PRINCIPLES OF EARTH AND PHYSICAL SCIENCE RAINIER JR/SR HIGH SCHOOL MR. TAYLOR MIXTURES AND SOLUTIONS

MIXTURES A mixture is a conglomeration of pure substances that varies in the concentration of each substance. Mixtures can vary in the “stuff” that they are made of and can vary in the amount of each thing in them Mixtures can be separated by physical means.

MIXTURES Heterogeneous mixtures are not of consistent makeup all through them. Fruit salad, granite, Skittles and M&M’s. Suspensions are heterogeneous mixtures that have particles that settle out or can be filtered out of the mixture. The particles are usually larger than a pencil tip.

MIXTURES Heterogeneous mixtures are not of consistent makeup all through them. Fruit salad, granite, Skittles and M&M’s. Colloids are mixtures where the particles are so small they don’t settle out. They are kept mixed by collisions with other particles. Fog, whipped cream, and marshmallows

MIXTURES Heterogeneous mixtures are not of consistent makeup all through them. Fruit salad, granite, Skittles and M&M’s. An emulsion is a mixture where some agent is present that allows two substances that usually don’t mix to mix together Mayonnaise, bile salts

SOLUTIONS Homogeneous mixtures have substances that are evenly distributed and appear the same throughout the mixture. The substances can still be separated by physical means. Solutions are homogeneous mixtures where the particles are so small they don’t settle out and evenly mix through the solution Solvent: the substance of greater amount. It does the dissolving Solute: the substance of lesser amount. It is dissolved

SOLUTIONS Solvation is the process of dissolving a solute in a solvent. The solvent particles collide with the solute particles or molecules and dislodge them from each other The solvent particles then attract the solute molecules and move them by diffusion until they are evenly distributed in the solvent

SOLUTIONS Solvation is the process of dissolving a solute in a solvent. Since collisions cause the solute to go into solution, the process can be sped up by: 1.Increasing surface area of the solute 2.Stirring or shaking the solvent 3.Heating the solvent 4.Increasing the amount of the solvent

SOLUTIONS Non-liquid solutions are known; Alloys are solutions of two metals Brass: copper and zinc Steel; Iron, nickel, and other metals Bronze; copper and tin The atmosphere is a solution of many gases including nitrogen, oxygen, argon, carbon dioxide, and others.

“LIKE DISSOLVES LIKE” Polar vs non-polar substances Due to unequal sharing of electrons or the presence of ions, some substances have a charged surface. These are polar substances. Water, table salt, baking powder If there are no charged surfaces, it is a non-polar substance. Vegetable oil, wax, creams

“LIKE DISSOLVES LIKE” Polar substances will dissolve other polar substances. Non-polar substances will dissolve other non-polar substances. Polar substances WILL NOT dissolve non-polar substances, and vice versa.

WATER: THE UNIVERSAL SOLVENT Water is often called the universal solvent because many substances are dissolved in water. There are many ionic compounds and they are polar. There are many polar covalent compounds

SOLUBILITY Solubility is the ability of a solute to be dissolved in a measured volume of a solvent under normal conditions. Concentration is the actual amount of solute dissolved in a measured amount of a solvent. A saturated solution is holding the maximum amount of solute possible. An unsaturated solution can hold more solute before becoming saturated. A supersaturated solution has been manipulated to hold more solute than usually possible.

SPECIAL PROPERTIES OF MIXTURES Alloys (metal mixtures) have different properties than the metals do separately. Stainless steel resists rusting better than plain iron Aluminum alloys resist heat and friction better than plain aluminum and can be used as motor blocks. Adding solutes to solvents usually decreases the freezing point and increases the boiling point of the solvent. Antifreeze (ethylene glycol) for use in cars.

QUESTIONS ON MIXTURES?