Study Guide: Chapter 16, 17 & 18

Study Guide: Chapter 16, 17 & 18 Name: Water, Solutions & Equilibrium

Chapter 16 WATER

Water is a ______molecule with 2 forces.  Intra-molecular – strong ______bond that makes up the water ______.  Inter-molecular – weak ______between different water molecules. There are 3 different Inter-molecular forces. 1. ______2. ______3. *______* A ______so strong it’s given a special name.

**Refer to Ch 15 study guide for complete explanation of all 3 inter-molecular forces.

______is very important in determining the properties of water.

Hydrogen bonding is responsible for many of the unique properties of Water: 1. ______4. ______

2. ______5. ______

3. ______

1. Surface Tension: The surface of water acts like a ______. Water does not ______to air but does to other molecules ______. This pulls the molecules ______the body of the liquid.

This ______force or pull Diagram: tends to ______the surface area of any liquid is called ______.  A ______is the smallest ______for a given volume.  ______tends to flatten it out.  The ______the ______the ______the surface tension and more ______the drop.  All liquids have ______some more than others. Water’s is ______.

Surfactants: ______interfere with ______and flatten out the molecules instead of rounding. Another name; ______.

2. Low Vapor pressure: Vapor pressure is the pressure exerted by the ______phase of a liquid in a ______. The Lower the vapor pressure the ______the liquid will evaporate. Contrary to water, gasoline has a ______vapor pressure and evaporates ______. This is because water has the ______inter-molecular force of ______and gasoline does not.

3. High Heat Capacity: (Ch. 10 Thermo-chemistry) Review, get your note packet to help you do the problem sheet for homework.  Heat capacity is the amount of ______( ) required to change the temperature of a substance by ______.  Specific heat capacity is the amount of ______( ) required to change the temperature of 1gram of a substance ______.  Water has a ______specific heat. ( ) Water exists at temperatures from ______. Ice exists at temperatures ______and Steam exists at temperatures ______both have a specific heat value of ______.

Why do People in Atlantic City have warmer winters and cooler summers compared to those in Philadelphia even though they are about the same latitude?

Use the same reasoning to explain why our temperatures do not fluctuate daily (morning to night) as drastically as the temperature fluctuates in the desert. ** You are responsible for knowing the energy changes of water: Phase changes and temperature changes and energy changes and must be able to define the following terms and solve problems relating to energy and water. (Use the chapter 10 study guide) HOMEWORK

Heat of fusion:

Heat of vaporization:

Energy required to change the state of water (phase change): q = m(heat of fusion) or q = m(heat of vaporization) heat of fusion of water = 80cal/g heat of vaporization of water = 540cal/g

Energy required to change the temperature of water:

q = mC∆T C = specific heat ∆T = Tfinal - Tinitial Cwater = 1 cal/gºC

HOMEWORK: Energy problems worksheet (use Ch. 10 study guide)

4. High Heat of Vaporization: (See notes above from Ch. 10) It takes a lot of energy to change water from a ______at 100ºC to a ______at 100ºC.

5. High Boiling Point: The molecular weight of water is ______, which is low but has a ______boiling point for its molecular weight! Most compounds with low molecular weights also have ______.

Example: Methane CH4 Molecular Weight = ______& Boiling Point = ______Water H2O Molecular Weight = ______& Boiling Point = ______

Water is Weird!!! Water is the only known liquid to ______when it forms a solid. Ice is ______than water so it floats.

Density Changes of Water Diagram: **(Water is the most dense at ______) Solutions Activity (Part A)

Solution:

Solvent:

Solute:

Aqueous solution:

Solvents & Solutes may be solids, liquids or gases. Examples: Solids:

Liquids:

Gases:

(Part B)

General rule for what substances dissolve what substances:

Why doesn’t oil and water mix?

How come some ionic solutions will not dissolve?

How do non-polar compounds form solutions? (Part C) The process for something dissolving is called SOLVATION.

Solvation:

Diagram showing solvation process (3 steps) and word explanation:

(Part D) Electrolyte:

What compounds are always electrolytes and why?

What type of compounds are non-electrolytes? (define and explain)

(Part E) Strong electrolyte:

(2 examples):

Weak electrolyte:

(2 examples):

Non-electrolye:

(2 examples) Water of Hydration (Chapter 6 chemical quantities Review)

HYDRATED SALT (HYDRATE) –

WATER OF HYDRATION –

How many formula units to how many water molecules? ( . does not mean multiplication) . Epsom Salt MgSO4 7H2O . Calcium chloride CaCl2 2H2O

How and why can the water be removed easily and rehydrated easily?

Define the following terms:

Anhydrous salt

Hygroscopic (dessicants – small packets of silica gel found in pocketbooks and shoes)

Deliquescence

Efflourescnce

**All hydrates are salts, but not all salts are hydrates!! Hydrate Problems: Finding the % water in a hydrate

% = (part / whole) x 100 or gfm water in hydrated salt gfm salt + water

. Calculate % H2O in MgSO4 7H2O . Calculate %H2O in CaCl2 2H2O

Quiz on water chapter: definition fill-in and multiple choice

Chapter 17: Solutions There are 3 main types of solutions: 1. gaseous solutions – 2. liquid solutions – 3. solid solutions –

Factors affecting dissolving rates: 1. Surface area –

2. Agitation –

3. Heating solvent –

SOLUBILITY –

How does a solute dissolve in a solvent? ______3 step process (mechanisms): 1.

2. 3A.

Solution Equilibrium –

**Le Chatlier’s Principle: (physical or chemical change)

A SATURATED SOLUTION IS IN EQUILIBRIUM: 

Unsaturated Solution:

Supersaturated Solution:

Factors affecting solubility: 1. Types of solvents and solutes –

Immiscible-

Miscible- 2. Pressure –

(*Le Chatlier Principle) –

(Effervescence)-

3. Temperature – (Gases)

(Solids in liquids)

Heats of Solution (solubility activity) Heat of solution-

SOLVATION CAN BE THOUGHT OF IN 3 STEPS (mechanisms): 1. solute-solute:

2. solvent-solvent:

3. solute-solvent: *Heat of solution is positive (heat absorbed/endothermic) –

*Heat of solution is negative (heat released/exothermic) –

SOLUBILITY CURVE GRAPH

*If the graph curves up then grams of solute ___ when temp __ (______) as temp increases solubility increases

*If the graph curves down then grams of solute ___ when temp ___ (______) as temp increases solubility decreases *Dissolving gases always exothermic DO SOLUBILITY WORKSHEET

HOW TO EXPRESS THE CONCENTRATION OF A SOLUTION:

Concentration:

Dilute solution:

Concentrated solution: Molarity: ( )

A: Calculating Molarity:

B: Finding grams of solute in a solution of known Molarity:

C: Calculating (GFM) molecular weight of solute:

D: Making dilutions:

Homework: Molarity problems

Quiz on Chapter 17: Matching definitions, short answer and problems CHAPTER 18: RXN. RATES & EQUILIBRIUM

Reaction rate:

Collision Theory:

(Activation Energy)

4 factors affecting reaction rates 1. Temperature 3. Particle Size 2. Concentration 4. Catalyst (Read pages 396 -399 and fill in information below for your assigned factor. You must explain how it affects reaction rate and how it’s related to the collision theory.)

Temperature Increase –

Decrease-

Concentration-

(example)

Particle size –

Catalyst – Reversible Reaction

LeftRight

RightLeft

Mechanisms of a reversible reaction 1

** The rates of both the forward and reverse reaction are the same. This does not mean that the concentration of the components on both sides of the equation are the same!!

Le Chatlier’s Principle-

Factors affecting Equilibrium

1. change in concentration of reactants 3. change in temperature 2. change in concentration of products 4. change in pressure (using page 415 in text book explain the affect on equilibrium for your assigned factor)

Change in conc. of reactants

*Add reactants-

*Remove reactants – Change in conc. of products

*add product

*take away product

Change in temperature

Endothermic reaction

Exothermic reaction

Change in pressure

Gases only and the number of moles on each side of the equation must be different

{Example: ___N2(g) + ___H2(g)  ___NH3(g)} 

{Example: ___PCl5(g)  ___PCl3(g) + ___ Cl2(g) 

Example: ___C(s) + ___H2O(g)  ___CO(g) + ___ H2(g) 