Dimensional analysis-measuring-data analysis.pdf

PPT about dimensional analysis and unit conversion.

1. Dimensional Analysis
Measuring and Data Analysis

2. Dimensional Analysis
▪Problem-solving method focused on
units that describe matter and their
relationships.
▪Often uses conversion factors.

3. Conversion factors
▪Ratio of equivalent values that express the
same quantity in different units.
▪Always equal to 1
▪Changes units without changing magnitude.
https://assets.katomcdn.com/q_auto,f_auto/products/007/007-3216/007-3216.jpg

4. Measuring
▪Comparing a quantity with its
corresponding unit, so it is possible
to determine how many times the
unit is contained in this quantity.
“medir." Diccionario de la Lengua Española – 22a ed. 2001. Real Academia Española. 04 Aug. 2008 <http://buscon.rae.es/draeI>

5. Measuring systems
▪English system (British Imperial System)
– around 1220

▪Metric system (decimal) – 1790

▪International System of Units (SI) - 1960
“Measurement system." Encyclopædia Britannica. 2008. Encyclopædia Britannica Online. 04 Aug. 2008 <http://www.britannica.com/EBchecked/topic/1286365/measurement-system>.

6. Measuring systems
▪Base units: based on objects or events
from the physical world.

▪Derived units: combinations of base
units.

Dingrando, Laurel, Kathleen Tallman, Nicholas Hainen, Cheryl Wistrom et al. Chemistry; Matter and Change. Columbus, Ohio: Glencoe/McGraw Hill, 2005

7. Fundamental quantities / base units
▪Lenght: meter (m)
▪Mass: kilogram (kg)
▪Time: second (s)
▪Thermodynamic temperature: kelvin (K)
▪Amount of substance: mole (mol)
▪Luminous intensity: candela (cd)
▪Electric current: ampere (A)

8. Prefixes for SI units
Dingrando, Laurel, Kathleen Tallman, Nicholas Hainen, Cheryl Wistrom et al. Chemistry; Matter and Change. Columbus, Ohio: Glencoe/McGraw Hill, 2005

9. Examples
Dingrando, Laurel, Kathleen Tallman, Nicholas Hainen, Cheryl Wistrom et al. Chemistry; Matter and Change. Columbus, Ohio: Glencoe/McGraw Hill, 2005

10. Exercises
Dingrando, Laurel, Kathleen Tallman, Nicholas Hainen, Cheryl Wistrom et al. Chemistry; Matter and Change. Columbus, Ohio: Glencoe/McGraw Hill, 2005

11. Exercises
Dingrando, Laurel, Kathleen Tallman, Nicholas Hainen, Cheryl Wistrom et al. Chemistry; Matter and Change. Columbus, Ohio: Glencoe/McGraw Hill, 2005

12. Exercises

13. What volume is occupied by 16.4 g of mercury?
The density of mercury is 13.6 g/mL.

14. A 3.2 cm-edge cube has a mass of 450 g.
Calculate its density in lb/in
3

15. A 50-mL graduated cylinder was filled with 15.9 mL of water. 30.0 g of
an unknown metal (in the form of small pellets) was added to the
graduated cylinder, causing the water level to rise to 17.3 mL. The
possible identities of the metal are aluminum (d = 2.70 g/cm3), iron (d
= 7.78 g/cm3), magnesium (d = 1.74 g/cm3), tin (d = 7.26 g/cm3),
platinum (d = 21.5 g/cm3), beryllium (d = 1.85 g/cm3), or copper (d =
8.94 g/cm3). Identify the metal.

16. Calculate the molar mass for the following compounds :




H
2
SO
4

As
2
O
3

C
12
H
22
O
11

Ca
3
(PO
4
)
2

HClO
3

98 g/mol
198 g/mol
342 g/mol
310 g/mol
84.5 g/mol
Calculating molar mass

18. … has a mass equal to the atomic (if
elements) or molecular (if compounds)
mass expressed in grams
Molar mass
(variable)
… contains
6.022x10
23
particles
(atoms if element, molecules if
compound or molecular element)
Avogadro’s number
(constant)
… occupies a volume of
22.4 liters
(only for gases at STP*)
Molar volume
(constant)
One
Mole…
*STP = Standard
Temperature (0°C = 273.15 K) and
Pressure (1 atm = 760 mmHg = 101.3 kPa)

19. Mole conversions
1.How many molecules are in 3 moles of
Al
2
(SO
4
)
3
?

2.How many moles are in 200 g of Fe
2
O
3


3.Determine the amount of molecules in 100
g of HgClO
2

20. Mole conversions
1.How many molecules are in 3 liters at STP
of H
2
S
(g)
?

2.How many molecules are in 340 g of
H
2
SO
3


3.Determine the amount of moles in
1.45x10
26
molecules of HCl

21. Temperature Scales
“Temperature scales.” 04 Aug. 2008 http://abyss.uoregon.edu/~js/glossary/temperature_scale.html

22. Temperature Scales
“Temperature scales.” 04 Aug. 2008 http://abyss.uoregon.edu/~js/glossary/temperature_scale.html

23. Temperature Scales
180°
“Temperature scales.” 04 Aug. 2008 http://abyss.uoregon.edu/~js/glossary/temperature_scale.html

24. Temperature Scales
180° 100°
“Temperature scales.” 04 Aug. 2008 http://abyss.uoregon.edu/~js/glossary/temperature_scale.html

25. Temperature Scales
180° 100° 100°
“Temperature scales.” 04 Aug. 2008 http://abyss.uoregon.edu/~js/glossary/temperature_scale.html

26. Scientific Notation
▪Numbers as multiple of two factors:
1 to 9 and10
n

▪Larger than 1: n = (+)
▪Smaller than 1: n = (-)
▪Adding and substracting: SAME
exponents!
▪Multiplying: multiply factors, then add
exponents.
▪Dividing: divide factors, then substract
exponents.
Dingrando, Laurel, Kathleen Tallman, Nicholas Hainen, Cheryl Wistrom et al. Chemistry; Matter and Change. Columbus, Ohio: Glencoe/McGraw Hill, 2005

27. Exercises
Dingrando, Laurel, Kathleen Tallman, Nicholas Hainen, Cheryl Wistrom et al. Chemistry; Matter and Change. Columbus, Ohio: Glencoe/McGraw Hill, 2005

28. Exercises
Dingrando, Laurel, Kathleen Tallman, Nicholas Hainen, Cheryl Wistrom et al. Chemistry; Matter and Change. Columbus, Ohio: Glencoe/McGraw Hill, 2005

29. Exercises

30. Exercises
Dingrando, Laurel, Kathleen Tallman, Nicholas Hainen, Cheryl Wistrom et al. Chemistry; Matter and Change. Columbus, Ohio: Glencoe/McGraw Hill, 2005

31. References
Dingrando, Laurel, Kathleen Tallman, Nicholas Hainen,
Cheryl Wistrom et al. Chemistry; Matter and Change.
Columbus, Ohio: Glencoe/McGraw Hill, 2005
“Measurement system." Encyclopædia Britannica. 2008.
Encyclopædia Britannica Online. 04 Aug. 2008
<http://www.britannica.com/EBchecked/topic/1286365/
measurement-system>.
“medir." Diccionario de la Lengua Española – 22a ed.
2001. Real Academia Española. 04 Aug. 2008
http://buscon.rae.es/draeI
“Temperature scales.” 04 Aug. 2008
http://abyss.uoregon.edu/~js/glossary/temperature_sca
le.html

32. Measuring…
1.Choose someone to work with today.
2.Take your notebook and pencil and/or mobile
device with you.
3.Go out from the classroom and measure 10
different things using only the tools you have
(notebook/pencil/mobile device). Write down
the measurements. You will have 15 minutes
to do this.
4.Come back to the classroom to share your
results.

33. http://learningfundamentals.com.au/resources/