1. Unit 5: Solutions
Honors Unit

2. A. Solutions
A solution is a mixture that is homogeneous with a solute dissolved in the solvent
Solvent a liquid that is dissolved in ( ex: water)
Solute: the solid that is dissolved in the solvent (ex: salt in water)
Rate of dissolving is affected by
Temperature
Speed
Type of Movement (mixing)

3. B. Molarity The concentration of a solution
Equation: M = mol/L mol = M*L
Unit of Molarity is M
Example: What is the Molarity if I have 3 moles of H2S in 2.5 L of solution?
*if you are given grams, convert grams  moles (divide by Molecular Weight)
*if you are given mL, convert to L (divide by 1000)

4. C. Dilutions
The process of adding water to make a solution less concentrated
Equation: M1V1 = M2V2
Example: To dilute a 13 M H2S solution to 1.0 L of a 2.0 M H2S solution, how much (volume) of the 13 M H2S solution is needed?

5. D. Dynamic Equilibrium
Le Chatelier’s Principle: if a change is imposed on a system, the position of equilibrium will shift in a direction that tends to reduce that change.
Endothermic: absorbs heat for the reaction. Example: N2 (g) + O2 (g) + 180kJ ↔ 2 NO (g) *heat is on the reactant side
Exothermic: releases heat for the reaction Example: 2 NO (g) ↔ N2 (g) + O2 (g) + 180kJ *heat is on the product side

6. D. Dynamic Equilibrium
4. Reactions move forward OR backwards depending on their conditions. 5. Equilibrium: when both directions are operating at equal rates 6. Conditions: a. number of moles (move to less moles) ex: 4 moles  3 moles to the right 

7. D. Dynamic Equilibrium
6. Conditions (continued) b. heat (uses the heat) ex. H2 (g) + Cl2 (g) ↔ 2 HCl (g) + heat to the left  ex. N2O4 (g) + heat ↔ 2 NO2 (g) to the right 
Add Heat
Remove Heat
Endothermic
Increase
Decrease
Exothermic

8. D. Dynamic Equilibrium
6. Conditions (continued) b. continued 1. Left Side = Reactants 2. Right Side = Products c. Pressure: moles of gas -move to the side with less moles of gas. *For assistance:

9. E. Dynamic Equilibrium Practice

10. E. Dynamic Equilibrium Practice

11. E. Dynamic Equilibrium Practice

12. F. Hydrate
Hydrate: a substance that contains water Example: Na2CO3 * 10 H2O
Anhydrous: (unhydrated) a hydrate substance that has lost ALL water molecules.
Example: A g sample of a hydrate of Magnesium Carbonate was heated, without decomposing the carbonate, to drive off water.
Determine the MASS of water driven off:
15.67 g – 7.58 g = 8.09 g

13. F. Hydrate
b. Determine the MOLES of MgCO3 and water MgCO3 = 7.58 g/ g/mol = mol MgCO3 H2O = 8.09g/ g/mol = mol H2O c. Find the Whole Number ratio of the compound divided by MgCO3 MgCO3 = mol/ mol = 1 H2O = mol/ mol = 5 ANSWER = MgCO3 * 5 H2O For Assistance: