Physical Properties of Solutions: Definition, Types, and Stoichiometry

PHYSICAL PROPERTIES OF SOLUTION  What Is a Solution? is a type of homogeneous mixture that is made up of two or more substances. A homogeneous mixture is a type of mixture with a uniform composition.  Let's make use of our salt water example to talk about the two main...

PHYSICAL PROPERTIES OF SOLUTION  What Is a Solution? is a type of homogeneous mixture that is made up of two or more substances. A homogeneous mixture is a type of mixture with a uniform composition.  Let's make use of our salt water example to talk about the two main parts of a solution. These are: Solute: this is the substance that makes up the minority of the solution, or this is the part that is dissolved. Example, the salt water, the solute is the salt. Solvent: this is the substance that makes up the majority of the solution. This is the part where the solute is dissolved. Example, the salt water, the solvent is water.  TYPES OF SOLUTIONS On the basis of physical states of solute and solvents Gaseous Solutions: gases can spontaneously mix in any proportion. Liquid Solutions: liquid solutions are the most common and they can be obtained by dissolution of a gaseous, liquid or solid solute. Solid Solutions: they are generally called alloys, where two or more metals are present. Mercury alloys are called amalgams, and they can be liquid or solid.  Gaseous Solution A smaller amount of one gas (solute) is dissolved in a larger amount of gas. (solvent) Both Solvent and solute are gases Gaseous Solute in a Liquid Solvent When a gas dissolves in a liquid, you get a gas- liquid solution. Carbonated Water (soda) Liquid Solute in a Liquid Solvent When a liquid dissolves in another liquid, you get a liquid-liquid solution. Alcohol in Water Solid Solution Substitutional Solid Solution  Mercury is a special type of alloy where mercury is one of the components amalgams  Solids forming Solution Stalactites and Stalagmites in caves are formed from solutions. Water with dissolved minerals flows through rocks at the top of the cave. This solution drips from the ceiling of the cave. When drops evaporate, the minerals are left behind. Stalactites develop downward, stalagmites upwards.  TYPES OF SOLUTIONS On the basis of dissolution of solute in solvent A saturated solution contains the maximum amount of a solute that will dissolve in a given solvent at a specific temperature. An unsaturated solution contains less solute than the solvent has the capacity to dissolve at a specific A supersaturated solution contains more solute temperature. than is present in a saturated solution at a specific temperature. Energies of Solution Formation "Like dissolves like" Step 1: Separating the solution into individual components of the solute (expanding the solute). Step 2: Overcoming intermolecular forces in the solvent to make room for the solute (expanding the solute) Step 3: Allowing the solute and solvent to interact to form the solution Enthalpy of hydration is step 1 and step 2 Energies of Solution Formation  Concentration Units  The concentration of a solution is the amount of solute present in a given quantity of solvent or solution. a.) Percent by Mass % by mass = = Percent by Volume % by volume = b.) Mole Fraction (X) = c.) Molarity (M) = d.) Molality (m) = e.) Parts per million ppm = x ppm Amount of the solute present in one million parts of the solution 1 ppm is one part by weight, or volume, of solute in 1 million parts by weight, or volume, of solution.  For Example: (Parts Per Million) Water Contamination If there is 1 mg of a chemical in 1 liter (1 kg) of water, the concentration is 1 PPM. (This means for every 1 million parts of water, there is 1 part of the chemical.) SOLUTION STOICHIOMETRY 1. 15g of NaCl was dissolved in 225g of water. What is the mass percent of NaCl in the solution? SOLUTION STOICHIOMETRY 2. 25mL of Methanol (d = 0.792 g/cm^3 is mixed with 150mL of water (d=1g/cm^3). What is the volume percent of Methanol? What is the m% of water? SOLUTION STOICHIOMETRY 3. 2 mol of KCl is dissolved in 8 moles of water. What is the mole fraction of KCl SOLUTION STOICHIOMETRY 4. 25 g of NaF is mixed with 200g of H2O? What is the mole fraction of NaF in the solution SOLUTION STOICHIOMETRY 5.) 15 g of NaBr is dissolve in 400 mL of solution. What is the molarity of the solution.