions reacted with Al(s)? 2. Which ones do not react with Al(s)? 3. List each reaction that occurred with the solid aluminum. B. If left to stand long enough in oxygen, the solid metal residues observed and recorded in Data Table 1 will start to darken. 1. What is forming? 2. What type of reaction is this? 3. List each reaction of solid residue with air. C. Review the results in Data Table 2. The first reaction produces CO2, a gas. 1. Name several consumer products containing CO2? 2. Which other reaction produced a gas? List the reaction number. 3. What kind of gas was produced? D. Which reactions produced a color change without the formation of a solid? E. Which reactions produced a solid? F. Review Data Table 2, identify 7 double-displacement reactions, and write the reactions for each of these mixtures. (Hint: e, f, g, k, l, m, n) Which of these reactions is also classified as an acid-base neutralization reaction? List the reaction number. G. Some silver compounds are photo reactive. What is the formula for the photo reactive silver compound produced? List the formula and explain why the compound is photo reactive. Experimental Insert Rxn# Reactants Observation when the reactants are mixed together Rxn# Reactants Observation when the reactants are mixed together a NaHCO3 + HCl X h NaHSO4 + Na2CO3 X b HCl + blue dye X i Na2CO3 + phen X c Blue dye + NaOCl Then HCl X j Phen + NaOH X d NaOCl + KI Then starch X k NaOH + AgNO3 X e KI + Pb(NO3)2 X l* AgNO3 + NH3 X f Pb(NO3)2 + CaCl2 X m* NH3 + CuSO4 X g CaCl2 + NaHSO4 X n CuSO4 + NaHCO3 X