1. Dimensional Analysis and Conversion Factors

2. What the heck is a conversion factor? We use conversion factors to move from one unit of measurement to another One carton of eggs = 12 eggs (true fact!!) We can write 2 different conversion factors from this information: one carton or 12 eggs 12 eggs one carton

3. How do we use a conversion factor? Say eggs were on sale, so you bought 5 cartons of them. How many eggs would you have? 5 cartons x 12 eggs = 60 eggs one carton What if you needed 36 eggs for a very large omelette. How many cartons would you need? 36 eggs x one carton = 3 cartons 12 eggs

4. How does this help us in chemistry? In the lab, we may need to convert from big units to small units depending on how much of a substance we are dealing with. 1 liter = 1000 ml (another true fact!) We can write 2 conversion factors for this equality: 1 liter or 1000 ml 1000 ml 1 liter

5. Examples How many liters is 564 milliliters? 564 milliliters x 1 liter =.564 liters 1000 ml How many milliliters in 2.47 liters? 2.47 liters x 1000 ml = 2470 milliliters 1 liter

6. More Fun With Conversion Factors! We can even use conversion factors to switch between different types of measurement (for example, from volume to mass)! One liter of water weighs 1 kilogram (true fact) Therefore: _1 liter water or 1 kilogram 1 kilogram 1 liter water

7. More Fun With Conversion Factors! If the elevator was broken and you had to carry 6 liters of water up 4 flights of stairs, how much weight would you be hauling around? 6 liters water x 1 kilogram = 6 kilograms 1 liter water

8. How many minutes in a year?

9. How many seconds in September?

10. Horses are measured by “hands.” 1 hand = 4 inches 1 meter = 100 cm 1 inch = 2.54 cm A horse is 16.5 hands tall. How many meters tall is he?

11. Amoxicillin suspension is 200 mg/5 ml. A child weighs 25 lb. He needs to take an amoxicillin dose of 40 mg/kg body weight. How many ml of amoxicillin should he get? 1. Convert lbs to kg (1 kg = 2.2 lb) 2. Calculate total mg of amoxicillin needed. 3. How many ml of the suspension contains this number of mg?