Chapter 2 Measurements and Calculations

1
Chapter 2Measurements and Calculations

• Large small numbers Scientific Notation
• Measured Quantities
• Units
• Significant figures
• Temperature
• Density

2
Metric Prefixes to Know
3
Example 1

• Convert 2.25 m to
• cm
• km
• mm
• in

4
Example 2

• The distance from LA to Denver is 1182
• miles. How many kilometers is this?

5
Example 3

• A molecule is approximately 1.00 Å in
• length. How many molecules will fit
• end-to-end in a row 1.00 m long?
• 1 Å (Ångstrom) 10-10m

6
Example 4

• How many cubic centimeters are in
• 5.89102 liters?

7
Example 5

• How many cm3 are in 1.00 gallon? How
• many in3 is this?

8
Example 6

• How many grams of sodium carbonate
• are contained in a 55-lb drum?

9
Example 7

• Perform the following calculations. Be
• sure to express your answer to the
• correct number of significant figures.
• 3.45 2.8 6.333
• (7.2-8.1) / 4.72
• (3.32102)(1.110-1)
• 3.73104 5.68103

10
Example 8

• Convert 70.0F to C and to Kelvins.

11
Example 9

• If it is 28C outside, would you consider
• it a warm day or a cold day?

12
Example 10

• Express absolute zero in units of F, C,
• and K.

13
Densities of Common Substances
14
Example 11

• The density of water is 1.00 g/cm3.
• Find the density of water in units of
• kg/m3
• lb/gal

15
Example 12

• A block of metal measures 3.3 cm
• 0.51 cm 19 cm. Its mass is
• 198.662 g. What is the density of this
• metal?

16
Example 13

• An empty graduated cylinder has a
• mass of 44.113 g. When 19.6 cm3 of a
• liquid are placed in the cylinder, the
• mass of the cylinder and liquid is
• 91.552 g. What is the density of the
• liquid?

17
Example 14

• Ethanol has a density of 0.820 g/mL at
• 25C. What is the volume of 3.0 g of
• ethanol at this temperature?