Chemistry: THE STUDY OF MATTER. So what is matter? So what is matter?
Chemistry Copy: S SO
Transcript of Chemistry Copy: S SO
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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