chemical vs. physical properties. review physical vs. chemical changes
TRANSCRIPT
Chemical vs. Physical Properties
Review Physical vs. Chemical Changes
• Chemical Property:– Describes reactions
• What a chemical will react with• When a chemical will react• How a chemical reacts
• Physical Property:– Describes physical changes
• Temperatures phase changes occur• What it will dissolve in• If it will bend or crumble when hit (malleable or brittle)
– Describes static characteristics• Color• Smell• density
Water’s Properties
• Physical Properties of Water:– Boils at 100 degrees C– Freezes at 0 degrees C– Transparent and clear– Odorless– Density of 1 g/mL
• Chemical Properties of Water:– Unreactive with water– Reacts when electrocuted to form gasses
On your group’s white-board/paper, list the Chemical Properties of iron in one column. List
the Physical Properties of iron in a different column.
• Example Scenario:– Iron is a relatively soft, shiny, gray, solid at room
temperature.
Example Scenario:– Iron is a relatively soft, shiny, gray, solid at room
temperature. It conducts electricity, is magnetic, and has a density of 7.9 g/ml at room temperature. As a solid, it will not dissolve in any liquid. However, It melts at 28000F, and will mix with melted carbon to form a mixture called steal. Similar alloys can be made my mixing melted iron with melted nickel, chromium, or manganese. Iron typically reacts slowly with oxygen or water to form rust, a flaky solid. It also bonds to oxygen in our blood, giving our blood that red color, and speeds up reactions in our cells.
On your group’s white-board/paper, do the same thing with sugar!
– Sugar has a density of 1.6 g/mL. It would melt at 367 degrees Fahrenheit, if it didn’t react first with the oxygen, producing carbon dioxide and water, and releasing a lot of heat. Sugar also reacts with potassium nitrate to form home-made rocket fuel, and sulfuric acid can separate the carbon atoms from the hydrogen and oxygen atoms in sugar, causing a “dehydration reaction”.
MeasurementsCharacteristic Units equipment
Mass
Length or Height
Volume
Time
Temperature
pH
Characteristic Units equipment
Mass Grams (g) Balance or Scale
Length or Height
Volume
Time
Temperature
pH
Characteristic Units equipment
Mass Grams (g) Balance or Scale
Length or Height Meters (m) Ruler, Meter Stick
Volume
Time
Temperature
pH
Characteristic Units equipment
Mass Grams (g) Balance or Scale
Length or Height Meters (m) Ruler, Meter Stick
Volume Liters (L)Centimeters cubed (cm3 )
Graduated Cylinder
Ruler & Calculate
Time
Temperature
pH
Characteristic Units equipment
Mass Grams (g) Balance or Scale
Length or Height Meters (m) Ruler, Meter Stick
Volume Liters (L)Centimeters cubed (cm3 )
Graduated Cylinder
Ruler & Calculate
Time Seconds (s) Stop-watch
Temperature
pH
Characteristic Units equipment
Mass Grams (g) Balance or Scale
Length or Height Meters (m) Ruler, Meter Stick
Volume Liters (L)Centimeters cubed (cm3 )
Graduated Cylinder
Ruler & Calculate
Time Seconds (s) Stop-watch
Temperature Degrees (0F or 0C) Thermometer
pH
Characteristic Units equipment
Mass Grams (g) Balance or Scale
Length or Height Meters (m) Ruler, Meter Stick
Volume Liters (L)Centimeters cubed (cm3 )
Graduated Cylinder
Ruler & Calculate
Time Seconds (s) Stop-watch
Temperature Degrees (0F or 0C) Thermometer
pH none Litmus paper
Density is a physical property.
formula• Density = units
equipment
• How to determine density:
• Measure volume with graduated cylinder• Or• Measure lengths with ruler and calculate
• And Measure mass with a balance.
• Then Divide: Mass / Volume = Density