Published on February 16, 2014
Solutions IB Chemistry: Chapter 1 Section 1.5
What parts make up a solution? Solution is a mixture of two components. 1. Solute: less abundant component, the substance being dissolved 2. Solvent: more abundant component, the dissolver Solutions in water are called aqueous (aq).
Concentration As more and more solute gets dissolved, the solution becomes more concentrated. When the solvent can no longer dissolve any more solute, it is saturated. (If less solute is dissolved, unsaturated.) Solution can dissolve more solute than usual under particular circumstances – supersaturated.
Molarity Molarity is a term we use to describe concentration. = mol/dm3, Molarity = moles (n) of solute dissolved in 1 dm3 of solution. M is the molarity of 2.98g of NaCO3 in 500cm3 of solution? What
Dilutions Sometimes, we need a diluted solution for a particular procedure. In order to dilute, you add water to a more concentrated solution. The equation we use to determine how much concentrated solution we need is: M1V1=M2V2
Types of Mixtures Classified by: Size of the particles Whether they exhibit the Tyndall effect
Types of Mixtures Solution: Particles are evenly distributed and do not separate on standing No Tyndall Effect Example: food coloring and water mixture
Solution Example Notice how you cannot see a distinction between solute and solvent. It is the same throughout the solution.
Types of Mixtures Suspensions: Particles are not evenly distributed. Particles are suspended but will eventually settle into layers Exhibits Tyndall Effect Examples: Dirt and water mixture
Suspensions The larger particles in a suspension settle out over time. Particles are only physically combined.
Types of Mixtures Colloids: Particles are not evenly distributed. Particles are suspended but will eventually settle into layers Exhibits Tyndall Effect Examples: milk
Colloids Looks like a solution to the naked eye. Particles are suspended. The particle size is the “in betweener”, larger than a solutions’ particles but smaller than a suspensions’ particles.
What is this “Tyndall effect”? Light scattering by particles. Found in colloids and suspensions, but not solutions.
Hydrates Hydrates are ionic compounds that have water molecules absorbed into the crystal lattice. Hydrates are still solid, just have certain amounts of water attached to the ions. An example of a hydrate is Copper (II) Sulfate pentahydrate: CuSO4 ● 5H2O
Hydrates An example of a hydrate is: CuSO4 5H2O This means that for every 1 unit of copper sulfate, there are 5 units of water. Or, for every 1 mole of copper sulfate there are 5 moles of water. Solve for the molar mass. (The dot does not mean multiply, just add the mass of water to mass of copper sulfate.)
Properties of Solutions: Dissociation When If a solute dissolves, the solute molecule is surrounded by water molecules. the solute is ionic, than the ions separate and are surrounded by water molecules. Example: NaCl Na+ + Cl-
Model of NaCl dissolving in water Na+ ClNa+ ClNa+ Cl- Na+ Cl- Cl- Na+ Na+
Dissociation Continued Because of this, ionic substances have more of an effect on the boiling point and freezing point than a covalent bond (something that is not ionic). C6H12O6 (s) C6H12O6 (aq) NaCl(s) Na+ (aq) + Cl-(aq) CaCl2 (s) Ca2+ (aq) + 2Cl-(aq) (1 particle being dissolved, not ionic) (2 particles being dissolved, ionic) (3 particles being dissolved, ionic) CaCl2 will have the largest effect (higher melting/boiling pts) and glucose the least effect (lower melting/boiling pts).
Ability to Conduct Electricity If ions are present in solution, it will conduct eletricity……all ionic substances will conduct electricity when dissolved. Ex: Tap water, salt water Solutes that conduct electricity when dissolved are called electrolytes.
Electrolytes Importance of electrolytes: The movement of calcium ions allows muscles to contract and relax Presence of sodium and potassium ions allow your nerve cells to respond to stimuli.
STRONG vs. weak Electrolytes Strength depends on number of ions in solution More ions = stronger electrolyte, Fewer ions = weaker electrolyte For strong electrolytes, increasing concentration increases conductivity Weak electrolytes, increasing concentration does not effect conductivity
Think about it!!! For strong electrolytes, increasing concentration increases conductivity Weak electrolytes, increasing concentration does not effect conductivity WHY????
Colligative Properties 1. Boiling point of the solvent elevates 2. Freezing point is lowered Vapor pressure is lowered, fewer molecules of solvent are escaping to the gas phase when a solute is present. The solvent molecules cannot escape because they are “busy” keeping the solute dissolved.
Salting the Roads! Rock salt (CaCl2) is used to keep the roads from freezing in the winter. Ever wonder why that happens????
1 BIOCHEMISTRY I (CHMI 2227 E) PROBLEMS and SOLUTIONS Eric R. Gauthier, Ph.D. Department of Chemistry and Biochemistry January 2007
Biochemistry, Solutions Manual [Donald Voet, Judith G. Voet] on Amazon.com. *FREE* shipping on qualifying offers. Biochemistry 3rd edition DONALD VOET ...
Marcy Osgood - Lehninger Principles of Biochemistry Study Guide and Solutions Manual: The Absolute jetzt kaufen. ISBN: 9781429212410, Fremdsprachige ...
Get instant access to our step-by-step Biochemistry solutions manual. Our solution manuals are written by Chegg experts so you can be assured of the ...
Access Biochemistry 7th Edition solutions now. Our solutions are written by Chegg experts so you can be assured of the highest quality!
Lehninger Principles Of Biochemistry 5th Edition Solutions Manual. 7,031 likes · 3 talking about this. Lehninger principles of biochemistry 5th edition...
Find great deals on eBay for biochemistry solutions . Shop with confidence.
Biochemistry 3rd edition DONALD VOET, University of Pennsylvania, USA and JUDITH G. VOET, Swarthmore College, USA Biochemistry is a modern classic that has ...
Biochemistry All Publications/Website x. Select a CAS section from the 5 main topical divisions ... Phase Equilibriums, Chemical Equilibriums, and Solutions;