1. Objectives Calculate the density of a sample using mass and volume.
Solve problems in chemistry
Convert quantities using appropriate conversion factors (metric units, time, density)

2. Properties of Matter Density – The ratio of mass to volume: Examples:
What is the density of a sample with a mass of 24.9 g and a volume of 11.8 cm3?
What is the mass of a sample with a volume of 35.9 mL and a density of 2.18 g cm-3?

3. Problem-Solving
Analyze – Determine what information is known, and what information needs to be determined. Plan your solution.
Calculate – Follow your plan and develop a solution. (remember sig figs)
Evaluate – Does the answer make sense?

4. Conversions – Dimensional Analysis
Conversion factor –
A ratio of equivalent measurements.
Examples:
Use conversion factors to convert from one unit to another. The unit to be “cancelled” goes on the bottom of the conversion factor, and the unit to which you are converting goes on the top.
Sometimes you will need to make multiple conversions to solve a problem.

5. Examples Convert 1.5 m to cm. Convert 0.00064 km to mm.
Convert 3.86 years to seconds.
Convert 3.79 m/s to km/h.