Name _______________________________ Period _____
Unit 2 – Measurements, Math, & the Mole
Nothing in life is to be feared. It is only to be understood. ~Marie Curie
Essential Skills / State Standards
1. Be able to use the correct number of Significant Figures for Lab measurements and for
mathematical calculations.
2. Perform calculations using scientific notation.
3. Know that 1 mole is set by defining 1 mole of Carbon-12 atoms weighs 12 grams.
4. One mole equals 6.02 x 10 23 particles (atoms or molecules).
5. Know how to determine the molar mass of a molecule from its chemical formula and a table of atomic
masses.
6. Convert the mass of a substance to the number of moles and the number of particles.
Vocabulary Terms
Mole
Dimensional Analysis
Length
Significant figures
Molar mass
SI measurement/ units
Volume
Scientific notation
Conversion factors
Mass
Density
Extra Credit Homework Problems
Topic:
Read:
Problems:
1. Units of Measurement
p. 33-42
Section Review 2-2 p. 42 # 2, 3 (a, b, g), 4a, 5
2. Significant Figures
3. Scientific Notation
p. 46-50
p. 50-54
Section Review 2-3A p. 57 #2-4, 7-8
Section Review 2-3B p. 57 #5-6
4. The mole & molar mass
5. Counting Atoms
p. 80 - 85
p. 75 - 80
Section Review 3-3 p. 85 # 4 -7
Section Review 3-3 p. 85 #1 (a- h), 2, & 3
Study Guide
(Your labs, worksheets, and homework should also be used) **You must show all your work for credit!**
1.
Why are significant figures important to use when measuring?
2.
Record the measurement indicated with the correct number of sig. figs (both are in Cm).
3. How many significant figures are in the following? Underline them too.
a. 1000 m
b. 3025000 cm
c. 0.00740 ml
d. 8740. m
4. Write the following in scientific notation:
a. 646 002 000 000 000 km
b. .000 000 000 0215 mm
5. Write the following in ordinary notation
a. 2.036 x 105 atoms
b. 6.548 x 10-4 molecules
e. 5400.0 g
6. Perform the calculations; report your answers in both regular & sci. notation with sig figs.
a. (5400s)(3.5s)=
b.
34.95 g =
c. (6.1 x 103 g) (2.0 x 105 g)=
d. 9 x 106 cm2 =
11.169 cm3
8 x 104 cm
7. You find something that looks like a diamond that has a mass of 1.14 g and a volume of 0.56 mL. Real diamonds
have a density of 3.26 g/ml. Use Sig Figs.
a) Calculate the density of this potential diamond.
b) Is this a real diamond? How do you know?
c) Based on the density of a real diamond, will it float or sink in water? Explain.
d) What volume would a real diamond be (see density above) if it had a mass of 1.14 grams?
8. Determine the type of metric measurement in each of the following (volume, length, density, mass, area):
Abbreviation
mm
m2
ml
g ÷ L
cm
cm3
L
Unit
millimeter
Quantity
length
measured
9. Put the following metric terms in order from smallest to largest:
Meter, millimeter, kilometer, & centimeter,
10. Which metric unit would be best to measure the following?
a. the mass of a vitamin
b. the volume of a key
c. the width of a dime
11. Perform unit conversion using the SI (metric) system: show dimensional analysis/ conversion factors!
a. 4800 g to kg
b. 5 m to cm
c. 25 L to mL
d. 5 cm3 to mL
12. One mole of any substance contains ___________________ particles (aka_________number). One
mole of any substance in chemistry also has an associated mass called __________________ which can
be found on the ____________________. For example, the _________________ of C is 12.01 g/mol
while the molar mass of oxygen is __________________. The molar masses of each substance are
different because ___________________________________.
13. Calculate the molar mass of the following:
a) Ca
b) Cl2
c) CO2
d) Ca(OH)2
14. Write the “mole map” that allows you to go between grams, moles, and atoms. Include the conversion factors.
Solve the problems below using Dimensional Analysis
15. Convert the following to moles: Use Sig Figs
a) 824g of NH3
b) 43.6g of O2
c) 1.2 x 10
16. Convert the following to grams: Use Sig Figs
a) 3.00 moles of CO2
b) 0.76 moles of H2
c) 3.01 x 10
17. Given 4.50 g of CO2, how many molecules do you have? Use Sig Figs
24
molecules of CaCl2
23
molecules of H20