**
Example 1
**

What is the volume in liters?

What is the weight if the specific density is 1.1?

How many moles of water are present if all the weight is due to water?

How many moles of H (not H

How many H atoms are present in the ocean?

*Solution*

1000 m 10 dm 1.4e9 (------)^{3}(------)^{3}1 km 1m 1 L = 1.4e21 dm^{3}(----) 1 dm^{3}1.1 kg = 1.5e21 L(------) 1 L 1000 g 1 mol = 1.5e21 kg (------)(-----) 1 kg 18 g 2 mol H atoms = 8.3e22 mol H_{2}O (---------------) 1 mol H_{2}O 6.02e23 atoms = 1.7e23 mol H (-------------) 1 mol = 5.0e46 H atoms

*Discussion*

Even in this simple example, several concepts such as the quantity in mole, Avogadro's number, and specific density (or specific gravity) have been applied in the conversion. If you have not learned these concept, you may have difficulty in understanding some of the conversion processes. Identify what you do not know and find out in your text or from a resource.

**
Example 2
**

*Solution*

km 1000 m 1 hr 1 min 50 -- (------) (------) (-----) = 13.89 m/s hr 1 km 60 min 60 sThus, 50 km/hr is faster.

*Discussion*

**
**

*Solution*

$ 1 kg 4.99 -- (-----------) = 2.26468 $/lb kg 2.206532 lb

*Discussion*