Chapter 3-1 Method, Measurement &Name ______Problem Solving Notesheets

Period _____ Date______

I. What is Chemistry?

  1. Chemistry is the study of all ______and the ______it can undergo.
  1. Chemistry has been called the ______science because it overlaps so many sciences.
  1. Chemical – any substance with a ______composition.

II. The Scientific Method: (1.3)

  1. A ______approach to gather knowledge.
  1. Steps to the Scientific Method:
  1. ______
  1. ______
  1. ______
  1. ______
  1. ______

*Note: All hypotheses must be able to be ______in order to be a true hypothesis.

C. Many Experiments  Natural Law  Theory

( ) ( )

III. Scientific Notation: Shorthand way of expressing very ______or very ______numbers.

(3.1)

A. Power of 10 Equivalent # Reason

100 ______

101 ______

102 ______

103 ______

105 ______

10-1 ______

10-3 ______

10-5 ______

B. Express Numbers in Scientific Notation – move the decimal point so that there is only ____ non-

zero digit to the left of the decimal point. Moving the decimal point left the power will be ____,

right the power will be ___.

1)2700______2) 0.0035 ______

3)2,640,000,000______4) 0.010______

C. Express Numbers in regular form– reverse the process.

5) 8.65 x 106______6) 9.73 x 10-8______

D. Know how to use scientific notation in your calculator – different for graphing + scientific!

Ex. #7) 8.08 x 10-5 – 2.07 x 10-6 =

Ex. #8) 3.7 x 102 x 5.1 x 103 =

Ex. #9) =

IV. Metric System: (3.2)

  1. International System of Measurements (SI): standard system used by all scientists. It is based upon multiples of ______.

B.Metric Units used in chemistry:

Measurement / Unit / Instrument / Equation / Derived Unit
mass / ------/ ------
length / ------/ ------
time / ------/ ------
temperature / ------/ ------
quantity / ------/ ------/ ------
area
volume
density / ------
pressure
energy / ------

C.Prefixes

Prefix / Abbreviation / Meaning / Scientific Notation
tera-
giga-
mega-
kilo-
hecto-
deka-
BASE UNIT / ------/ 1
deci-
centi-
milli-
micro-
nano-
pico-

D. Metric Conversions using the Factor-Label Method (Dimensional Analysis)

Ex. #1) Convert $72 to quarters:

Ex. #2) Convert 15 g to kg

Ex. #3) Convert 20 mL to kL

Ex. #4) Convert 0.071 m3 to Liters

Ex. #5) Convert 25 L to m3

Ex. #6) The wavelength of blue light is 450 nm convert to pm

V. Uncertainty in Measurement: (3.1)

A. Measurements are uncertain because:

  1. Instruments are not free from ______.
  1. Measuring always involves some ______.

B. Estimating with a scale

1. Estimate ______digit more than the instrument measures

2.  is used to show ______which is the last ______digit.

C. Precision: When the instrument gives you about the ______results under

similar conditions.

D.Accuracy: When the experimental value is close to the ______value. The______

the increments of measurement an instrument has, the more accurate it can be.

E.An instrument is ______(numbers repeatable to a certain number of places) the

operator makes it ______(close to the right answer by using it correctly).

Ex. Precise, Accurate, Both or Neither (Accepted Value = 15g)

  1. 200g, 1g, 40g ______

2. 78g, 80.g, 79g ______

  1. 16g, 14g, 17g ______
F. Dartboard Analogy:

VI. Significant Digits (3.1)

A. Significant Digits include ______digits and ______digits.

Use Atlantic-Pacific Rule for determining number of significant digits – see map handout.

B. Addition and Subtraction

  1. Add or Subtract numbers.
  1. Round answer to the least precise piece of equipment (look at ______places.)

Ex. 951.0 g

1407 g

23.911g

158.18 g +

B. Multiplication and Division

  1. Multiply or Divide numbers.
  1. Round answer to the least ______of significant digits.

Ex. #1) =

Ex. #2) V = L x W x H V= 3.05m x 2.10m x 0.75 m =

Ex. #3)A = L x WA= 3200cm x 2500cm =

VII. Important Formulas: (3.2)

  1. Percent Error: Comparing a measurement obtained experimentally with an ______

value. It is always expressed as a ______%.

% error =

Ex.) If a student calculates the density of aluminum to be 2.5 g/cm3, and the accepted value is

2.702 g/cm3, what was her % error?

B. Density = M=V=

Ex.) If a metal block has a mass of 75.355g and a volume of 22cm3, what is the density?

Ex.) Determine the volume of 23.249 g of nail polish remover (acetone - density of 0.791 g/mL)

VIII. Dimensional Analysis (The Factor-Label Method): (3.3)

A. Uses unit equalities to convert between ______. A unit equality is an equation that

______2 units. Ex.) 12in = 1 ft60sec = 1 min1kg = 1000g

B. Unit equalities are used to write ______which are always

equal to “1.”Ex) = 1 or = 1

C. The conversion factor is a definition, and therefore infinitely precise, so the number of significant

digits in the answer is equal to the number in the ______which is the ______value.

Useful Chemistry Conversion Factors
1 in. = 2.54 cm / 1 atm = 760 mm Hg
1 ft. = 12 in. / 1 atm = 101,325 Pa
1 mile = 5280 ft. / 1 cal. = 4.184 J
1 min. = 60 s / 1 Cal = 1000 cal
1 hr. = 60 min. / 1 gal. = 3.785 L

Ex. #1) How many seconds are in 22 hours?

Ex. #2) How many years are 3 x 108 seconds?

Ex. #3) If there are 9 dibs in 1 sob, 3 sobs in 1 tog, 1 tog in 6 pons, and 12 pons in 1 gob. How many

gobs are in 27 dibs?

Ex. #4) Calculate the number of feet in a 5.00 km race. (1 inch = 2.54 cm)

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