c: 13 dec. 2010 objective: swbat peer edit a classmate’s lab report. do now: what was the most...

C: 13 Dec. 2010

Objective: SWBAT peer edit a classmate’s lab report.

Do now: What was the most difficult lab report section to write? Why?

Agenda

I. Do nowII. Review percent compositionIII. Peer Editing How-toIV. Peer Editing Work TimeV. Get back your own lab reportHomework: Hand in any missing work

and/or schedule an appointment to take a missed test or quiz or re-quiz!!

Final lab report due next Monday!

Final draft of lab report

Do you want more advice on improving your lab report?

Come for extra help today or tomorrow at 3:30 in 203!

Percent Composition

Percent of water in CuSO4∙5H2O

Peer editing

1. Reach each section of the lab report and circle the box on the rubric (p. 1) that best describes the qualities of that section.Do not give points!

2. While you read, fill in the chart on page 2 (what works well, suggestions for improvement)

3. Give one specific praise or suggestion for each box!!

Then…

Give a score 1, 2, or 3 for each statement in part 3

Give the top 3 things for the person to focus on when revising. If they only fixed three things,

what should they be?!

For example

For the Data and Results partWhat works well: Your descriptions

of your qualitative data are complete and thoughtful!

Suggestions for Improvement: You should explain what you are doing for each step of your calculations.

Three Things…Example

1. Write your procedure as paragraphs, not a list.

2. Include a calculation for actual percent composition for water in the hydrate.

3. Include one more error and how it affected your results.

For the rest of the period….

Work quietly on your own. If you’re not sure how to score a

section, or what to write, you may quietly ask your partner or me.

Return the lab report and two page handout to me.

Homework

Hand in any missing work and/or schedule an appointment to take a missed test or quiz or re-quiz!!

Final lab report due next Monday!

C: 14 Dec. 2010

Objective: SWBAT calculate mass relationships in chemical reactions.

Do now:

2KNO3(s) 2KNO2(s) + O2(g)

a. How many moles of KNO2 are produced by the reaction of 2 moles of KNO3?

b. How many moles of oxygen gas are produced by the reaction of 0.50 moles of KNO3?

Agenda

I. Do nowII. Review mole relationshipsIII. Mass relationships!IV. Hand back lab reportsHomework: Week 15 Homework #1 (PAGE 1-2!)Lab report final draft Monday.

Work along on your worksheet!

Mass Relationships in Chemical Reactions

SWBAT calculate mass relationships in chemical reactions.

Reviewing Mole Relationships

2KNO3(s) 2KNO2(s) + O2(g)

1. How many moles of O2 are produced when 2 moles of KNO2 are produced?

2. How many moles of KNO3 are required to produce 4 moles of KNO2?

3. How many moles of KNO3 are required to produce 5 moles of O2?

4. How many moles of O2 are produced by the reaction of 13.5 moles of KNO3?SWBAT calculate mass relationships in chemical

reactions.

What if, instead of moles, the problem gives you grams of a reactant or product and asks you to calculate grams of another reactant or product?!


Reaction Stoichiometry

Calculating:• The number of moles and grams of

reactants that combine• The number of moles and grams of

products producedYou already know every part of reaction

stoichiometry.The trick is putting these skills

together into one process.


Part I

First, review moles to moles stoichiometry

4Al(s) + 3O2(g) → 2Al2O3(s)

PART I: Use the equation above to solve the following problems:

STEP 1: Write the given value, with a unit, over oneSTEP 2: Write a blank conversion factorSTEP 3: Put your given unit and substance on the

bottom of your conversion factor and the units you want to find on the top of your conversion factor

STEP 4: fill in the numbers in your conversion factor using the equation

STEP 5: Multiply what’s on top, divide by what’s on bottom. Write your final answer.

PART II: Now let’s say we wanted to know how many grams would be produced/needed rather than how many moles? What could we do to find this?

To find grams from moles___________________1. Use your answer from STEP 5 as your new given,

put it over 12. Write a blank conversion factor3. Put your given unit and substance on the bottom

of your conversion factor and the units you want to find (grams) on the top of your conversion factor

4. Fill in the numbers using the molar mass of that substance

5. Multiply what’s on top, divide by what’s on bottom. Write your final answer.

PART III:Now you have converted:

MOLES of A MOLES of B MASS of B Using: ______________ Using: ______________But in the lab, we usually need to measure our

substances in grams on both ends, so we need to be able to answer questions like:

Example 1: How many grams of aluminum are needed to produce 9 grams of aluminum oxide?

How could we solve this problem?MASS of A MOLES of A MOLES of B MASS

of BUsing: _______Using: _________ Using: _________

Just like when doing 2 step conversions in the past, to solve these multi-step problems:

1. Make a _______________________2. When in doubt on where to start,

convert to _______________

A: 14 Dec. 2010

Take Out Homework: Week 15 Objective: SWBAT calculate mass

relationships in chemical equations. Do now: 4Al(s) + 3O2(g) → 2Al2O3(s)

a. How many moles of aluminum oxide will be produced by the reaction of 25 moles of aluminum?

b. How many grams of aluminum oxide is that?

Agenda

I. Do nowII. Mass to mass conversions examplesIII. Practice ProblemsIV. Copper Cycle Pre-LabV. Hand back lab reportsHomework: Week 15 Homework finish #1,

#2 (PAGES 3-4): Thurs.Lab report final draft due MondayRead Lab Handout Procedure, do pre-lab

questions and become an expert

4Al(s) + 3O2(g) → 2Al2O3(s)

Example 1: How many grams of aluminum are needed to produce 9 grams of aluminum oxide?

SWBAT calculate mass relationships in chemical equations.

4Al(s) + 3O2(g) → 2Al2O3(s)

Example 2: How many grams of aluminum oxide can be produced from 13 grams of aluminum?


4Al(s) + 3O2(g) → 2Al2O3(s)

Example 3: How many grams of oxygen gas are needed to react with 11 grams of aluminum?


C: Homework

Week 15 Homework #1 (PAGE 1-2) Lab report final draft: Mon. If you didn’t get your lab report

back, please come talk to me!Come to extra help for…extra help!


A: Homework

Week 15 Homework #1 (finish) #2 (PAGE 3-4!!): Thurs

Lab report final draft: Mon. Read Lab Handout, do pre-lab

questions, and become the expert on your section: due tomorrow

Come to extra help for…extra help!


C: 15 Dec. 2010

Take Out Homework: Week 15 Homework p. 1-2

Objective: SWBAT calculate mass relationships in chemical reactions.

Do now: Write and balance the equation:

Hydrogen gas reacts with chlorine gas to produce a solution of hydrochloric acid.

Agenda

I. Do nowII. Homework solutionsIII. A few more mass to mass calculation

problemsIV. Pre-lab discussion of safetyV. Read procedure and become an expertHomework: Week 15 #2 (PAGES 3-4): Mon.Do pre-lab, including procedure questions:

Fri.Final lab report: Mon.

H2(g) + Cl2(g) 2HCl(g)

1. How many grams of hydrochloric acid are produced when 3.50 grams of hydrogen is reacted with excess chlorine gas?

excess: more than enough2. How many grams of hydrogen gas are

required to produce 5.00 grams of hydrochloric acid?

3. How many grams of chlorine gas reacts exactly with 4.9 grams of hydrogen gas?SWBAT calculate mass relationships in chemical reactions.

4Fe(s) + 3O2(g) 2Fe2O3(s)

1. How many grams of iron (III) oxide are produced by the reaction of 1.00 grams of iron in excess oxygen?

2. How many grams of oxygen are required to react exactly with 5.00 grams of iron?

3. How many grams of oxygen are required to produce 3.50 grams of iron(III) oxide?

4. How many grams of iron (III) oxide are produced by the reaction of 0.50 grams of oxygen with excess iron?SWBAT calculate mass relationships in chemical reactions.

COPPER CYCLE LAB

Cu L8R!

Safety

This lab uses HIGH concentrations of chemicals Chemicals could burn skin, clothing,

and eyes MUST wear goggles at all times in lab

May take 1minute goggle breaks in the hallway as needed (2 at a time)

If you are not wearing your goggles in the lab, I will ask you to go to the office until you can behave safely.

Chemical burns

Safety What does “behaving safely” look like? Examples:

Stay at lab station, don’t wander the room Be careful with glassware and chemicals Never squirt anyone or anything with any

chemical (INCLUDING WATER) Notify Ms. Boiteau of any spills/breakage

right away – clean thoroughly MUST behave carefully and safely

If you are not behaving safely, I will ask you to go to the office until you can behave safely.

You are the experts!

Each group member will be an expert on one section of the procedure

This person is responsible for managing that part of the procedure for the group Understanding what is going on Being the primary ‘doer’ during

that section – measuring chemicals, etc.

Your group is counting on you!

For the rest of the period…

1. Do the pre-lab questions on the front page.

2. Read the procedure.3. For the section for which you are

the expert, complete the questions after those procedure steps.

Due tomorrow!!

Homework

Week 15 #2 (PAGES 3-4): Mon. Do pre-lab, including procedure

questions: Fri. Final lab report: Mon.

c: 13 dec. 2010 objective: swbat peer edit a classmate’s lab report. do now: what was the most...

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