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Chemistry Monday, January 23, 2017

Do-Now: “Ch. 11 Quiz Review” 1. Write down today’s FLT 2.  List three symbols used in chemical

equations, and state their meaning. 3.  Copy: S8 + O2 à SO2 4.  Identify the type of reaction in #3. 5.  Balance the equation in #3. Show all work.

Take out your planner and ToC

Announcements •  Scien&ficcalculators!• A2endtutoringasneeded• Usedojopoints• Reminder:retakes

– Bringquizzesyouwishtoretake– Clearmissingwork

Planner: •  Read Ch. 3 •  Bring calculators! •  Lab Safety: hair tied back + close-toed

shoes

Table of Contents #1: 10. Ch. 11 Quiz Review Do-Now

FLT •  I will be able to demonstrate my

understanding of chemical reactions by completing Ch. 11 Quiz

Standard HS-PS1-7:Usemathema2calrepresenta2onstosupporttheclaimthatatoms,andthereforemass,areconservedduringachemicalreac2on

Quiz Protocol • Clearyourdesks• Noiselevel0• Eyesonyourownpaper• Checkanswerswhenfinished• Flipoverwhenfinished

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CW • ReadCh.3

Chemistry Tuesday, January 24 – Wednesday, January

25, 2017

Do-Now: “Lab Day” On the back of your packets:

1. Write down today’s FLT 2.  List at least 8 important things to remember

in the lab. These can include safety rules, how to dress, and how to clean after.

3.  Start reading over the lab.

Take out your planner and ToC

Announcements •  Scien&ficcalculators!• A2endtutoringasneeded• Usedojopoints• Retakes

–  Beforeschool–  Lunch– ALerschoolbyappointmentonly(Tues/Thurs)

Planner: •  Finish lab packets and turn in to HW box •  Bring calculators •  Retake quiz (if needed)

Table of Contents #1: 10. Ch. 11 Quiz Review Do-Now

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FLT •  I will be able to observe the signs of

chemical reactions by completing Reaction Lab

Standard HS-PS1-7:Usemathema2calrepresenta2onstosupporttheclaimthatatoms,andthereforemass,areconservedduringachemicalreac2on

Some Signs of a Chemical Rxn 1.   Produc&onofanodor2.   Changeintemperature

3.   Changeincolor4.   Forma&onofbubbles

5.   Forma&onofasolid

Lab Overview 1.   Hairmustbe&edback

2.   Gogglesmustbeon

3.   Weargloves

4.   Holdtongscarefully5.   Rinseoutmaterialsateachsta&on

beforemovingtothenext

6.   Recordverydetailedobserva&ons

Lab Overview Twotypesofobserva&ons:

Qualita&ve=usesthe5senses

“Thebeakerfeelswarm”“Thesolu2onlookscloudy”

Quan&ta&ve=usesnumbers/

measurements

“Iadded10drops”“Themasswas4.6grams”

CW • Post-LabQues&ons• ReadCh.3

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Chemistry Thursday, January 26 – Friday, January 27,

2017

Do-Now: “Cornell Notes Ch.3 A” 1. Write down today’s FLT 2. What is 466.034160 rounded to the

nearest… a.  Hundredths b.  Tenths c.  Ones d.  Tens e.  Hundreds

3. Why do you think we round numbers? 4.  Turn in your labs if finished.

Take out your planner and ToC

Announcements •  Scien&ficcalculators!• A2endtutoringasneeded• Usedojopoints• Reminder:retakes

– Bringquizzesyouwishtoretake– Clearmissingwork

Planner: • Ch. 3 Quiz next week (short chapter) • Get stamps!

Table of Contents #1: 11. Ch. 3 A Cornell Notes 12.  Sig Figs Packet

FLT •  I will be able to determine the number

of significant figures in a measurement by completing Ch. 3 A Notes

Standard HS-PS1-7:Usemathema2calrepresenta2onstosupporttheclaimthatatoms,andthereforemass,areconservedduringachemicalreac2on

Ch. 3: Scientific Measurement

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Ch. 3 A Cornell Notes • Add assignment # • Copy down all bolded ideas • Noise level 0 • Raise hand to question/comment • Be prepared to pair-share-respond

Measurements

Measurements • We often take measurements in

chemistry labs

Measurements •  Are our measurements accurate? •  This depends on:

– The reliability of the measuring instrument – the care with which it is read – this is

determined by YOU!

Measurements •  Video Notes

– Write down four facts or examples from the video clip

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Accuracy vs. Precision

Accuracy, Precision, and Error §  It is necessary to make good, reliable

measurements in the lab § Accuracy – how close a measurement

is to the true value § Precision – how close the

measurements are to each other (reproducibility)

Precision and Accuracy

Neither accurate

nor precise

Precise, but not accurate

Precise AND

accurate

WhyIsthereUncertainty?•  Measurements are performed with instruments, and no instrument can read to an infinite number of decimal places • Which of the balances below has the greatest uncertainty in measurement?

A Brief Review of Scientific Notation Sig Figs

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Significant Figures in Measurements

§ Significant figures = all known digits plus one estimated digit

§ Measurements must be reported to the correct number of significant figures.

Significant Figures in Measurements

§ If you don’t use the correct sig figs, your answer is incorrect L

Rules for Sig Figs

Rules for Counting Sig Figs

-Nonzero digits are always significant

Ex/ 3456 4 sig figs

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Rules for Counting Sig Figs

-Leading zeroes are NOT significant

Ex/ 0.0486 3 sig figs

Rules for Counting Sig Figs

-Zeroes in between significant digits are also significant

Ex/ 16.07

4 sig figs

Rules for Counting Sig Figs Trailing zeroes are significant if they

are before or after a decimal point

Ex/ 9.300 4 sig figs

Ex/ 0.03010 4 sig figs

Rules for Counting Significant Figures

Counted items & defined quantities have unlimited sig figs

• Counted items –  23 people, or 425 thumbtacks

•  Exactly defined quantities –  60 minutes = 1 hour

M x 10n

1 ≤ M < 10 n is an integer

Pair-Share-Respond How many significant figures in the following?

1.0070 m à 5 sig figs

17.10 kg à 4 sig figs

100,890 L à 5 sig figs

3.29 x 103 s à 3 sig figs

0.0054 cm à 2 sig figs 3,200,000 mL à 2 sig figs

5dogsà unlimitedThis is a counted value

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Significant Figures in Calculations

§  In general a calculated answer cannot be more precise than the least precise measurement from which it was calculated.

§ Ever heard that a chain is only as strong as the weakest link?

§ Sometimes, calculated values need to be rounded off.

Rounding Calculated Answers

1.  Determine how many sig figs are needed 2.  Round your answer to the correct

number of sig figs

Rounding Calculated Answers

§ + and - § Round to the number with the fewest decimal places

Ex/12.25 m + 349.0 m + 8.24 m 369.5 m

Rounding Calculated Answers § × and ÷ § Round answer to the smallest

# of sig figs present

• Ex/ 6.38 x 2.0 = • 12.76 • à 13 (2 sig figs) § Ex/2.10 meters x 0.7 meters § = 1 meter

Pair-Share-Respond

3.24 m x 7.0 m Calculation Calculator says: Answer

22.68 m2 23 m2

100.0 g ÷ 23.7 cm3 4.219409283 g/cm3 4.22 g/cm3

0.02 cm x 2.371 cm 0.04742 cm2 0.05 cm2

710 m ÷ 3.0 s 236.6666667 m/s 240 m/s

1818.2 lb x 3.23 ft 5872.786 lb·ft 5870 lb·ft

1.030 g x 2.87 mL 2.9561 g/mL 2.96 g/mL

CW • SigFigPacket• ToCand/orstudyCh.3