Unit 8 Chemistry Review

Lesson 1 - Types of mixtures 

• Suspensions 

  • Mixtures where particles are large

  • Particles will settle down at the bottom if not mixed

  • Heterogeneous: not evenly dispersed 

  • Can scatter light, but is not transparent 

• Colloids 

  • Mixtures where particles are intermediate in size 

  • Also called colloidal dispersion 

  • Dispersed phase 

    • This means that the solvent is dispersed in the dispersion medium or the solvent, in the form of colloidal particles

    • 

  • Tyndal effect 

    • is the scattering of light by colloidal particles dispersed in a transparent medium

    • Ex: fog 

  • Heterogeneous: not evenly dispersed 

  • Particles do not separate 

  • Cannot be separated through filtration 

• Solutions 

  • Soluble: capable of dissolving 

  • Homogeneous: evenly dispersed 

  • Solvent: thing dissolving the solute 

  • Solute: substance being dissolved 

  • Example 

    • Metal alloy 

      • Homogeneous solution 

  • Particles do not separate 

  • Cannot be separated through filtration 

  • Do not scatter light 

• Electrolytes 

  • A substance that dissolves into water to give an electric current 

  • Ionic solutions 

Lesson 2: the solution process 

• Miscible 

  • Liquids that can be dissolved into each other 

• Immiscible 

  • Liquids that do not dissolve into each other 

• Hydration 

  • A solution with water as the solvent 

  • When LiCl is dissolved in water, the ions are hydrated. The attraction between ions and water molecules is strong enough that each ion in solution is surrounded by water molecules 

  • Dissolving ionic compounds in aqueous solutions 

    • Li⁺ (aq); Cl^- (aq) – aq (aqueous)

• Factors affecting dissolving 

  • Increased surface area of the solution

  • Stirring of a solution 

    • Stirring speeds up the process of dissolving because a new solvent comes in contact with the solute quicker 

  • Heating a solvent 

    • Heating increases the rate at which the particles in the mixture move, making the particles bump into each other more often, and come more income with each other on the surface

• Types of saturation 

  • Unsaturated solution 

    • More solute can be dissolved into the solvent 

  • Saturated solution 

    • No more solute can be dissolved into the solvent 

  • Supersaturated solution 

    • More solute is dissolved in a mixture than in the saturated solution under the same conditions 

• Solution equilibrium 

  • A point of dissolving where the solution is at max saturation, and there is a set concentration of crystalized and saturation solution. The rate at which the crystals resolve or undergo dissolution and the rate at which the solute recrystallizes are the same so that the concentration of crystalized and saturation solution remains constant. 

• Solubility 

  • The maximum amount of solute that can be dissolved in a solute in consideration of amount/quantity and temperature 

Lesson 3: concentration of solutions 

• Dilute 

  • Contains a small amount of solute 

• Concentrated 

  • Contains a large amount of solute 

• Concentration 

  • Measure of amount of solute in a given solvent 

  • Percent volume 

    • % volume = (volume solute/ volume solution) x 100 

  • Percent mass 

    • % mass = (mass solute/ mass solution) x 100 

  • Solution = solute + solvent 

• Molarity 

  • The number of moles of solute in 1 liter of solution 

  • Molarity = ( solvent in moles/liters of solution ) 

  • Molarity is the most common unit of concentration 

• Preparations from solutions to stock solutions 

  • Formula: M₁V₁ = M₂V₂

    • M₁ – Initial Molarity

    • V₁ – Initial Volume 

    • M₂ – New Molarity

    • V₂ – New Volume

Lesson 4: properties of acids and bases

• Acids 

  • Aqueous (water as solvent) solutions of acids have a sour taste 

  • Acids change the color of acid-based indicators 

  • Some acids react with active metals and release hydrogen gas, H2

    • People take acid to a heavy metal concert, and get hot hot 

  • Acids react with bases in a neutralized reaction to produce salts and water 

    • HCl  +   NaOH  →   NaCl  +  H₂O

  • Acids conduct an electrical current (electrolytes) 

  • pH less than 7 

  • Binary acid

    • Hydrogen and one of the more electronegative elements 

      • Hydrofluoric acid (HCl)

    • Bi meaning two

  • Ternary acid 

    • Compound with hydrogen, oxygen, and a third element 

      • Chloric acid ( HClO₃) 

    • Tern like three (hydrogen, oxygen, and another)

• Bases 

  • Aqueous solutions of bases have a biter taste 

  • Bases change the color of acid-base indicators 

  • Dilute aqueous solutions of bases feel slippery 

  • Bases react with water to produce salt and water 

  • Bases conduct electric current 

  • Ph greater than 7

Lesson 5: Acid-base theories and reactions 

• Arrheneous acid 

  • A chemical compound that increases the concentration of hydrogen ions (H⁺/H₃O⁺) in an aqueous solution (water as solvent)

  • 

    • Hydrogen is positively charged, so the H in HNO3 moves to the H20 to create H30 and is positively charged instead of neutral

  • The acid has H+ in the H20 

  • Arr - hen ---> add hydroHEN

• Arrhenius base 

  • A chemical reaction that increases the concentration of hydroxide ions (OH^-) in an aqueous solution 

  • 

• Strong vs weak acids 

  • Strong 

    • Ionizes completely in an aqueous solution 

    • Every ion in the solute completely breaks down in the solvent (water) and there are no more ions still undissociated 

    • 

    • Does not go back and forth: strong and stable 

  • Weak 

    • Not all of the acid is dissociated 

    • Some of the ions are still connected 

    • 

    • Goes back and forth: weak not stable 

• Bronsed-Lowry acid 

  • Molecule or ion that is the proton donor (H+)

  • H+ donor 

  • Bronsed-Lowry sounds like an agreement or transaction. The acid and base are initiating a transaction where the acid donates a proton (H+) to the base, which accepts it. It is a transaction 

• Bronsed-Lowry base

  • Molecule or ion that is the proton acceptror (H+)

  • H+ acceptor

• 

  • Acids are coverted to its conjugate base. Base is converted into its conjugate acid. 

    • First idenfity OG acid or base (H->acid, OH->base)

    • The other one is the oposite 

    • Find the similar molecule and name it the conjugate of its opposite (ei: if its base the similar lookin one is conjugate acid) 

    • Follow these steps for the remaining components 

• Bronsed-Lowry acid-base reaction

  • Protons (H+) are transferred from the reactant (acid) to another (base)

• Atmospheric substances 

  • Can be both acids and bases

  • Ex: H20

• pH -> potential hydrogen power

  • The negative of the common logarithm of the hydronium ion concentration [H₃O⁺] or [H⁺]

  • pH = -log [H30+]

• pOH -> 

  • The negative common logarith of the hydroxide ion concentration [OH-]

  • pOH = -log [oh-]

• pH + pOH = 14