Blog Archives

binary, molecular formula naming/writing

10/31/2014

This is a brief post about Binary Molecular Formula Naming / Writing to accompany my previous posts on 10/17/2014 and 10/27/2014 about Ionic Formula Naming / Writing.

I have discussed Introductory Organic Formula Naming / Writing on 5/21/2014 with posts related to Organic Chemistry.

When teaching this topic, it is typical to address it briefly along with the Ionic Formula work.

FYI, using Percent Composition Data to Determining a Formula was addressed on 2/26/2014.

Here is a longer video (18 minutes) about Molecular Formulas (it's very comprehensive):

This narrator does talk about binary acids around 8:20 min. -- it's the teacher's choice whether or not to address the topic right now.

Here are a few worksheets focusing on Binary Molecular Formula Naming / Writing

http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&ved=0CAQQjBw&url=http%3A%2F%2Fimg.docstoccdn.com%2Fthumb%2Forig%2F26825858.png&ei=K5dTVKD7DufjsAT8qYGADA&bvm=bv.78677474,d.cWc&psig=AFQjCNGUMNwQ7ad48wMpix4yFDaqM6H9Fw&ust=1414850712299424

http://66.39.52.159/ddavis/PSif56.bmp

*Here is a two-page sheet that summarizes the topic of Ionic and Molecular Formula Naming and Writing:
https://www.ugdsb.on.ca/odss/Chemistry/ODSS%20CHEMISTRY/4C/Documents/Unit%201/Microsoft%20Word%20-%20Chemical%20Name%20and%20Formula%20Rules%20Handout.pdf

I have added a Topic List to help you to find past Blog entries. Check it out!

Buy my lab book "Chemistry on a Budget" -- it is available for $20 at amazon.com or $23 at lulu.com:

http://www.amazon.com/Chemistry-Budget-Marjorie-R-Heesemann/dp/0578129159/ref=sr_1_1?s=books&ie=UTF8&qid=1389410170&sr=1-1&keywords=chemistry+on+a+budget

http://www.lulu.com/shop/marjorie-r-heesemann/chemistry-on-a-budget/paperback/product-21217600.html

This book contains 13 labs using consumable materials purchased from local stores. There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the option! Each lab is two pages to allow for one two-sided handout.

Have a good weekend and Happy Halloween!

Ionic Formula Writing -- Part II

10/27/2014

I previously posted on October 17, 2014 with an introduction to Ionic Formula Naming / Writing that focused on binary formulas (those with just two elements).

Two skills that extend off this basic idea that are the focus of this blog post.

Objectives:

1. Write chemical formulas and names for the ionic compounds containing metals with multiple oxidation states (typically transition metals).

2. Write chemical formulas and names for ionic compounds containing polyatomic ions.

Here is a video that provides a quick 5-minute treatment of writing formulas of ions with multiple oxidation states:

BTW, iron is either +2 or +3 (it doesn't form negative ions), lead is +2 or +4.

The naming of ionic compounds with multiple oxidation states using Roman numerals was defined for general use in 1970 -- here is the publication produced by the International Union of Pure and Applied Chemists:
http://pac.iupac.org/publications/pac/pdf/1971/pdf/2801x0001.pdf

Before this, the naming system was a little more challenging to negotiate with suffixes such as "ic" and "ous" . Here is a page to provide some historical perspective:
http://www.chemteam.info/Nomenclature/Binary-Comm-FormulatoName.html

Another challenge in ionic formula writing is a compound with more than two elements, usually involving a polyatomic ion. Here is an 11-minute video segment addressing this formula writing challenge:

He does not use the "criss-cross" method here, but it can be applied for this type of compound as well.

He does discuss whether chemists write the parentheses in formulas, and I agree completely with those guidelines.

For my beginning students, I did allow the use of parentheses around the polyatomics, even if the subscript was the unwritten "1" -- this was just to learn to work with the polyatomics comfortably. I considered the parentheses as sort of a "magic shield" so that anything inside the parentheses stayed the same and the criss-cross occurred outside the parentheses.

This was simply a learning tool I used to make the formula writing with polyatomics less intimidating.

It is the teacher's choice of whether to have students memorize polyatomic ions. A list is in the NYS Regents Reference Table E:
http://www.p12.nysed.gov/assessment/reftable/chemistry-rt/chemrt-2011.pdf

In an Honors Chemistry course I taught, quizzes of (1) the polyatomic ions and (2) of ionic formula writing /naming was given.

For both quizzes, the student was given three tries for a highest score because the only reference was a periodic table without any charges, and there was no reference table of polyatomic ions.

This particular quiz policy was a precedent before I started teaching the course. One quiz was given in class, the other two were given after school -- the highest score of the three was the quiz that counted. I did observe significant improvement and it encouraged student mastery of these concepts.

Here are some worksheets focusing on ionic formula naming and writing:

This site contains several pages about ionic formula naming/ writing from which to choose:
http://www.mtlsd.org/teachers/smeer/stuff/chemical%20formulas%20all%20worksheets%202011.pdf

This ionic formula worksheet has answers:
http://misterguch.brinkster.net/PRA038.pdf

Here is more practice with binary ionic compounds:
http://www.kentschools.net/ccarman/files/2009/08/chemistry-naming_ionic_compounds_ws_1.pdf

And here is more practice with polyatomic ions:
http://www.kentschools.net/ccarman/files/2009/08/chemistry-naming_ionic_compounds_ws_2.pdf

If you are looking for another Chemistry subject, check out my Topic List -- it could help you to find past Blog entries.

*Another reference I just found is a TED Periodic Table that links the viewer to video clips about each particular element:
http://ed.ted.com/periodic-videos
Check it out!

Buy my lab book "Chemistry on a Budget" -- it is available for $20 at amazon.com or $23 at lulu.com:

http://www.amazon.com/Chemistry-Budget-Marjorie-R-Heesemann/dp/0578129159/ref=sr_1_1?s=books&ie=UTF8&qid=1389410170&sr=1-1&keywords=chemistry+on+a+budget

http://www.lulu.com/shop/marjorie-r-heesemann/chemistry-on-a-budget/paperback/product-21217600.html

This book contains 13 labs using consumable materials purchased from local stores. There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the choice of format! Each lab is two pages to allow for one two-sided handout.

I've edited this post to smooth out a few edges. I appreciate your patience during this gap in blog posts.

I will post briefly about Molecular Formula Writing this Friday, October 31st.

Have a good week!

Delay in Post & mole labs in my book

10/23/2014

I hope you had a wonderful National Mole Day! I’d love to hear about your class celebration!

Due to an unexpected delay, I will post next on Tuesday, October 28th -- the focus will be Ionic Formula Writing -- Part II.

In my lab book “Chemistry on a Budget”, there are several labs focusing on The Mole Concept:

"Catching Moles” which is good for grasping the concept as it develops and proves the utility of relative mass;
“Moles in Your Name?” using chalk, the blackboard and a balance; and
“Molar Volume” collecting a gas sample and gathering the measurements needed to calculate useful information.

You can buy my lab book "Chemistry on a Budget" for $20 at amazon.com or $23 at lulu.com:

http://www.amazon.com/Chemistry-Budget-Marjorie-R-Heesemann/dp/0578129159/ref=sr_1_1?s=books&ie=UTF8&qid=1389410170&sr=1-1&keywords=chemistry+on+a+budget

http://www.lulu.com/shop/marjorie-r-heesemann/chemistry-on-a-budget/paperback/product-21217600.html

This book contains 13 labs using consumable materials purchased from local stores. There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the option! Each lab is two pages to allow for one two-sided handout.

I have just added a Topic List to help you to find past Blog entries you're looking for. I hope it helps!

Have a good weekend!

celebrating mole day

10/20/2014

Mole Day is October 23rd, this Thursday! I posted a Mole Town Map on January 10, 2014 if you want to check that out.

My awareness of Mole Day has ranged from casually mentioning it in class (or forgetting it completely) to a major celebration with snacks and a party (that particular school's chemistry department traditionally did this). BTW, the party was in a lecture room and NOT in a lab! NEVER EAT IN THE LAB!

Celebrating Mole Day is a fun way to introduce the topic and make it memorable instead of menacing.

A little history:
The term "mole" is short for the German word "molekulargewicht" which translates to "molecular weight" . A scientist was writing a paper and was required to use the term molekulargewicht over and over, and subsequently shortened it to the phrase "mole" .

So, even though several images of moles as animals are used, no, it doesn't anything to do with the vermin. :-(

In searching for activities I found a video that I think is great!

Love it! The math on the board does not have units, which I don't agree with, but you'll deal with that...

The demonstration that it shown is melted potassium chlorate with a Skittles candy. The brand of candy doesn't matter and a gummy bear can be used. The demonstration produces a lot of smoke and could set off a fire alarm -- when I've performed it, it was in a fume hood.

If another teacher in your department had performed this demonstration, have them show it to you before attempting it.

*If no one in your department has performed it and you want to, work as a pair (or more teachers) to practice, wear safety goggles, perform this demonstration in a fume hood, and be aware of the potential fire hazard!

FYI, the test tube used will be destroyed by this demonstration and will end up in your glass disposal. Decide if you can sacrifice that glassware before you get started!

Here is a website devoted to National Mole Day:
http://www.moleday.org/

Here's a posting from the American Chemical Society with a few ideas for activities:
http://www.acs.org/content/acs/en/education/students/highschool/chemistryclubs/activities/mole-day.html

If students make items to celebrate Mole Day, some teachers offer it as an extra credit opportunity.

Here is a video that discusses the history of the development of the Mole measurement unit and gets into a little bit of Stoichiometry:

I have just added a Topic List to help you to find past Blog entries you're looking for. I hope it helps!

Remember to buy my lab book "Chemistry on a Budget" -- it is available for $20 at amazon.com or $23 at lulu.com:

http://www.amazon.com/Chemistry-Budget-Marjorie-R-Heesemann/dp/0578129159/ref=sr_1_1?s=books&ie=UTF8&qid=1389410170&sr=1-1&keywords=chemistry+on+a+budget

http://www.lulu.com/shop/marjorie-r-heesemann/chemistry-on-a-budget/paperback/product-21217600.html

This book contains 13 labs using consumable materials purchased from local stores. There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the option! Each lab is two pages to allow for one two-sided handout.

Have a good week!

Intro to ionic Formula writing

10/17/2014

This post is an Introduction to Ionic Formula Writing, beginning with the simpler formulas and worksheets, my later post getting into transition metals.

Here's an 11-minute video providing the basics of formula writing:

This is a good explanation but it does not use the Criss-Cross Method to determine the subscripts, which I'm very used to using. Here's a short video using this method:

Just to summarize: Cations are the ions of metals formed by losing electrons and have a positive electric charge. Anions are ions of nonmetals formed by gaining electrons and have a negative electric charge.

There's a minor mis-statement in this video -- teachers try to be perfect but little mistakes are made.

Here is a worksheet just for binary ionic formula writing:

http://chemsite.lsrhs.net/ChemicalBonds/handouts/binary_ionic_practice.pdf

This worksheet contains several pages, topics which I will address later -- you can pick and choose which pages to use in class:

http://www.epasd.k12.pa.us/cms/lib/PA09000081/Centricity/Domain/154/Writing_Formulas__Naming_Compounds_student.pdf

Next Friday, I will continue Ionic Formula writing with polyatomic ions and transition metals.

Mole Day is October 23rd, next Thursday! I am going to post a few Mole Day activities on Monday, 10/20.

I posted a Mole Town Map on January 10, 2014 if you want to check that out.

I have just added a Topic List to help you to find past Blog entries you're looking for. I hope it helps!

Buy my lab book "Chemistry on a Budget" -- it is available for $20 at amazon.com or $23 at lulu.com:

http://www.amazon.com/Chemistry-Budget-Marjorie-R-Heesemann/dp/0578129159/ref=sr_1_1?s=books&ie=UTF8&qid=1389410170&sr=1-1&keywords=chemistry+on+a+budget

http://www.lulu.com/shop/marjorie-r-heesemann/chemistry-on-a-budget/paperback/product-21217600.html

This book contains 13 labs using consumable materials purchased from local stores. There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the option! Each lab is two pages to allow for one two-sided handout.

Have a good weekend!

Unit objectives

10/15/2014

I talked about this topic several months ago, but I wanted to make this easier for readers to find:

During each Unit covered, I hand out a list of Objectives to my students. For the teacher, it acts as a check-list to make sure each topic is taught before moving on to others. For the student, it helps them to prepare for tests and quizzes and they could ask questions about topics they were unsure about. It's up to the teacher (you) to edit accordingly-- and you can announce to your students if you want to eliminate an objective. Just let them know! They'll appreciate that!

Here's a sample list using the topics from a previous blog post:

                                  Unit II Objectives: Isotopes and Related Topics
                                                      (Chapters 3 & 4)

1.            Define isotopes and atomic mass; calculate average isotopic mass from percent abundance data; report atoms and ions using symbol notation.

2.            Find the percentage composition of a given formula; use percentage composition to determine the formula of an unknown sample; find empirical and molecular formulas.

3.            Use facts and concepts presented in Chapters 3 & 4. (Be a careful reader!)

This last objective is a "cover all" objective that makes any topic addressed in the textbook chapters listed fair for quiz/test questions. I found it really useful when designing a quiz or test to make sure that each topic was addressed.

If there is a curriculum with objectives that you can access, that would be a great guide.

Just a reminder, I have just added a Topic List to help you to find past Blog entries you're looking for. I hope it helps!

Buy my lab book "Chemistry on a Budget" -- it is available for $20 at amazon.com or $23 at lulu.com:

http://www.amazon.com/Chemistry-Budget-Marjorie-R-Heesemann/dp/0578129159/ref=sr_1_1?s=books&ie=UTF8&qid=1389410170&sr=1-1&keywords=chemistry+on+a+budget

http://www.lulu.com/shop/marjorie-r-heesemann/chemistry-on-a-budget/paperback/product-21217600.html

This book contains 13 labs using consumable materials purchased from local stores.  There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the option! Each lab is two pages to allow for one two-sided handout.

I will be posting this Friday, October 17th as well.  Gosh, Mole Day approaches! (10/23 if you're not familiar with it). Let me know if you have any plans or activities!

elements, compounds & mixtures

10/8/2014

I know you've got a 3-day weekend coming up so I decided to post early.

Years ago I had access to a Coronet video called "Elements, Compounds & Mixtures". Using that theme, here are some resources that might be useful.

This web-page has a 20-minute movie titled "Classification of Matter" :
http://video.nhptv.org/video/2365088982/?utm_source=BlogLinks&utm_medium=AutoBlog&utm_campaign=nhptv_video_portal

This movie is a good overview of the basic ideas of Element, Compound, Homogeneous Mixture and Heterogeneous Mixture. A worksheet could be produced to keep the students on task, students could be required to record 10 facts from the video, or simply to record notes from the video.

At 7:30 minutes, the narrator eats food with the lab projected in the background. He is making a point about salt, but remember: NEVER EAT OR DRINK IN THE LABORATORY!

Also, boiling a salt water mixture on a hot plate to dryness can lead to solid salt with water vapor trapped underneath that "pops" out, also called "bumping" -- this can spatter the salt out of the beaker, reducing results if the goal is to separate the mixture.

There's a handy chart summarizing the main ideas at 13:55 minutes. There is also a nice quiz identifying various substances, and then explanations of each substance. This makes the video a nice resource for sub plans (just in case). There is a quiz in the last 3 minutes -- the first few questions refer to another video -- then it is a handy review of what was just seen.

Here is a Powerpoint presentation about Elements, Compounds and Mictures that also provides a useful overview of various physical separation techniques:
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=94&ved=0CC8QFjADOFo&url=http%3A%2F%2Fimages.pcmac.org%2FSiSFiles%2FSchools%2FAL%2FMobileCounty%2FMurphyHigh%2FUploads%2FPresentations%2FElements%2520Compounds%2520and%2520Mixtures.ppt&ei=d1c1VKaJMcSfyATQqIGIDg&usg=AFQjCNHAkzLRqFH-8sQ8Hc-MhI5GOzzXSw

Here are some worksheets about Elements, Compounds and Mixtures:

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=30&ved=0CF0QFjAJOBQ&url=http%3A%2F%2Fteacherpress.ocps.net%2Fpatriciadavis%2Ffiles%2F2013%2F09%2FE-C-or-M-.doc&ei=eVk1VLHyH4fbsAT7k4Fg&usg=AFQjCNFH69n7WpGUCH0G_-Tb3VOmgdb5Cw&bvm=bv.76943099,d.cWc
(the 3rd page is a blank)

http://sciencewithmsbarton.files.wordpress.com/2013/09/elements-compounds-mixtures-worksheet-modified.pdf

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=40&ved=0CE4QFjAJOB4&url=http%3A%2F%2Fsjdbh.ycdsb.ca%2Fdepartments%2FFOV1-0002BA05%2FS11B2382F-12245952.28%2Funit2insulatorsnconductors.ppt&ei=HV41VOi_PI_IsATj0YGIBw&usg=AFQjCNHpLVHTGJkBMKKuQvDa6goBedEFJg

This link contains several worksheets as well as a blank Periodic Table at the end:
http://staff.fcps.net/jswango/unit1/chap1/matter%20packet.pdf

Just a reminder, I have just added a Topic List to help you to find past Blog entries you're looking for. I hope it helps!

Buy my lab book "Chemistry on a Budget" -- it is available for $20 at amazon.com or $23 at lulu.com:

http://www.amazon.com/Chemistry-Budget-Marjorie-R-Heesemann/dp/0578129159/ref=sr_1_1?s=books&ie=UTF8&qid=1389410170&sr=1-1&keywords=chemistry+on+a+budget

http://www.lulu.com/shop/marjorie-r-heesemann/chemistry-on-a-budget/paperback/product-21217600.html

The book contains 13 labs that require consumable materials you can purchase at local stores.

Each lab is presented with two possible report formats -- both labs use the same procedure but each has a different conclusion -- one with 10 questions to be answered as a conclusion, the other with a full laboratory report required. This gives the teacher the option of what type of report is desired. Each version is designed to be just two pages. This way the teacher can photocopy just one 2-sided page per student (saves paper).

I hope your school year is going well! Write me to let me know about your triumphs, challenges and questions!

Have a great 3-day weekend!

heating/cooling curves revisited

10/3/2014

While searching for what topic to cover next, I see that many are visiting information previously posted about Heating/Cooling curves. The following adds to the previous blog entry.

Objectives:

1.     Describe the motion of particles of the three phases of matter according to Kinetic Molecular Theory.

2.     Interpret information from a graph of Temperature vs. Time during the heating or cooling of a substance.

Here is a video briefly discussing the motion of the particles in the three phases of matter according to Kinetic Molecular Theory. It's a little longer than 4 minutes:

At the end, the video shows demonstrations of liquid nitrogen and solid carbon dioxide (dry ice). If you have access to these substances, they are fun for demonstrations; however, it's not always easy to obtain these items or have the containers needed.

Here is a blank heating curve diagram that could be used for a lecture:

Here is a cooling curve for your reference as well:

Cooling curve for lecture

Here is a Powerpoint presentation that is a good overview, but uses some lab data:
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=126&ved=0CD0QFjAFOHg&url=http%3A%2F%2Fnoadswood.hants.sch.uk%2Fscience%2Fnoadswood_science_website%2FTopic_%28Year_8%29_-_Energy_%26_Electricity_files%2FHeating%2520%2526%2520Cooling%2520Curves.ppt&ei=1Z4uVMTzLMqKyAT2oYFg&usg=AFQjCNFFcN3JTx1GH9_A9Sv_tFNGXdO0rg

Previously on 3/2/14, I posted a lab about the heating and cooling of paradichlorobenzene. I realize that you may not be able to "sacrifice" too many test tubes and thermometers to this lab.

Here is a lab experiment based on the heating curve of water (a much easier substance to acquire), starting with ice:
http://www.saburchill.com/chemistry/lab/expt01.html

Here are two more water-based labs, but the set-ups are not illustrated:

http://schools.hwdsb.on.ca/highland/files/2013/01/Heating-Curve-lab.pdf

http://www.schaubscience.com/labs/HHeatingCurve.pdf

If you have access to temperature probes (such as Vernier or PASCO), here are a couple of labs that might be useful:

This is a little longer, but it's a Vernier lab:
http://www2.vernier.com/sample_labs/PSV-02-COMP-boiling_temperature.pdf

https://burdchem.wikispaces.com/file/view/Heating+Curves+Lab.pdf

http://www2.volstate.edu/CHEM/1030/Labs/Tempsm2a.htm

Here are more Worksheets for student practice of Heating/Cooling Curves.

This is very basic:
http://libby-teach.net/ch30s/Heating%20and%20Cooling%20Curve%20Worksheet.pdf

This worksheet is 3 pages:
http://www.cposcience.com/home/portals/2/media/post_sale_content/pfc2/ancillaries/skill_practice/9b_reading_a_heating_cooling_curve_pfc2.pdf

This worksheet contains several graph images that could be used in your own worksheets as well:
http://www.chemistryconnections.com/Particle%20Theory%20of%20Matter/heating%20curve%20ws%202009.pdf

I have just added a Topic List to help you to find past Blog entries you're looking for. I hope it helps!

Buy my lab book "Chemistry on a Budget" -- it is available for $20 at amazon.com or $23 at lulu.com:

http://www.amazon.com/Chemistry-Budget-Marjorie-R-Heesemann/dp/0578129159/ref=sr_1_1?s=books&ie=UTF8&qid=1389410170&sr=1-1&keywords=chemistry+on+a+budget

http://www.lulu.com/shop/marjorie-r-heesemann/chemistry-on-a-budget/paperback/product-21217600.html

The book contains 13 labs that require consumable materials you can purchase at local stores.

Each lab is presented with two possible report formats -- both labs use the same procedure but each has a different conclusion -- one with 10 questions to be answered as a conclusion, the other with a full laboratory report required. This gives the teacher the option of what type of report is desired. Each version is designed to be just two pages. This way the teacher can photocopy just one 2-sided page per student (saves paper).

I hope your school year is going well! Write me to let me know about your triumphs, challenges and questions!

Have a great weekend!