Presentation on theme: "Physical & Chemical Properties & Physical & Chemical Changes"— Presentation transcript:
1 Physical & Chemical Properties & Physical & Chemical Changes P/C P/C
2 Physical Properties Identification Examples Usually a measurable characteristic you can observe without changing the chemical formula or composition such asDensity (universal p.p.)Size/ShapeColorTemperature of phase changesMelting point, boiling point, freezing point, condensation pointState of matter, Texture, Hardness, Odor, Conductivity, etc.Physical Properties of WaterDensity = 1.0 g/mLClear LiquidBoils & 100°CFreezes & 0°CPhysical Properties of AlcoholDensity = .789 g/mL, clear, liquid, BP/CP = 80°C, MP/FP = -114°CPhysical Properties of IronSolid, metallic, responds to a magnet, conducts electricity, 2750°C, etc.
3 Physical Changes Identification Examples A change in appearance (size, shape, state) without a change in the composition (chemical make up)Tearing/BreakingDissolvingPhase changes (boiling, evaporating, condensing, sublimating, depositing, melting, freezing (solidifying)Physical Changes in WaterWater freezes to form iceBreaking an icicleBoiling waterPhysical Changes in AlcoholEvaporates quicklyPhysical Changes in IronMelting iron to pour in a mold.Magnetizing an iron bar with a blow or electromagnet.
4 Chemical Properties Identification Examples The ability to react with other substancesDoesn’t mean it has changed but that it could in the right conditionsMust have been observed reacting in the past to know thisFlammabilityCorrosivityToxicity (poisonous)pHReactvityChemical Properties of WaterAbility to react with metals to from bases/corrosionAbility to react with nonmetals to form acidsChemical Properties of AlcoholFlammable (ability to burn)Toxic in moderate quantitiesChemical Properties of IronAbility to rust.
5 Chemical Changes Identification Examples A reaction where new (different) substances are formedCan be written as a chemical equationEvidence a Chemical Change occursChange in color (without dyes)Change in odorGas is produced (no heat added)Solids forming from liquids (precipitate)Spontaneous change in temperature (no heat added)Light is producedChemical Changes in WaterHydrolysis separates water into hydrogen & OxygenWater reacting with sodium to form Sodium Hydroxide and hydrogen gasChemical Changes in AlcoholAlcohol burning to form CO2 and H2O and heatChemical Changes in IronIron combining with oxygen to from rust (Fe2O3)
6 Identification TimeIdentify each of the following as either a Physical Property, Physical Change, Chemical Property or a Chemical Change:The color of the desktops are greenZinc has the ability to corrode when wetMoriah broke her bumper when she hit a deerThe food I eat is converted into waste
7 Check your lab data & notes Does a spontaneous change in temperature indicate a physical or chemical change?Which experiments resulted in a temperature change?Which ones were chemical? Physical? Why?Does a spontaneous change in color indicate a physical or chemical change?Which experiments resulted in a color change?Which ones were chemical? Physical? WhyDoes a spontaneous production of gas (bubbling) indicate a physical or chemical change?Which experiments resulted in gas production?
8 Compare/ContrastPhysical v. ChemicalProperty v. Change