Section 3.3 Mixtures of Matter Contrast mixtures and substances. Classify mixtures as homogeneous or heterogeneous. List and describe several techniques used to separate mixtures. substance: a form of matter that has a uniform and unchanging composition; also known as a pure substance Section 3-3

Section 3.3 Mixtures of Matter (cont.) heterogeneous mixture homogeneous mixture solution filtration distillation crystallization sublimation chromatography Most everyday matter occurs as mixtures—combinations of two or more substances. Section 3-3

Homogeneous mixtures are also called solutions. Examples… A mixture is a physical combination of two or more pure substances in which each pure substance retains its individual chemical properties. A homogenous mixture is a mixture where the composition is constant throughout. Homogeneous mixtures are also called solutions. Examples… Section 3-3

Solution homogeneous very small particles no Tyndall effect particles don’t settle EX: rubbing alcohol Tyndall Effect: The scattering of light by particles. C. Mixtures

Mixtures (cont.) Section 3-3

mixture is not uniform in composition Examples… Mixtures (cont.) A heterogeneous mixture is a mixture where the individual substances remain distinct. mixture is not uniform in composition Examples… Section 3-3

Colloid heterogeneous medium-sized particles Tyndall effect particles don’t settle EX: milk C. Mixtures

Suspension heterogeneous large particles Tyndall effect particles settle EX: fresh-squeezed lemonade C. Mixtures

Examples: colloid mayonnaise suspension muddy water fog solution saltwater Italian salad dressing C. Mixtures

Separating Mixtures Filtration is a technique that uses a porous barrier to separate a solid from a liquid in a heterogeneous mixture. Distillation is a separation technique for homogeneous mixtures that is based on the differences in boiling points of substances. Crystallization is a separation technique for homogenous mixtures that results in the formation of pure solid particles from a solution containing the dissolved substance. Section 3-3

Separating Mixtures (cont.) Sublimation is the process of a solid changing directly to a gas, which can be used to separate mixtures of solids when one sublimates and the other does not. Chromatography is a technique that separates the components of a mixture on the basis of tendency of each to travel across the surface of another material. Section 3-3

A B C D Section 3.3 Assessment Which is NOT a technique for separating a homogenous mixture? A. crystallization B. distillation C. filtration D. chromatography A B C D Section 3-3

A B C D Section 3.3 Assessment Which of the following is a heterogeneous mixture? A. seawater B. silver mercury amalgam C. atmosphere D. salad dressing A B C D Section 3-3