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Solutions

Solutions. What is a Solution. A solution is a homogeneous mixture. What a solutions made of. Solutions consist of two parts a solute and a solvent The solute is the material that is being dissolved The solvent is the material that the solute is being dissolved into Solubility

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Solutions

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  1. Solutions

  2. What is a Solution • A solution is a homogeneous mixture

  3. What a solutions made of • Solutions consist of two parts a solute and a solvent • The solute is the material that is being dissolved • The solvent is the material that the solute is being dissolved into • Solubility • Solubility is the property of a solid, liquid, or gaseous chemical substance  called  solute to dissolve in a solid, liquid, or gaseous solvent to form a homogeneous solution of the solute in the solvent. 

  4. How do chemicals become Solutions

  5. How do we Measure Solubility • The solubility of a solute in a solvent at a particular temperature is the number ofgrams of the solute necessary to saturate 100gm of the solvent at that temperature

  6. What factors affect solubility • There are four factors that have an effect on solubility • Temperature • Nature of solute or solvent • Pressure • Particle size

  7. Temperature • With solids and liquids solubility increases as temperature increases because particles are hitting each other more often • With gasses solubility decreases as temperature increases because the higher kinetic energy of the materials causes the particles to escape into the atmosphere

  8. Solubilities of Solids vs Temperature

  9. Temperature & the Solubility of GasesThe solubility of gases DECREASES at higher temperatures

  10. Nature of solvent and solute • The key phrase to remember here is “Like Dissolves Like” • Polar solvent dissolves polar solutes • Non-polar solvent dissolves non-polar solutes

  11. Pressure • With liquids and solids pressure has very little to do with solubility because the particles are already close together • With gasses the higher the pressure the higher the solubility because you are putting more particles in a closer proximity to one another

  12. Particle size • Particle size does not affect the amount of a solute that will go into solution but it does affect the speed at which something goes into solution. • The smaller the particle size the faster it goes into solution because it has increase surface area and thus more material open to react

  13. Concentration •  The amount of a substance per defined space. Concentration usually is expressed in terms of mass per unitvolume • The are 4 way to express concentration of a solution • Molarity(M) • Molality (m) • Mass percent • Mole Fraction

  14. Molarity(M) • Molarity is the number of moles of solute dissolved in one liter of solution. The units, therefore are moles per liter, specifically it's moles of solute per liter of solution. • molarity = moles of solute  liter of solution

  15. Molality (m) •  the molality,  m of a solvent/solute combination is defined as the amount of solute in molesnsolute, divided by the mass of the solvent, msolvent (not the mass of the solution)

  16. Mass Percent • The mass percent is a calculation of the amount of what part of the mass of the solution comes the solute • (mass solute / mass of solution) * 100

  17. Mole Fraction • Mole Fraction is a comparison of the number of moles of a solute in a solution to the total number of moles of solution • moles solute / total moles solution

  18. Suppose you have 0.500 M sucrose stock solution. How do you prepare 250 mL of 0.348 M sucrose solution ? Concentration 0.500 M Sucrose 250 mL of 0.348 M sucrose Dilution When a solution is diluted, solvent is added to lower its concentration. The amount of solute remains constant before and after the dilution: moles BEFORE = moles AFTER C1V1 = C2V2 A bottle of 0.500 M standard sucrose stock solution is in the lab. Give precise instructions to your assistant on how to use the stock solution to prepare 250.0 mL of a 0.348 M sucrose solution.

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