Q 1 Experiment 08 - Chemical Reactions and Chemical Equations • Points 25 • Submitting a file upload Today we start Experiment 08. You can find a .pdf copy of the Experiment in the Laboratory Manual Module. This lab is considered part "wet lab" and part "dry lab", as we use chemicals and laboratory equipment to collect the Observations in Part A, but Part B and the Postlab Questions are simply worksheets. The lab is designed to let you observe evidence of chemical reactions, and give you practice in writing and balancing chemical equations. For Part A, we cannot meet in the lab room to perform and observe the reactions directly. This is a shame, as the reactions are fun and the observations are important. For real-life examples of these reactions, I'm embedding videos from YouTube that show the reactions occur. Record your observations in the Data Table for Part A after watching the demonstration videos. Reaction #1: Reaction #2: Reaction #3: One product of this reaction is carbon dioxide gas, which fills the test tube, displacing any oxygen gas inside the tube. Combustion requires oxygen, so when the burning wood is placed inside the tube, the flame is extinguished, as no oxygen gas is present. Reaction #4: Reaction #5: Reaction #6: Reaction #7: Note - this video is using Copper (II) chloride instead of Copper (II) nitrate, but the cloudy blue solid that forms as the visible product (Copper (II) phosphate) would be the same. Reaction #8: Note - this video is using Aluminum chloride instead of Aluminum nitrate, but the cloudy white solid that forms as the visible product (Aluminum phosphate) would be the same. Reaction #9: Reactions #10 and 11: This video isn't exactly the reactions we're performing, but it does show the color change that we expect to see. Both of these acid/base neutralization reactions use an indicator compound (this one is called phenolphthalein) that changes color when the pH of the solution changes. When we add a base to an acid, the pH rises and the color of the phenolphthalein turns from clear to bright pink. Reaction #12: Once you've completed the Observations for Part A, you can start Part B, which has you write and balance a chemical equation for the each of the 12 reactions in Part A. They're mostly standard reactions, with one exception: Reaction #2 starts with a unique type of crystalline solid called a hydrate. Hydrates are ionic compounds that have water molecules as part of their overall structure. The water isn't permanently bonded to the salt, they're just part of the same crystal structure. They're unique in that the water molecules in a hydrate are "solid" even at room temperature. We write the chemical formula of a hydrate with a dot separating the salt from the water: CuSO4 5 H2O The ratio of salt to water here is exactly 1:5 (thus the name pentahydrate - 5 water). When the hydrate is heated, the water and the salt separate, and are written as separate products. CuSO4 5 H2O ---> CuSO4 + 5 H2O You should be able to complete Part A, Part B, and Parts 1 and 2 of the Postlab from the material covered in today's lecture. You can continue to Parts 3 and 4 of the Postlab after our next lecture, which covers the different types of reactions, and how to predict the products of a chemical reaction. Fill out the lab pages and save your work as a .pdf document, and submit your work using the Submit Assignment button at the top of the page.