Presentation on theme: "Day 1 – Types of Solutions & Water and its Properties."— Presentation transcript:
Day 1 – Types of Solutions & Water and its Properties
Mixtures! Mixture: physical blend of two or more substances (no rxn, just dumped) Homogeneous mixture: uniform composition (i) also called a solution (ii) its components are NOT readily distinguished Examples: Coca-Cola, HCl (aq), salt water
Heterogeneous mixture: not uniform in composition (can pick them apart easily) its components are readily distinguished (which means you CAN see them!). Examples: trail mix, sand, this class!
Types of Mixtures: Solutions A solution is a homogeneous mixture of two or more substances in a single phase Solute – substance being dissolved (least amount) Solvent – medium DOING the dissolving (greater amount)
In a solution, the solvent and the solute do not need to be in the same phase. Any phase of matter can dissolve in any other phase of matter.
Water Molecule botimages.html
Universal Solvent Because of its polar nature, water can easily dissolve many substances and is commonly known as the “Universal Solvent”
The Solution Process Water molecules are in continuous motion. When a solute is added the water molecules will collide with it. The polar nature of water molecules attract the solute particles and the particles will break away.
Negative side of water molecules will surround positive cations The Solution Process
Positive side of water molecules will surround negative anions The Solution Process
Dissolving polar molecular compounds
Density – ice floats in water! One of the few solids in which a solid will float in its own liquid. Hydrogen bonding causes water molecules to arrange in a honeycomb pattern which increases the volume of the ice and makes it less dense
If the solute does dissolve in the solvent, the solute is soluble. (aq) If it doesn’t dissolve it is insoluble. (s) Forms a precipitate
Solubility Rules Use STAAR chart to determine whether or not a compound is soluble (aq) or insoluble (s) Cu(NO 3 ) 2 MgCO3 NH4Cl NaOH Mg(OH)2 PbCrO4
Solubility Rules Use STAAR chart to determine whether or not a compound is soluble (aq) or insoluble (s) Na2CrO4 MgCrO4 CuCl2 MgF2 CuSO4 Hg2SO4
Predicting Products in a Double Replacement Reaction Na2SO4 + BaCl2 2 Cr(NO3)3 + 3 (NH4)2S BaSO4 + 2NaCl 6(NH4)NO3 + Cr2S3 (s) (aq) (aq) (s) 3 KNO3 + FeCl3 Fe(NO3)3 + 3 KCl (aq) (aq) Since all reactants and products are soluble (aqueous), technically nothing happened. (No Reaction)