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Objectives. PSc.2.1.3 Compare physical and chemical properties of various types of matter. Physical Properties. Physical properties are characteristics that a sample of matter exhibits without any change in its identity.
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Objectives PSc.2.1.3 Compare physical and chemical properties of various types of matter.
Physical Properties Physical properties are characteristics that a sample of matter exhibits without any change in its identity. This property can be observed and measured without changing the identity of the substance.
Examples of the physical properties of a chunk of matter include its: Physical Properties • boiling point • solubility • density • melting point • magnetic • color • electrical conductivity • and physical state (solid, liquid or gas)
Salt is soluble in water. Physical Properties • Water boils at 100°C.
Chemical Properties • Chemical Properties are properties of matter that describes a substance’s ability to participate in chemical reactions. • A chemical property describes how a substance changes into a new substance, either by combining with other elements or breaking apart into new substances.
Chemical Properties • Examples: • Reactivity- the ability of a substance to combine chemically with another substance. • Flammability- the ability of a substance to react in the presence of oxygen and burn when exposed to a flame. • In general, the ability of a substance to…
Chemical Properties • You can observe chemical properties only in situations in which the identity of the substance changes.
Physical vs. Chemical Prop. • Classify the following properties as either chemical or physical.
Density Density is the amount of matter (mass) contained in a unit of volume. Styrofoam has a low density or small mass per unit of volume.
Density m V D
Solving Density Problems Cover the variable you are solving for If you cover the top variable, multiple the bottom ones Density m V D To solve for mass, multiply volume by density.
Solving Density Problems Cover the variable you are solving for If you cover a bottom variable, take the top variable and divide by the bottom Density m V D To solve for volume, take mass and divide by density.
m V D • Calculate the mass for an object having a density of 19 g/mL and a volume of 5.0 mL. GIVEN: D = 19 g/mL V= 5.0 mL m = ? WORK: m =V x D m = (19 g/mL) (5.0 mL) m = 95 g
m V D • Calculate the volume for an object having a mass of 18 g and a density of 12 g/mL. GIVEN: m = 18 g D = 12 g/mL V = ? WORK: V = m ÷ D V = (18 g) ÷ (12 g/mL) V = 1.5 mL
Density Solve the following density problems. 1. The density of sugar is 1.59 g/cm3. Calculate the mass of sugar in 15.0 mL. (1 mL = 1 cm3) 23.9 g
Density 2. The density of helium is 0.178 g/L. Calculate the volume of helium that has a mass of 23.5 g. 132 L
Density 3. A 14.95 g sample of gold has a volume of 0.774 cm3. Calculate the density of gold. 19.3 g/cm3
Density 4. Balsa wood has a density of 0.12 g/cm3. What is the mass of a sample of balsa wood if its volume is 134 cm3? 16 g
Density 5. The density of ice at 0 °C is 0.917 g/cm3. Calculate the volume of 145 g of ice. 158 cm3