Presentation on theme: "Measurement in Chemistry"— Presentation transcript:
1 Measurement in Chemistry SI (Metric System) UnitsPrefixesFactor Label MethodEquipmentUsing density for identification and applications
2 2. Measurement in Chemistry Measurements in chemistry always require a ________________ & a ________________.NO ___________________ numbers!We use the International System (SI), which is similar to the metric system:
3 SI Units Quantity Common unit Measurement Equipment Mass Length Time Temperature
5 SI Units Quantity Common Unit Measurement Equipment Amount of SubstanceEnergyVolume of a LiquidVolume of aSolid
6 Small and large units Metric System: Similar system but using prefixes Everyday units (English System)LengthPaperclip:LaptopWhiteboardSandy Porter RoadMetric System: Similar system but using prefixes
7 Small and large measurements SI System: Based on Powers of Ten
8 Important SI Prefixes Kilo- k Hecto h Deka- da Base Decid Centi- c Milli-m10001001010.10.010.00110³10²10¹10°10⁻¹10⁻²10⁻³1 meter1 Liter1 gram
9 Equivalent amounts - Memorize! 1 kilometer (_____) = _______ meters1 hectometer ( ) = ________ meters1 dekameters ( ) = ________ meters1 meter = ________ decimeters1 meter = ________ centimeters1 meter = ________ millimeter
10 Memory tool: King Henry Died by Drinking Chocolate Milk
11 Measurements in chemistry calculations must have the same ____and ______. To covert:Given Quantity x Conversion Factor = Unknown (or desired) QuantityA known beginning=A desired end=A connecting path=
12 Factor Label MethodPlease note: There are other ways to do the metric conversions. However, the following method will be used in chemistry to help prepare for the more difficult mole calculations, which will be in the next unit. Use the other methods to check your answers.
13 The most important mathematical process in chemistry! Factor Label MethodThe most important mathematical process in chemistry!A known beginning = GIVENA desired end= UNKNOWNA connecting path = CONVERSION FACTOR
14 Conversion Factor Uses equal quantities 60 seconds = 1 minute 1 km = 1000 metersConversion factors can be written as ratiosRatios are written as “tops or bottoms” depending on the units to be cancelled.
15 Example: How many centimeters are in 6.4 meters?
16 1. How many grams are in 463 kilograms? Given: Unknown: Example Problems: Given quantity & unit x Unknown unit = Unknown quantity & unit Given unit1. How many grams are in 463 kilograms?Given:Unknown:Conversion factor:Solve:
17 2. How many milliliters are in 2.5 liters? Given: Unknown: Example Problems: Given quantity & unit x Unknown unit = Unknown quantity & unit Given unit2. How many milliliters are in 2.5 liters?Given:Unknown:Conversion factor:Solve:
18 3. How many meter(s) are equal to 16 centimeters? Given: Unknown: Example Problems: Given quantity & unit x Unknown unit = Unknown quantity & unit Given unit3. How many meter(s) are equal to 16 centimeters?Given:Unknown:Conversion factor:Solve:
19 Factor Label - Multiple steps example Calculate the number of seconds in one day.60 seconds = 1 minute60 minutes = 1 hour24 hours = 1 dayGiven Desired = sec1 day hr. 60 min. 60 sec =1 day hr min.
20 If you are changing prefixes for a measurement: Size of the number (quantity)SmallBigS ↔ BLargerPrefix forthe UnitUnit PrefixSmaller Prefix for the UnitDouble check your answers!