Monday, November 17, 2008

Periodic Trends Practice

http://www.sciencegeek.net/Chemistry/taters/Unit2PeriodicTrends.htm

Thursday, October 30, 2008

Unit 3 Test Study Guide Activity

Tomorrow's test will cover the standards listed on the Unit 3 - Study Guide.

Each group will need to do the following:
  • Come up with a consensus summary of the notes, activities and worksheets from your HW.
  • Come up with three multiple choice questions.
  • Solutions to multiple choice questions need to be emailed to Mr. Tran. Make sure you sign your group's name and period number and list the answers in the right order.
The best 2 multiple choice questions from each class will appear on tomorrow's test!

Monday, October 20, 2008

Selected Answers to Atomic Structure WS

H+

Atomic Number: 1
Atomic Mass: 1.0079
Mass Number: 1
Protons: 1
Neutrons: 0
Electrons: 0

Ag+1

Atomic Number: 47
Atomic Mass: 107.868
Mass Number: 108
Protons: 47
Neutrons: 61
Electrons: 46

Wednesday, October 15, 2008

Reading on Atomic Theory


Take a look at this reading to help you with tonight's HW:

Friday, October 3, 2008

Answer to Selected Density WS II Questions

3. 7.68 g/cc

5. 3.17 g/ml

7. 0.0081 g/cc; yes it will float.

The First 20 Elements

Follow this link to research the chemical and physical properties of the first 20 elements of the periodic table.

http://periodic.lanl.gov/default.htm

Monday, September 22, 2008

Answers to Selected Dimensional Analysis Practice Questions

10.) 30.0 lb/L

12.) 32,040,000 ft or 3.204 x 107 ft

13.) 1.80 x 103 yds/min

15.) 278 mg

If you would like confirmation of other answers, feel free to email Mr. Tran

Wednesday, September 17, 2008

Dimensional Analysis Project Links

For Background information on Olympic Medals:
www.bargaineering.com/articles/price-of-olympic-medals.html

To choose what year of the Olympics and find how many grams of each metal:
www.hesge.ch/heg/vous_etes/doc/stages/2004/sta04_schnyder_annexe1.pdf

For insight on how to solve this problem:
www.articlesbase.com/hobbies.../michael-phelps-olympic-medals-the-real-value-of-his-eight-gold-medals-526179.htm

Also, doing a Google Search on "Gold Commodity Price" will also give you a dollar amount. That is the cost per troy ounce.

Good luck!

Thursday, September 11, 2008

Scientific Notation and Significant Figures Worksheet Answers

Scientfic Notation

1. 5 x 10-3
2. 5.050 x 103
3. 8 x 10-4
4. 1 x 103
5. 1 x 106
6. 2.5 x 10-1
7. 2.5 x 10-2
8. 2.5 x 10-3
9. 5 x 102
10. 5 x 103

1. 1500
2. 0.0015
3. 0.0375
4. 375
5. 220000
6. 0.335
7. 0.00012
8. 10000
9. 0.1
10. 4

Significant Figures

1. 1
2. 2
3. 3
4. 4
5. 1
6. 4
7. 6
8. 1
9. 4
10. 5

1. Over the 4 with 3 s.f.
2. Over the last 0 with 3 s.f.
3. Over the 5 with 4 s.f.
4. Over the last zero in 2.000 with 4 s.f.
5. Over the last zero with 5 s.f.
6. Over the 1 with 3 s.f.
7. Over the 7 with 2 s.f.
8. Over the last 0 with 8 s.f.
9. Over the 1 with 3 s.f.
10. Over the last 0 with 3 s.f.

Friday, April 18, 2008

Thursday, March 27, 2008

Example Conclusion from Introduction to Solutions Lab

The purpose of this lab was to determine if a sugar cube or small grains of sugar would dissolve faster. Before doing this experiment, we predicted that the small grains would dissolve faster. We made this prediction because the sugar grains are not together and the water molecules would have easier access to them. During our experiment we saw that when the two types of sugars were stirred in the water, that the grains dissolved much more quickly than the sugar cube. This occurred in all three of our trials. On average, the grains dissolved in 1.24 minutes and the cube took 1.58 minutes to dissolve.
The sugar cube probably dissolved less quickly because it was more tightly packed and the water molecules couldn’t get to all of the sugar molecules all at once. The grains dissolved faster because they had more surface area, which allowed more water molecules to surround the sugar and dissolve it. Some possible sources of error in this experiment were issues with starting and stopping the stopwatch, losing sugar when putting into the beaker, and changing the stirring rate while dissolving. These errors may have affected either the time it took to dissolve the sugar samples or the time that we recorded. If I tried to do this experiment again, I might try to standardize the amount of sugar we add more precisely, and perhaps create a machine that would stir the solutions at an equal rate.

Thursday, March 6, 2008

Answers and Equations for "Stoichiometry and Percent Yield Practice"

2. Correct Formula: 2K + 2H2O --> 2KOH + H2
Answer: a. 1.25 mol H2
b. 83%

3. Correct Formula: 3CO + Fe2O3 --> 2Fe + 3CO2
Answer: a. 365.2 g Fe
b. 82%

4. Correct Formula: Ca + Cl2 --> CaCl2
Answer: 3.20 mol Cl2

5. Correct Formula: 2KI + Br2 --> 2KBr + I2
Answer: 41.2 g Br2

Tuesday, February 5, 2008

Single and Double Displacement Reactions (5.2) 2/5/08

Objective: SWBAT describe single and double displacement reactions

Agenda:
  • Toxins at Work

HW: Finish Toxins at Work HW

Monday, February 4, 2008

Balancing Equations (5.1) 2/4/08

Objective: SWBAT balance a chemical equation

Agenda:
  • Finish Drawing Out Reactions
  • First Balancing Worksheet (download)

HW: Finish "First Balancing Worksheet"

Thursday, January 24, 2008

Chemical Equations 1/24 Std 5.1

Objective: SWBAT make predictions using chemical equations

Agenda:
  • Making Predictions
  • Making Predictions HW

HW: Making Predictions HW

Wednesday, January 23, 2008

Chemical Equations 1/23 Std 5.1

Objective: SWBAT explain the parts of a chemical equation

Agenda:
  • Language of Change
  • Section Review #3 p 274

HW: Section review #3 p. 274

Tuesday, January 22, 2008

Molecular Formula 1/22 Std 5.4d

Objective: SWBAT determine the molecular formula from the empirical formula.

Agenda:
  • Review Test Study Skills
  • Percent Composition and Empirical Formula Quiz
  • Notes: Empirical Formula
  • Problems: p. 249

HW: Read pages 248-249 and do practice problems and Section Review Problems 1-4.  


Thursday, January 17, 2008

Video Tutorial: Mole Mass Calculations

video

Video Tutorial: Empirical Formula

Empirical Formula


video

Video Tutorial: Percent Composition

Percent Composition

After watching the video, try these Practice Problems. Answers are in [] for your reference:

NaCl [39.34% Na, 60.66% Cl]
(NH4)3PO4 [28.19% N, 8.11% H, 20.77% P, 42.93% O]

video

Wednesday, January 16, 2008

Empirical Formula 1/15/08 Std 5.4c

Objective: SWBAT determine the empirical formula of a substance.

Agenda:
  • Determining the Empirical Formula of Magnesium Oxide

HW: Finish Lab Analysis Questions

Thursday, January 10, 2008

Percent Composition 1/10/08 Std 5.4b

Objective: SWBAT determine percent composition of compounds

Agenda:
  • Notes: Percent Composition
  • Chewin' Through Chemistry


HW: Finish Chewin' Through Chemistry

Molar Mass 1/9/08 Std 5.4a

Objective: SWBAT calculate the molar mass of substances

Agenda:

  • Gram Formula Mass
  • Moley Stations
  • Mole-Mass Calculations Quiz (Std 5.4a)

HW: Read pages 242-244 and do practice problems on page 244

Tuesday, January 8, 2008

Answers to Selected Mass-Mole Calculations

Answers to Selected Gram Formula Mass problems.

5. 342 g Al2(SO4)3
13. 304 g Ba(ClO3)2

Answers to Selected Moles and Mass Problems

4. 0.99 moles KCl
4. 19 g KCl

Molar Mass 1/8/08 Std 5.4a

Objective: SWBAT calculate the molar mass of substances.

Agenda:
  • Notes: Mass-Mole Calculations
  • Gram Formula Mass
  • Moley Stations

HW: Complete Gram Formula Mass and Bring a Calculator!

Monday, January 7, 2008

Molar Mass 1/07/08 Std 5.4a

Objective: SWBAT explain what molar mass is for a substance

Agenda:
  • Molehill of Pennies

HW: Finish Molehill of Pennies and prepare for Molar Mass Quiz

Thursday, January 3, 2008

Chemical Formulas 1/1/08

Objective: SWBAT describe the molar mass of a substance

Agenda:
  • Moley Stations Activity
  • Sample Questions G and H p. 239-240

HW: Sample Questions G and H p. 239-240 (Must Show all Work!)