Sec 4 Chemistry Level Test (Duration: 1hr)

Dear 3A,

The topics that will be tested for the Sec 4 Level Test next year include all the sec 3 topics. However, more emphasis will be placed on the later topics as follows:

Chapter 13 & 14 (Metals)
Chapter 17 (Ammonia)
Chapter 23 (Air)

Next year will be a challenging year, so do revise your sec 3 concepts during the holidays and get yourself prepared. I can be reached via facebook inbox if you need any help. Happy studying!

Lastly.......Merry christmas and Happy new year in advance. See you in 2011!


Best regards,
Mrs Jeslyn Tan

Group Oral Presentation for Chapter 23 (Air)

Guidelines for Group Oral Presentation (02/11/2010 - 04/11/2010)

Grouping

• Form a group of 4 and assign a group leader. Group leader is to post the names of the group members and the sub-topic chosen in the comments section of this post by 28/10/2010 (Thursday), 12pm (Note: There will be one group with 5 members).

Group Work

• Select one sub-topic from the list given below.(Maximum 2 groups presenting on the same topic, based on first-come-first serve basis)
  
• Research on the sub-topic. You can use various resources e.g. the textbook, other reference books, online websites (make sure the information come from reliable sources).
• You may also want to research on interesting facts or real life applications.
  
• Group leader is to coordinate and allocate the tasks among the members.
  

Group Oral Presentation

1. Prepare a 10 mins oral presentation using powerpoint or keynote on your selected sub-topic. (Except: The group of 5 members will need to prepare a 15mins presentation excluding Q&A).
   
2. Each group will be given a maximum of 15 mins (including 5mins for Q&A).
3. Every group member must speak.
4. Remember to start your presentation by giving a brief background on the topic you have chosen and end your presentation with a proper conclusion/short discussion.
5. Date of presentation: 02/11/2010, 03/11/2010, 04/11/2010. Three groups will be presenting for each lesson.
   

Grading

• Your oral presentation will be graded based on content, organization and graphics, creativity, length of presentation and presentation skills.
  
• The grade given MAY be used as a class test component in Sec 4.
• Group leader is to submit a soft copy of the presentation slides to my email after your group's presentation for grading lim_jia_jia@mshs.edu.sg
  

Sub-topics on Air (chapter 23)

1) Carbon monoxide - state the sources; describe the reactions used in possible solutions to the problems arising from it; discuss some of the effects of this pollutant on health and on the environment

2) Sulfur dioxide – state the sources; describe the reactions used in possible solutions to the problems arising from it; discuss some of the effects of this pollutant on health and on the environment

3) Nitrogen oxides - state the sources; describe the reactions used in possible solutions to the problems arising from it; discuss some of the effects of this pollutant on health and on the environment

4) Ozone – briefly how it is formed; discuss the importance of the ozone layer; how layer is depleted; problems involved with the depletion of the ozone; possible solutions

5) Greenhouse gases – what they are; source of these gases; discuss the possible consequences of an increase in global warming; include some examples if possible

6) Carbon cycle – describe in simple terms, to include
-the processes of combustion, respiration and photosynthesis
-how carbon cycle regulates the amount of carbon dioxide in the atmosphere

7) ‘Acid rain’ – its formation and effects on respiration and buildings; give real life examples.

8) Air quality in Singapore- discuss with relevant data; green efforts/initiatives put in locally to combat air pollution

9) Many scientists have concluded that excess greenhouse gases cause global warming but others disagree. Collect information on the two sides to this argument :
Side A : global warming is real and requires immediate attention and action
Side B : scientists have not proven that global warming is serious and action
is not needed

10) Air – composition of clean air; why it is a mixture; separation of liquid air in the industries and its application.

Website for Chemistry ICT Worksheet- Metal Displacement Reaction

http://www.chem.iastate.edu/group/Greenbowe/sections/projectfolder/flashfiles/redox/home.html

June Holiday Homework 2010

Dear 3A,

Please read the following instructions for your June Holiday Homework:

• Each student is to prepare a Summary Notes on ONE of the topics which will be taught in Term 3. The topics will be assigned based on the class list. Please refer to the list below. You can use the Chemistry Insights textbook or other textbooks as a reference.
  

Layout of the Summary Notes:

• You can choose ANY layout (eg. a concept map using cMap, notes, point form, etc.)
• The summary notes should be a summary of the key concepts from the topic; and in such a way that it will be useful for your revision later.
• Minimum 1 full page. Minimum Font Size 12.
  

Note:

• The best summary notes for each topic will be selected and distributed to the whole class for as a supplementary notes for all. *Do look forward for additional surprises for the selected work! :)
  

Submission:

• Submit in hard copy during Term 3 Week 1. Please indicate your name, class, index no. and the assigned topic in your work.
  

Allocation of Topics:

• Chapter 15 (15.1 and 15.2) Acids --> Index No. 1-10
  
• Chapter 15 (15.3 and 15.4) Bases & Alkalis and Indicators & pH--> Index No. 11-20
  
• Chapter 16 (16.1, 16.2, 16.3, 16.4) Neutralisation and Applications --> Index No. 21-30
  
• Chapter 16 (16.5) Salts --> Index No. 31-37
  

Mrs. Jeslyn Tan

Amendments to Chapter 1 slides

Dear 3A,

The amended slides for Chapter 1 Measurements in Chemistry has been uploaded to Studywiz. The password to the document has been emailed to you via Studywiz. Just a gentle reminder to keep the password confidential.

Thanks.

Mrs. Jeslyn Tan

Tasks to-do on Thursday 08/04/2010 Period 3&4

Dear Sec3A,

You will receive a copy of the past year SA1 paper from the relief teacher today. Please attempt the questions on your own. Do not discuss with your classmates but you can refer to your notes if you need to.

Section A and B - do on the worksheet itself
Section C - do on foolscap paper

Let this be an assessment of how ready your are for SA1 at this point of time. You can skip the questions on chemical calculations as I have not covered the topic.

At the end of the lesson, please keep the worksheet with you and finish up the rest of the questions as homework over the weekend.

I'll collect the worksheet next week to check.

Mrs. Jeslyn Tan

Assignments During March Holidays

Dear Sec 3A,

While you are enjoying your March holidays, please remember to complete the following assignments:

1. Chemistry Matters Workbook, WS 5 Chemical Bonding (pg. 38-47).

2. The IT worksheet on the properties of diamond and graphite.

The above assignments will be collected during the first week of Term 2 for checking (including the workbook).

Mrs. Jeslyn Tan

Answers to Practise Worksheet for Chapter 4 (Elements, Compounds and Mixtures) notes

(a) A compound

(b) An element

(c) A mixture of element and compound

(d) A compound

(e) A mixture of elements

(f) An element

Homework for Week 3

Dear Sec3A,

Things to be done over the weekend:

1. Discussion thread on blog.
2. Worksheet 1 in Chemistry Matters Workbook
   
3. Part of worksheet 2 in Chemistry Matters Workbook(since I haven't finished the topic)

Make sure that at least you do the "test it" section. I will not upload the answers unless everyone has completed the worksheets. To be checked next week during theory lessons. Please help to inform your friends who do not have Macbook.

Chapter 3: Solid, Liquid and Gases

Dear Sec3A,

Please spend sometime to browse through the online resources that I've listed:

A Closer Look: Scientific Models
http://www.learner.org/courses/essential/physicalsci/session2/closer1.html

Three States of Matter at Molecular Level
http://mutuslab.cs.uwindsor.ca/schurko/animations/phasesofmatter/phasesofmatter.html

Phases of Matter in Container
http://mutuslab.cs.uwindsor.ca/schurko/animations/phasescontainers/phasescontainer.html

Videos on Changes of States
http://cwx.prenhall.com/petrucci/medialib/media_portfolio/text_images/031_ChangesState.MOV
http://www.educationusingpowerpoint.org.uk/Animations/change%20state.html

Discussion Thread: Pure Water for Singapore (Chapter 2)

Singapore is dependent on other countries for water. However, should these countries decide to stop their supply to Singapore, we would have inadequate supply of drinking water available.

With that in mind, the government has built a desalination plant in Tuas in 2005 which uses the cutting edge technology "reverse osmosis" instead of desalination to obtain drinking water from seawater. This plant supplies about enough water to meet around 10% of the national demand. The production of NEWwater from wastewater also uses the process of reverse osmosis.

Refer to textbook page 25 for the process of reverse osmosis.

Thinking questions:

1. Suggest possible reasons why Singapore decided to use reverse osmosis and not distillation to obtain pure water from seawater.
2. What are some of the strategies that Singapore has taken to diversify Singapore's water resources?

Note: Remember to end your comments with your names. Those (scholars) who do not have a MacBook, please pair up with your peers.

Online Resource:
http://en.wikipedia.org/wiki/Water_resources_of_Singapore
http://en.wikipedia.org/wiki/NEWater

Answers to Practice Questions in Textbook (chapter 1)

Structured Questions (Textbook pg16)

1.(a) Burette
(b) Beaker
(c) Test tube
(d) Measuring cylinder

2. (a) (i) Cubic metre, m3
(ii) It is a very large unit and so is less
convenient for the smaller volumes of
liquids usually encountered in Chemistry
experiments.

(b) (i) Cubic centimetre
(ii) cm3

(c) (i) Burette
(ii) To 0.1 cm3

3. (a) 53 cm3

(b) To the nearest cm3
(At ‘O’ Level, the volume in a 100 cm3
measuring cylinder is measured to the nearest
cm3 though more accurate readings may be
possible, e.g. 53.4 cm3.)

(c) In a burette, the gradations are reversed. The
zero is at the top of a burette, whereas it is at
the bottom of a measuring cylinder.

4. Balance, gram(g)
Thermometer, degree celsius(oC)
Measuring cylinder, cubic centimetre (cm3)
stopwatch, seconds (s)

5. (a) X – temperature sensor/probe.
Y-connector/interface/data logger.
Z – computer.
(b) (i) To measure the temperature of the reaction
mixture
(ii) To display the data on the monitor/screen,
often in the form of a graph
(c) (ii) Vertical axis – temperature. Horizontal  axis – time.

6. (a) During the reaction, the (carbon dioxide) gas
produced escapes from the flask.

(b) (i) Vertical axis – mass. Horizontal axis – time.

(iii) As the speed of the reaction decreases with time,
the gradient of the graph decreases. When the
reaction ends, the graph is flat/horizontal.

Free Response Question (Textbook pg17)

Place a bag of silica gel on a balance connected to a computer to record its mass over a period of time. The mass increases as water is absorbed. Plot a graph of mass against time. When the mass stops increasing, the silica gel is no longer absorbing wate