2 data 2011

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unit 2 of the chemistryadventure series

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2 data 2011

  1. 1. Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error<br />SI Units: Le SystemeInternationale<br />Unit 2: Data<br />Identify the 7 common SI units:<br />Kelvin<br />temperature<br />Ampere<br />k<br />current<br />second<br />s<br />time<br />A<br />mole<br />meter<br />amount<br />mol<br />m<br />distance<br />candela<br />brightness<br />cd<br />kg<br />kilogram<br />mass<br />Combined Units:<br />speed<br />acceleration<br />density<br />volume<br />Density formula:<br />1<br />
  2. 2. Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error<br />Unit 2: Data<br />Density calculations<br />13.5 g of aluminum has a volume of 5 mL. Density?<br />What is the mass of 2 mL of aluminum?<br /><ul><li>m = vd
  3. 3. = (2 mL)(2.7 g/mL)
  4. 4. = 5.4 g</li></ul>divide<br />m<br />multiply<br />d<br />v<br />2<br />
  5. 5. Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error<br />Unit 2: Data<br />Billion (109)<br />Giga (G)<br />2. Prefixes<br />Mega (M)<br />Million (106)<br />List the common unit prefixes and their abbreviations<br />kilo (k)<br />Thousand (103)<br />learn more<br />1<br />Hundredth 10-2<br />centi (c)<br />milli (m)<br />Thousandth (10-3)<br />micro (m)<br />Millionth (10-6)<br />3<br />nano (n)<br />Billionth (10-9)<br />
  6. 6. Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error<br />Temperature<br />Unit 2: Data<br />When is Kelvin normally used and why?<br />Kelvin<br />Temp scale that cannot go below zero:<br />K to 0C:<br />25oC = ?K<br />K = oC +273<br />= 298 K<br />In many formulas: it is mathematically accurate.<br />0F to 0C:<br />°C= (°F - 32) × 5/9°F = ° C× 9/5 + 32 <br />-40oC = ?0F<br />x9 = -360, /5 = -72, + 32 = -40 0F <br />-40oF = ?0C<br />-32 = -72, x5 = -360, /9 = -40 = -40 0C <br />4<br />4<br />
  7. 7. Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error<br />Scientific Notationfor big and small numbers<br />Example:<br />Try some:<br />= 2.12 x 102<br />212<br />.0097<br />10,000<br />= 9.7x 10-3<br />= 1 x 104<br />602,000,000,000,000,000,000,000<br />Draw a line to make it between 1 and 10; count to decimal point.<br />Always 10x<br />Always 1-10<br />= 6.02x 1023<br />-2860<br />= -2.86 x 103<br />= 9.742 x 10-4<br />.0009742<br />5<br />
  8. 8. Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error<br />Scientific Notation on your calculators: 2 methods<br />Enter 6.02 x 1023<br />For fancy calculators (like TI-83, etc)<br />For cheaper calculators that don’t do ()<br />Enter it all in parentheses- you’ll need them<br />Use EE button, no parentheses needed<br />Enter (6.02x10^23)<br />Enter 6.02E23<br />Example: what is (2 x 101)(1 x 101)?<br />Enter (2 x 10^1)(1 x 10^1)<br />Enter 2E1x1E1<br />= 200 or 2E2<br />Try this: (3 x 10-2) x (-4.2 x 10-4) = ?<br />Enter (3x10^-2)x(-4.2x10^-4)<br />Enter 3E-2x-4.2E-4<br />Negative, not subtract<br />Negative, not subtract<br />Add answer<br />= -1.26 x 10-5 or -0.0000126<br />6<br />
  9. 9. Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error<br />5. ConversionsA Sample Problem<br />You have $7.25 in your pocket in quarters. How many quarters do you have?<br />1. Start with<br />What you are<br />given<br />3. Multiply using<br />Conversion factors<br />To get there<br />2. Write the units <br />you need to<br />Get to<br />4 quarters<br />29<br />= ___ quarters<br />X<br />7.25 dollars<br />dollar<br />Cancel your units to prove you did it correctly.<br />7<br />
  10. 10. 1. Units 2. Prefixes 3. Dens./temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error<br />Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error<br />Convert 65 miles/hour to meters per second<br /><ul><li>(1609 meters = 1 mile; 3600 seconds = 1 hour</li></ul>1. Start with<br />What you are<br />given<br />3. Multiply using<br />Conversion factors<br />To get there<br />2. Write the units <br />you need to<br />Get to<br />1609 meters<br />1 hour<br />65 miles<br />x<br />x<br />meters<br />second<br />= 29.05<br />hour<br />1 mile<br />3600 seconds<br />Cancel your units to prove you did it correctly.<br />Slightly Harder Conversions<br />8<br />
  11. 11. Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error<br />6. Significant Figures<br />1. When measuring<br /> include the known digits plus one estimated digit.<br />Volume?<br />32.0 mL<br />9<br />
  12. 12. Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error<br />Significant Figures: Guess which zero’s matter (L1 only)<br />number<br />why<br /># SIG. FIGS:<br />1. “non-zero numbers are always significant”<br />32<br />2<br />2. “leading zeroes are <br />Never significant”<br />0.0323<br />3<br />3. “sandwiched zeroes are <br />always significant”<br />3.004<br />4<br />300<br />1<br />4. “trailing zeroes are only significant if there is a decimal place”<br />300.<br />3<br />5<br />300.20<br />.030690<br />Summary:<br />Keep if decimal present<br />dump<br />10<br />keep<br />
  13. 13. Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error<br />Learning Check INCLUDE add subtract multiply divide add graph to formula slide<br />A. Which 2 answers contain 3 significant figures?<br />1) 0.4760 2) 0.00476 3) 4760 <br />B. All the zeros are significant in <br /> 1) 0.00307 2) 25.300 3) 2.050 x 103<br />C. 534,675 rounded to 3 significant figures is<br /> 1) 535 2) 535,000 3) 5.35 x 105<br />> or = 5; round up<br />11<br />
  14. 14. 7. Percent Error<br />Data: 1.Units2. Prefixes 3. temp. 4. Sci. not. 5. Conversions 6. sig. fig.’s 7. % error<br />You measure your mass to be 120 lbs,<br /> but in reality it is 150 lbs. What is your percent error?<br />Add images, perhaps a video, etc.<br />= 30 lbs/150 lbs x 100<br />= 20%<br />End data unit <br />12<br />

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