OCTOBER 29 & MS. BOON CHEMISTRY Stoichiometry 6

Objective: I can analyze laboratory data, identify sources of error, and write a well-reasoned lab report. Agenda: Catalyst Lab Day 3 Exit Slip Review Let’s write a lab report! Catalyst: Today is the third and last day of our copper and silver nitrate stoichiometry lab. If you could do this lab again, or another one like it, what would you add to the lab to make it more interesting, informative, or fun?

Warm Up – Lab Day 3 Before we measure the mass of our silver. Let’s watch a video. Focus Question: Describe what you see using scientific vocabulary. (chemical reaction, single- displacement, reactants, products)

Agenda Catalyst Lab Day 3 – Data Collection & Begin Calculations Exit Slip Review Let’s write a lab report!

Lab Day 3: Data Collection (7 minutes) The last step in the lab procedure is to measure the mass of the filter paper with the silver. Each lab group must assign one person to pick up their materials and another person to read the triple beam balance. Record your results in the Day 2/3 data table Begin the Day 3 Calculations while we wait for all groups to finish.

Exit Slip 10.25&26 – Standard 3a, 3d, 3e, 3f Balance the chemical reaction equation. ___Li + __O 2  ___Li 2 O 1. What is the molar mass of Li? 1. 7 g/mol 2. What is the molar mass of Li 2 O? = 30 g/mol 3. What is the molar mass of O 2 ? = 32 g/mol 4. What is the mole ratio of Li 2 O to Li in the balanced equation? 1. 2 mol Li 2 O 2. 4 mol Li 5. What is the mole ratio of Li 2 O to O 2 in the balanced equation? 1. 2 mol Li 2 O 2. 1 mol O 2 6. How many grams Li 2 O will be produced from 56 g Li? 7. How many grams Li 2 O will be produced from 32 g O 2 ? 8. Identify the limiting reactant and the theoretical (calculated) yield of silver Li 2 O in grams, when 56 g Li reacts with 32 g O If the actual yield is 30 g Li 2 O, what is the percent yield? Balance the chemical reaction equation. ___Li + __O 2  ___Li 2 O 1. What is the molar mass of Li? 1. 7 g/mol 2. What is the molar mass of Li 2 O? = 30 g/mol 3. What is the molar mass of O 2 ? = 32 g/mol 4. What is the mole ratio of Li 2 O to Li in the balanced equation? 1. 2 mol Li 2 O 2. 4 mol Li 5. What is the mole ratio of Li 2 O to O 2 in the balanced equation? 1. 2 mol Li 2 O 2. 1 mol O 2 6. How many grams Li 2 O will be produced from 56 g Li? 7. How many grams Li 2 O will be produced from 32 g O 2 ? 8. Identify the limiting reactant and the theoretical (calculated) yield of silver Li 2 O in grams, when 56 g Li reacts with 32 g O If the actual yield is 30 g Li 2 O, what is the percent yield?

Exit Slip 10.25&26 – 3a, 3d, 3e, 3f Review 6. How many grams Li 2 O will be produced from 56 g Li? 7. How many grams Li 2 O will be produced from 32 g O 2 ? 8. Identify the limiting reactant and the theoretical (calculated) yield of silver Li 2 O in grams, when 56 g Li reacts with 32 g O If the actual yield is 30 g Li 2 O, what is the percent yield?

Let’s Write a Lab Report Lab Report Criteria: Overview Length: 4 paragraphs + attach all data, calculations, and observations. Time: We will work on this today in class. Due today. Academic standards assessed:  IE 1b – identifying sources of error  W 1.3 – writing a logical and reasoned explanation Format Requirements: Title Lab Report: Stoichiometry Lab - Copper and Silver Nitrate Reaction Introduction Paragraph explains the concept behind the lab. Procedure Paragraph explains the lab procedure. Data Analysis Paragraph explains the data and calculations. Conclusion Paragraph analyzes sources of error and presents next steps.

Let’s Write a Lab Report Lab Report Criteria: Overview Title Lab Report: Stoichiometry Lab - Copper and Silver Nitrate Reaction Introduction Paragraph explains the concept behind the lab. The first sentence should state the purpose of the lab. Define terms (limiting reactant, excess reactant, theoretical yield; actual yield; percent yield) Write a descriptive explanation of the single replacement reaction between copper and silver nitrate.

Let’s Write a Lab Report Lab Report Criteria: Overview Procedure Paragraph explains the lab procedure. Write at least 5 sentences explaining the specific steps of the lab. (How did you set up the experiment? What did you measure? What did you do on each day? Did you do anything different than the written procedure?)

Let’s Write a Lab Report Lab Report Criteria: Overview Data Analysis Paragraph explains the data and calculations What was your theoretical yield and what measurement did you use to calculate it? What was your actual yield and what measurements did you use to calculate it? What was your percent yield and what measurements did you use to calculate it? Attach all calculations.

Let’s Write a Lab Report Lab Report Criteria: Overview Conclusion Paragraph analyzes sources of error and presents next steps. Provide at least three sources of error that may have affected your measurements. Why was your actual yield different than your theoretical yield? If you were to do a lab like this again, what next steps would you add?