Presentation on theme: "Physical & Chemical Properties & Physical & Chemical Changes."— Presentation transcript:
Physical & Chemical Properties & Physical & Chemical Changes
Physical Properties IdentificationExamples Usually a measurable characteristic you can observe without changing the chemical formula or composition such as Density (universal p.p.) Size/Shape Color Temperature of phase changes Melting point, boiling point, freezing point, condensation point State of matter, Texture, Hardness, Odor, Conductivity, etc. Physical Properties of Water Density = 1.0 g/mL Clear Liquid Boils & 100°C Freezes & 0°C Physical Properties of Alcohol Density =.789 g/mL, clear, liquid, BP/CP = 80°C, MP/FP = -114°C Physical Properties of Iron Solid, metallic, responds to a magnet, conducts electricity, 2750°C, etc.
Physical Changes IdentificationExamples A change in appearance (size, shape, state) without a change in the composition (chemical make up) Tearing/Breaking Dissolving Phase changes (boiling, evaporating, condensing, sublimating, depositing, melting, freezing (solidifying) Physical Changes in Water Water freezes to form ice Breaking an icicle Boiling water Physical Changes in Alcohol Evaporates quickly Physical Changes in Iron Melting iron to pour in a mold. Magnetizing an iron bar with a blow or electromagnet.
Chemical Properties IdentificationExamples The ability to react with other substances Doesn’t mean it has changed but that it could in the right conditions Must have been observed reacting in the past to know this Flammability Corrosivity Toxicity (poisonous) pH Reactvity Chemical Properties of Water Ability to react with metals to from bases/corrosion Ability to react with nonmetals to form acids Chemical Properties of Alcohol Flammable (ability to burn) Toxic in moderate quantities Chemical Properties of Iron Ability to rust.
Chemical Changes IdentificationExamples A reaction where new (different) substances are formed Can be written as a chemical equation Evidence a Chemical Change occurs Change in color (without dyes) Change in odor Gas is produced (no heat added) Solids forming from liquids (precipitate) Spontaneous change in temperature (no heat added) Light is produced Chemical Changes in Water Hydrolysis separates water into hydrogen & Oxygen Water reacting with sodium to form Sodium Hydroxide and hydrogen gas Chemical Changes in Alcohol Alcohol burning to form CO2 and H2O and heat Chemical Changes in Iron Iron combining with oxygen to from rust (Fe2O3)
Identification Time Identify each of the following as either a Physical Property, Physical Change, Chemical Property or a Chemical Change: The color of the desktops are green Zinc has the ability to corrode when wet Moriah broke her bumper when she hit a deer The food I eat is converted into waste
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? Why Does a spontaneous production of gas (bubbling) indicate a physical or chemical change? Which experiments resulted in gas production? Which ones were chemical? Physical? Why?
Compare/Contrast Physical v. ChemicalProperty v. Change