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Solutions. Unit 4. Mixture. Two or more substances together Mixture of two solids Spoonful of salt mixed together with a spoonful of baking soda. Mixture of two liquids Cup of olive oil and a cub of vinegar Mixture of a solid and a liquid Sand in an aquarium full of water.
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Solutions Unit 4
Mixture • Two or more substances together • Mixture of two solids • Spoonful of salt mixed together with a spoonful of baking soda. • Mixture of two liquids • Cup of olive oil and a cub of vinegar • Mixture of a solid and a liquid • Sand in an aquarium full of water
Mixture of two solids Salt Baking Soda Salt and Baking Soda Mixture
Mixture of two solids • Simplest kind of interaction • Pieces of the two substances are randomly interspersed and they come to rest against one another • Two kinds of particles coexist and are completely unaffected by being close with one another • Two substances are still identifiably distinct
Mixture of two liquids • When mixed and shaken, the two liquids are distributed throughout one another in tiny droplets • When mixing stops, the two substances rejoin other droplets of their own kind and reassemble themselves into two individual substances • Two substances are still identifiably distinct
Mixture of a solid and a liquid • Water still a pure continuous mass, but now infused with sand chunks • When mixing stops, gravity pulls on sand to settle at the bottom • Every surface of the sand is in contact with the water • Substances still coexist independent of one another
Dissolve • To incorporate one substance uniformly into another substance at the particle level • Example • Sugar and water
Solution • A mixture formed when one substance dissolves in another • What dissolves is known as the solute • What the solute dissolves into is the solvent
Question • Between the sugar and the water, which is the solute and which is the solvent? Solute? Sugar Solvent? Water
Examples • The Air • Solvent Nitrogen gas • Solute Oxygen gas • Brass • Solvent Copper • Solute Zinc
Brass • Copper (Solvent) + Zinc (Solute) = Brass
Concentration • The amount of solute dissolved in a measure of solvent • Imagine two beakers with 100 mL of water in each. One has 5g of sugar, the other 10g of sugar
Example 5g Sugar 10 g Sugar
Questions • How are the two solutions the same? • Answer • Both contain water and sugar • Both are clear • Same amount of Water
Questions • How are the two solutions different? • Answer • Amount of solute (sugar)
Ways to express concentration • 1st – Mass Ratio • Ten grams of sugar in 90 g of water produces a 10% sugar solution • Total mass = 10g + 90g = 100g • 10g sugar divided by 100g = 10% • 2nd – Parts per thousand or Parts per million • Every liter (1000mL) of seawater contains 19 g of chlorine particles. • So there are 19 parts per thousand of chlorine in seawater
Saturation • Saturated – a solution with the maximum amount of dissolved solute • A fixed amount of water will dissolve a certain amount of sugar. • If more sugar is added, it will not dissolve, but fall to the bottom of the container.