Lundie Chemistry: February 2012

Print out your Week-of for Feb 27-Mar 2 and bring to class. I won't be there on Monday, but I've attached some URL's for YouTube if you need more explanation.
Have a nice day!

Honors Chemistry Feb 27-Mar 2 Agenda

HONORS CHEM: Week of Feb 27- Mar 2, 2012 Name_______________________________

Tentative Schedule www.lundiechem.blogspot.com Date_____________________Pd_________

Write the Question and the Answer to all ELO problems. Show all math work

MON: Notes: 15.3 Factors Affecting the Rate of Dissolution 15.4 Solution Composition:

http://www.youtube.com/watch?v=qUbYB2KtJzo

Teacher Examples: p 474 Self-Ö Ex 15.1; p 476 Self-Ö 15.2

Classwork: p. 499 #12ac, 13ac, 15, 17 Answer for 17 is 4.8 g heptane; 2.7 g pentane

ELO: p. 499 #12bd, 13bd, 14, 16

TUES: Notes: 15.5 Solution Composition

http://www.youtube.com/watch?v=JwV3F708ZrI

Guided Practice: p 478 Self-Ö Ex. 15.3; p 481 Self-Ö Ex. 15.6

Classwork: p. 500 #21a, 22a, 24, 28

ELO: p. 500 #21bd, 22bd, 23, 27bd

WED: Notes: 15.6 Dilution

http://www.youtube.com/watch?v=KM2uzc8msas&feature=fvsr

Guided Practice: p. 485 Self-Ö Ex 15.7; p. 500 #31b d, 34

ELO: p. 500 #31a c, 33

THUR: Notes: 15.8 Neutralization Reactions; 15.10 Properties of Solutions

Guided Practice: p. 490 Self -Ö Ex. 15.9; p. 500 #39, 41 b d

ELO: p.501 #40, 41 a c, 49, 50, 51

FRI: Class work: Ch 15 Test Review

ELO: Study for Test

SAVE THIS TO ATTACH TO YOUR HOMEWORK ON FRIDAY

Regular Chemistry Feb 27-Mar 2 Agenda

CHEMISTRY: Week of Feb 27- Mar 2, 2012 Name_______________________________

Tentative Schedule www.lundiechem.blogspot.com Date_____________________Pd_________Write the Question and the Answer to all ELO problems. Show all math work

MON: Notes: 15.1 Solubility, 15.2 Solution composition and PPM

ELO: p.473, Focus Questions #1,2,3; p. 499 #3

TUES: Notes: 15.3 Factors Affecting the Rate of Dissolution 15.4 Solution Composition:

http://www.youtube.com/watch?v=qUbYB2KtJzo

Teacher Examples: p 474 Self-Ö Ex 15.1; p 476 Self-Ö 15.2

Classwork: p. 499 #12ac, 13ac, 15, 17 Answer for 17 is 4.8 g heptane; 2.7 g pentane

ELO: p. 499 #12bd, 13bd, 14, 16

WED: Notes: 15.5 Solution Composition

http://www.youtube.com/watch?v=JwV3F708ZrI

Guided Practice: p 478 Self-Ö Ex. 15.3; p 481 Self-Ö Ex. 15.6

Classwork: p. 500 #21a, 22a, 24, 28

ELO: p. 500 #21bd, 22bd, 23, 27bd

THUR: Notes: 15.6 Dilution

http://www.youtube.com/watch?v=KM2uzc8msas&feature=fvsr

Guided Practice: p. 485 Self-Ö Ex 15.7; p. 500 #31b d, 34

ELO: p. 500 #31a c, 33

FRI: Notes: 15.8 Neutralization Reactions; 15.10 Properties of Solutions

Guided Practice: p. 490 Self -Ö Ex. 15.9; p. 500 #39, 41 b d

ELO: p.501 #40, 41 a c, 49, 50, 51

SAVE THIS TO ATTACH TO YOUR HOMEWORK ON FRIDAY

Wednesday, February 22, 2012

Ch 14 Test Review Questions #14-18

14. What types of intermolecular forces are acting on the liquid state of each of the following substances, and why?

a. N₂London Dispersion Forces Nonpolar Molecule

b. NH₃ H-Bonding polar/H with FON

c. He London Dispersion Forces Noble Gas/single atom

d. CO₂ LDF Nonpolar Molecule

15. List the type of crystalline solid formed by each of the following substances, and list the intermolecular or intramolecular force that forms the solid.

a. NH₄NO₃ ionic crystal no intermolecular to speak of

b. CO₂molecule London Dispersion Force

c. iron atomic/metallic no intermolecular to speak of

d. cesium fluoride ionic no intermolecular to speak of

16. What is the relationship between vapor pressure and boiling point?

When the vapor pressure is equal to the atmospheric pressure, that temperature will be the boiling point

17. What are 3 things that affect vapor pressure and boiling point?

type of intermolecular force, temperature and atmospheric pressure

18. Draw a heating and cooling curve for each of the following examples and list only the steps to get the total energy. Use the Standards Reference Sheet. (Heating curve is on next page)

a. Calculate the energy required to melt 8.5 g of ice at 0°C.

Only one step Q=m

b. Calculate the energy required to heat 25 g of liquid water from 25°C to 100°C and

change it to steam at 100°C.

1st step: Q=c_pmΔT

2nd step: Q=mΔH_vap

Add up answers

c. Calculate the total energy required to melt 15 g of ice at 0°C, heat the water to 100°C,

and vaporize it to steam at 100°C.

1^st step: Q=mΔH_fus

2nd step: Q=c_pmΔT

3rd step: Q=m

Add up the answers

Ch 14 Test Review Questions #9-13

9. Why does the process of vaporization require an input of energy?

The intermolecular forces that hold the molecules together in the liquid state must be overcome.

10. Explain how the process of vaporization and condensation represent equilibrium in

a closed container. Use a sketch to emphasize your point.

First the liquid phase begins to evaporate into the empty space. When the air space above the liquid becomes saturated with gas molecules, the gas molecules re-enter the liquid phase. There is constant movement between the liquid/gas phase.

11. How is the boiling point of a liquid related to the atmospheric pressure.

A liquid boils when its vapor pressure is equal to atmospheric pressure. As the temperature increases, the particles of the liquid are more likely to have enough energy to escape the liquid. However, this amount of energy is dependent on the pressure around the liquid. Thus, as the atmospheric pressure decreases, less energy is required and the boiling point of the liquid decreases.

12. Describe in detail 3 important types of crystalline solids and give an example of each.

Ionic - alternating positive Na⁺ and negative Cl^- ions. Each positive ion is surrounded by several negative ions, and each negative ion is surrounded by several positive ions. The electrostatic forces that develop in such an arrangement are very large, the resulting substance is very stable, and has high melting and boiling points.

Ice is a molecular solid. The crystals consist of polar water molecules arranged in three dimensions so as to maximize dipole-dipole interactions (hydrogen bonding). Figure 14.18c shows a representation of an ice crystal, showing how the negative end of one water molecule is oriented towards the positive end of another water molecule, and how this arrangement repeats. Since dipole-dipole forces are weaker than ionic bonding forces, substances that exist as molecular solids typically have much lower melting and boiling points.

Atomic solids vary as to how the atoms are held together in the crystal. Substances such as the noble gases are held together in the solid only by very weak London dispersion forces. Such substances have extremely low melting and boiling points because these forces are so weak. In other atomic solids, such as the diamond form of carbon, adjacent atoms may actually form covalent bonds with each other, causing the entire crystal to be one giant molecule. Such atomic solids have much higher boiling and melting points than those substances held together by only London forces. Finally, the metallic substances are also atomic solids, in which there are strong, but nondirectional, bonding leading to the properties associated with metals. Metals are envisioned in terms of the "electron" sea model in which a regular array of metal atoms exist in a "sea" of freely moving valence electrons.

13. List 3 alloys and the metals from which they are made.

sterling silver - silver and copper

brass - copper and zinc

steel - iron and carbon

Ch 14 Test Review Answers 1-5 2005-6

1. What is meant by the latent heat of fusion.

the amount of heat required to melt 1 gram of a substance

2. What is meant by the latent heat of vaporization.

the amount of heat required to vaporize or change 1 gram of a liquid to a gas

3. Are changes in state physical or chemical changes? Explain.

Physical changes: No chemical bonds are broken during the change and no new substances result (no changes in the intramolecular forces take place).

4. Which is larger, the latent heat of vaporization of water or its latent heat of fusion? Explain.

The molar heat of vaporization is larger because in order to form a vapor, the molecules have to be moved much farther apart, all the intermolecular forces must be overcome.

5. Why does the boiling point of a liquid vary with altitude?

Because the atmospheric pressure (against which the vapor must be expanded during boiling) decreases with altitude.

6. Order the intermolecular and intramolecular forces according to strength (strongest first).

Network solid, Ionic, metallic, covalent, hydrogen bonding, dipole-dipole, London Dispersion Forces

7. Sketch the H-bonding of NH₃, What other molecules tend to form H-bonds?

Any molecule in which H is bonded to Fluroine, Oxygen, or nitrogen.

8. What causes London Forces?

London Forces are instantaneous dipole forces. At any given instant, there may be more electronic charge on one side of the nucleus than the other, which results in a separation of charge and a small dipole moment.

Monday, February 20, 2012

Honors Chem Feb 20-24

HONORS CHEM: Feb. 20-24, 2012 Name_______________________________

Tentative Schedule Date_____________________Pd_________

Write the Question and the Answer to all ELO problems. Show all math work

MON: No School – President’s Day

TUES: Discuss Ch 14 Worksheet #2

ELO: Study for test

WED: Chapter 14 Test

ELO: Read pages 467-472. Define the nine words in boldface print.

THUR: Discuss Test and ELO

Notes: 15.1 Solubility, 15.2 Solution composition and PPM

ELO: p.473, Focus Questions #1,2,3; p. 499 #3

FRI: Discuss ELO

Notes: 15.3 Factors Affecting the Rate of Dissolution 15.4 Solution Composition:

Teacher Examples: p 474 Self-Ö Ex 15.1; p 476 Self-Ö 15.2

Classwork: p. 499 #12ac, 13ac, 15, 17 Answer for 17 is 4.8 g heptane; 2.7 g pentane

ELO: p. 499 #12bd, 13bd, 14, 16

SAVE THIS TO ATTACH TO YOUR HOMEWORK ON FRIDAY