AnnouncementsThere aren’t usually this many announcements, I promise -- just a lot in

the beginning of the year Have your calculator out today.Bring a timing device next class for the How Observant Activity.Bring Unit 1 Packet next class (Sharepoint). Also review Unit 1 Other

Stuff and print the things that look like you should print them.You do NOT have to print lectures. You may. You may also pull them on

on an electronic device during lecture, whatever you think will help you learn.

We will go over the expectations for lab reports during the last 20 minutes of class today.

Warmups are not graded. If I notice that you repeatedly take 5 minutes to start Warmups, pretend to do them, don’t do them at all, etc, we have a problem! The point is to DO your warmup, not to write the questions down.

Element Symbol Quiz : 2 blocks from todayFor elements beginning with the same letter, like carbon and calcium…..make a list, or make flash cards

Most symbols are the first letter or first two letters of the name, but watch out! For elements like silver (Ag), make a flash card, because Si = silicon!

Second letter is ALWAYS lowercase

Two practice quizzes have been uploaded to Sharepoint. They are in the same format as the quiz.

Warmup (7 minutes)

The mass of an SISS sample is 4.56 grams. The mass of sand in this sample is measured to be 1.23 g, sawdust 1.30 g , and iron 0.92 g.a. Calculate the mass percent of the sand, sawdust, and iron filings. Report answers to the hundredths place.b. What must be the mass percent of salt? Consider the accuracy ofyour answer (think in terms of the lab, not just in terms of math).c. The actual mass percent of salt is 18.49%. What is your % error?d. A larger 130.0 g SISS sample is obtained. i. What should be the percent composition of sand?

ii. What is the mass of sand in this 130.0 gram sample?

The mass of an SISS sample is 4.56 grams. The mass of sand in this sample is measured to be 1.23 g, sawdust 1.30 g , and iron 0.92 g.a.Calculate the mass percent of the sand, sawdust, and iron filings. Report answers to the hundredths place. % composition = mass of substance x 100

mass of mixture

1.23 g x 100 = 4.56 g

1.30 g x 100 = 4.56 g

0.92 g x 100 = 4.56 g

26.97% sand 20.18 % iron28.51 % sawdust

b. What must be the mass percent of salt? Consider the accuracy of your answer (think in terms of the lab, not just in terms of math).

c. The actual mass percent of salt is 18.49%. What is your % error?% error = |actual value – experimental value| x 100

actual value

% sand + % sawdust + % iron + % salt = 100%75.66% + % salt = 100% % salt = 24.34 %

1.23 g + 1.30 g + 0.92 g + x grams salt = 4.56 grams x = 1.11 g salt (then calculate mass percent)

% error = |18.49 – 24.34| x 100 18.49

31.64% error

d. A larger 130.0 g SISS sample is obtained. i. What should be the percent composition of sand? ii. What is the mass of sand in this 130.0 gram sample?

26.97 % !!!!!!!! The mass of the sand will be different. But the ratio of each of the 4 substances SHOULD BE consistent throughout the sample

% composition = mass of substance x 100mass of mixture

26.97 = x ( 100 ) 130.0g

x = 35.06 g sand

Now: Finish Separation Anxiety! If you don’t finish today, you may come to Block 7. I

don’t want to see people finishing up alone – it’s a group effort! Passes are in the black bin up front.

Some samples might not be dry – weigh them next class Hmmmm when is your Lab report due ? Read “Lab

Report FAQs”, it will answer most of your questions. Look on that handout, ask 3 people, THEN ask me, remember? I will go over lab report specifics later.

Clean up all your lab materials PERFECTLY at the end of class. If you are STILL not done, leave your labeled materials back in the fume hood.

I WILL be lecturing to help you with the packet Actual SISS

iron 21.05%sawdust 3.70%

Values (write these down)sand: 56.76%salt: 18.49%

Ms Jonson’s lab report expectations shpeel

The “Lab Report FAQs” cover most questions. This discussion will cover the highlights, but make sure you read through those before you turn in your lab.

If you have a “what if” question, the chances are that someone else does also, so please ask it TODAY

Posted on Sharepoint, and pinned up to the Clever Chemist wall, are examples of A+ lab reports to look at.

Writing the reportDo not email any part of your report to another group or

another pair. This leads to 1. plagiarism or 2. a plagiarism temptation or 3. a plagiarism accusation.

I must be able to compare the 2 or 3 reports from one group and NOTICE that the ideas and work came from different brains. I KNOW that there will be lots of similarities.

Use professional, scientific language. Avoid writing how you speak and making jokes in lab reports. Avoid the words “it” and “thing.” There are many nouns, tell me which one. “I wasn’t sure how to use the filter-thingy on the dirt, so, like, it kind of jacked up our stuff. LOL!”

Don’t simply split up the sections. Look at what your partner has written. It might be awful.

Conclusion

Number your answers. Answer the question. Leave out the fluff.

Show your work on the calculations. If I can’t understand your work, I will make you redo the report. This is one of the reasons why I require everything to by typed, including the calculations. If you have trouble using Word to superscript, subscript, etc, ask me to show you. Ex. 4 x 109 or CaCl2

It is not very easy to trick me into thinking that you know what you’re talking about when you really have no idea. I’ll know; please don’t waste my time, and yours, by being long-winded and not having a point.

Error AnalysisNo experiment is error-free. This year, we are practicing

how to identify the sources of error and analyze their impact on data. This will help you in life!!!!

Your explanation must align to the results. For example, if your mass percent of sand is 40.96% and the actual value is 26.97%, saying that you spilled some sand or MUST HAVE spilled some sand wouldn’t explain your data.

If a question says explain…then EXPLAIN…3 sentences maybe?

As you finish your experiment, jot down errors that you could have possibly made during the lab yesterday, and TODAY. Scribble ideas on your lab handout near the procedure or data table, if necessary

Formatting the ReportThe whole thing must be typed! Data Table, Procedure,

Conclusion, Error Analysis. You do not need to re-type the materials. Assemble the report in the order described on the lab handout.

Feel free to bring me a rough draft in block 7 one or two days before it’s due to make sure you’re on the right track.

I also had a busy schedule in high school. I also stayed up very late some nights because I procrastinated. These, to me, are not legitimate excuses for late or poor work.

Why would you use a crazy font? Why would you use very large or very small font? Don’t waste time on “extras”, I care about ideas….not extras. Although they are fun….

Organizing Your Lab Report

1: Cover page

Lab titleBoth namesGroup #Other namesDue date BlockOptional: picture

2a: Stamped lab handout/ prelab for person 1, then person 2, if working in pairs

3: Procedure

Please do not retype the procedure if I gave you one on the lab handout/prelab page

7: Conclusion

Please don’t spend your time retyping the questionsShow work

8: Error Analysis6: Graph(s)

Refer to ‘graphing handout’ (later) for expectationsThe lab handout will indicate if you need to do a graph

4: Data Table(s)

Type, as the one on the lab handout can get messy

Please don’t spend your time retyping the questionsShow work

Two points will be taken off if your lab report is out of order, which is the same order used by REAL SCIENTISTS. Everything doesn’t have to be on separate pages if you want to save paper, but it DOES have to be in THIS ORDER! The only thing that does not have to be typed and printed is your prelaboratory!

5: Calculations

Type these and make sure they are formatted neatly.Show your work

Turning in the reportDo not email me your lab report. If you have a printer

malfunction, you may email it to me as evidence that it was done ON TIME but that you had issues. But I will not print it out for you.

Staple it together, do not paper clip. I do not want individual pieces of your lab report. I want the whole thing, all at one time.

If you come in tardy because you were printing out your report, the report is late. Lab reports, like HW, are due before 2 minutes into class. If your lab partner has the report and has an EXCUSED absence today, the report also has an excused absence.