Decomposition of Sodium Bicarbonate Stoichiometry Lab, Lab Reports of Chemistry

Download Decomposition of Sodium Bicarbonate Stoichiometry Lab and more Lab Reports Chemistry in PDF only on Docsity! Decomposition of Sodium Bicarbonate Stoichiometry Lab OBJECTIVES The purpose of this lab is to: -Perform a decomposition reaction and measure the mass of the product(s) formed -Using stoichiometry to determine which thermal decomposition reaction occurred during the experiment -Calculate the percent yield and error for your experiment. BACKGROUND The word stoichiometry originates from the Greek words stoicheion; meaning element and metron; meaning measure. We use stoichiometry to describe the relationship between the relative quantities of substances taking part in a reaction or forming a compound, and are typically a ratio of whole integers. In this lab, you will use stoichiometry to probe the decomposition of sodium bicarbonate. Sodium bicarbonate may be more familiar to you as baking soda. Baking soda is very commonly listed as an ingredient in recipes for baked goods, pancakes and waffles. As the food item is being cooked or baked, the baking soda undergoes decomposition, releasing gas and causing the food item to “rise” and have a “light” texture. There are three theoretically possible chemical reactions that could occur during the thermal decomposition of baking soda. 1) sodium bicarbonate (s) → sodium hydroxide (s) + carbon dioxide (g) 2) sodium bicarbonate (s) → sodium oxide (s) + carbon dioxide (g) + water (g) 3) sodium bicarbonate (s)→ sodium carbonate (s) + carbon dioxide (g) + water (g) By comparing the theoretical yields of the possible solid products with the actual experimental yield of the product, you will be able to determine which of the above decomposition reactions occurred. REQUIRED SUPPLIES Sodium bicarbonate Bunsen Burner Crucible Ceramic triangle Iron ring clamp Balance Crucible tongs PROCEDURE 1) Place a clean crucible on a ceramic triangle that is sitting on a iron ring clamp attached to a ring stand. 2) Using a Bunsen burner heat the crucible for 5 minutes on a low temperature and then allow to cool for approximately 10 minutes. 3) Bring your fingernail close to the crucible to determine if the crucible has cooled. Please note, that once the crucible has been heated, you cannot touch the crucible for the duration of the experiment with your fingers. The crucible is a porous material and will absorb the oils from your fingers skewing your experimental results. 4) Using crucible tongs, carry the crucible to the balance to get the mass of the cool crucible. 5) Add between 4-5g of sodium bicarbonate to the crucible and record the exact mass of the sodium bicarbonate being used. 6) Heat the crucible and sodium bicarbonate on a low flame for 2 minutes and then on a medium-high flame for 8-10 minutes. 7) After allowing the crucible to cool, take the mass of the crucible and product (s). 8) Repeat the heating of the crucible on a low flame followed by the medium-high flame again. 9) Once the crucible has again cooled take the mass of the crucible and product again. If the mass difference between the two heating cycles is greater than 0.1g, repeat the heating process again to ensure that the thermal decomposition has been completed and all of the gas products have been driven off. 10) Once the mass of product and crucible remain constant, discard the solid product as directed by your instructor, wash and dry the crucible and return all equipment to their initial location.