Name: Teacher s Name: Class: Block: Date: Partners: Limiting Reactants Lab Purpose: Through experimentation, determine the limiting reactant and the percent yield in a chemical reaction that generates a gas. Prelab Questions: 1. Calculate the molar mass sodium bicarbonate: 2. Calculate the molar mass carbon dioxide: 3. Calculate the number moles HCl in 12 ml 1.0 M HCl: Conversion equation: (1.0 M HCl means 1.0 moles HCl per liter) 1.0 moles HCl 1 liter ml HCl 1 liter HCl 1000 ml 4. Predict which will inflate the most and explain your reasoning. 5. Write the balanced equation for the reaction: hydrochloric acid reacts with sodium bicarbonate to produce carbon dioxide and sodium chloride and water. Materials: 1.0 M hydrochloric acid (HCl), sodium bicarbonate (NaHCO3), s, test tubes, graduated cylinder, test tube rack, funnel, gram balance, calculator, pencil, Sharpie marker Safety: Goggles and lab apron must be worn. Hold s on the test tubes tightly while the reaction takes place.
Procedure: You will be working in teams four each team member will have specific jobs to do all members will do the calculations. Decide who will be letters A, B, C, & D and record partner names: A. B. C. D. 1. Follow the directions below: Student A: Weigh the following amounts sodium bicarbonate, commonly known as baking soda. 0.18 grams, 0.35 grams, 0.52 grams, 0.70 grams, 1.00 grams, and 1.70 grams Student B: Label the s 1, 2, 3,... Weigh the empty s. Put the different masses baking soda into the numbered s using a small plastic funnel. Make sure the baking soda goes to the bottom the. Students A & B: Work together and reweigh the s after adding the baking soda. Student C: Using the graduated cylinder and HCl provided, accurately measure and transfer 12.0 ml HCl into each the test tubes. Student D: Attach the filled s to the mouth the test tubes. Make sure that the contents the and test tube are not mixed. 3. Each group member lifts a so all the solid goes into the liquid. 4. Observe the reaction and record observations in data table. 5. When reaction is complete, carefully remove without allowing gas to escape, tie f, and weigh. 6. Clean up.
Data: Limiting Reactants Lab 1 Measure: Weigh: Weigh: Weigh: Calculate: Weigh: Calculate: Volume HCl in test tube (ml) Color in dish & mass gasfilled mass CO 2 gas collected Observations during reaction 2 3 4 5 6 Data Analysis: 1) Does each inflate to some degree? Why? a) Make a graph the mass CO2 vs. number. Make number the independent variable. b) Use your observations and the graph to compare the degree to which each inflated. 2) What does the degree inflation the tell you about the reactions in the test tube? 3) What is the pattern inflation in the test tubes 1-3? In test tubes 4-6? 4) Noting that the mass baking soda increases, what effect does this have on the reactions in test tubes 1-3? In test tubes 4-6?
Calculations: Limiting Reactants Lab Calculate the expected mass CO2 produced from each reactant. Circle the limiting reactant in each experiment. 1 Starting Amount (in moles) HCl Starting Amount (in grams) NaHCO3 Expected mass (in grams) CO2 Based on the limiting reagent Percent Yield CO2 2 3 4 5 6 Perform Limiting Reactant Calculations Below: Choose one your # s above and do the following calculations: Expected mass CO2 produced from the HCl: Expected mass CO2 produced from the NaHCO3: Limiting Reagent for this # : % Yield CO2 ***5 points Extra Credit: Perform Limiting Reactant and Percent Yield Calculations for all the s. ***
Conclusions, Error Analysis, Comments: Limiting Reactants Lab Conclusions (6 points): How did this lab meet its purpose? Use the following academic vocabulary in your conclusion paragraph: limiting reactant, excess reactant, percent yield, grams, moles, and mole ratio. Write a 5-6 sentence conclusion paragraph. Infer or guess what you think happened to answer the purpose the lab. For maximum points, discuss the theory we are studying in class and how it applies to the lab. Show me all you know about the topic. Error Analysis (2 points): What caused the % yield to be different than exactly 100% in this lab? Comments (2 points): Did you like the lab? Why or why not? What would you do differently next time? Would you do a follow-up lab? This is your chance to make comments. Write at least 2 sentences.