270 likes | 493 Views
Chemistry Conversions. Dimensional Analysis and Atoms, Elements, Compounds. SI Prefixes. Converting From One Unit to Another. We will convert A LOT! Uses a technique called Factor Label Method Cancels out units and does the math for you!!. Factor-Label Method for Conversions.
E N D
Chemistry Conversions Dimensional Analysis and Atoms, Elements, Compounds
Converting From One Unit to Another • We will convert A LOT! • Uses a technique called Factor Label Method • Cancels out units and does the math for you!!
Factor-Label Method for Conversions • Mathematics used Numbers, rather than Quantities • Chemistry uses these same Numbers along with the value’s Units • A Number is useless without its unit • Units give the Number an actual meaning
Conversion Factors • A conversion Factor is needed to go from one unit to another • You must first know how much of one thing is of another before making any conversions • We all know 1 foot is made up of 12 inches SO… • The conversion factor needed to go from feet to inches or from inches to feet is • 1 foot / 12 inches or 12 inches / 1 foot, • Respectively.
Conversion Factors Let’s try using 1 pound = 0.454 Kilograms 1 mile = 1.61 Kilometers 1 inch = 2.54 centimeters 1 gallon = 3.71 Liters
Conversions 1 pound = 0.454 Kg 157 lb 0.454 kg 1 lb The “Heart” of the problem is where the conversion actually takes place. This is where your conversion factor does its work.
Conversions 1 pound = 0.454 Kg 157 lb 0.454 kg 1 lb ( 157 * 0.454 ) / 1 = 71 = 71 kg So yes, with the proper units 157 lb does equal 71 kg, but without units the values are not the same, as we do not know the correct representation numbers.
Units • Units are everything. They give any value an actual meaning and interpretation. • Always carry your units through, rewriting them until you reach a final value, or you will be lost.
English System (American System) Conversions Factors: • 1 foot = 12 inches • 1 yard = 3 feet • 1 mile = 5,280 feet = 1,760 yards • 1 gallon = 16 cups = 4 quarts = 8 pints • 1 pound = 16 ounces
Converting with English Units Question: Convert 15.41 yards to inches: Conversion Factors: • 1 yard = 3 feet • 1 foot = 12 inches
Converting with Metric Units Convert 15.41 yards to inches: 15.41 yd Conversion Factors: • 1 yard = 3 feet • 1 foot = 12 inches
Converting with Metric Units Convert 15.41 yards to inches: 15.41 yd 3 ft 1 yd Conversion Factors: • 1 yard = 3 feet • 1 foot = 12 inches
Converting with Metric Units Convert 15.41 yards to inches: 15.41 yd 3 ft 12in. 1 yd 1ft Conversion Factors: • 1 yard = 3 feet • 1foot = 12inches
Converting with Metric Units Convert 15.41 yards to inches: 15.41 yd 3 ft 12 in. 1 yd 1 ft = (15.4 * 3 * 12) / 1 15.41 yards = 554.76 inches
Metric System Common Metric Prefixes:
Converting with Metric Units Question: Convert 0.248 km to centimeters: Conversion Factors: • 1 Kilometer = 1000 meters • 1 meter = 100 centimeters
Converting with Metric Units Covert 0.248 km to centimeters: 0.248 km Conversion Factors: • 1 Kilometer = 1000 meters • 1 meter = 100 centimeters
Converting with Metric Units Covert 0.248 km to centimeters: 0.248 km 1000 m 1 km Conversion Factors: • 1 Kilometer = 1000 meters • 1 meter = 100 centimeters
Converting with Metric Units Convert 0.248 km to centimeters: 0.248 km 1000 m 100 cm 1 km 1m Conversion Factors: • 1 Kilometer = 1000 meters • 1 meter = 100 centimeters
Converting with Metric Units Convert 0.248 km to centimeters: 0.248 km 1000 m 100 cm 1 km 1m = (0.248 * 1000 * 100) / 1 = 24,800 centimeters Much Easier!
Calculations: Metric Vs. American System? Just count the zeros and move the decimal spot to the left or the right.