The Plight of Onondaga LakeDun, Dunnn, Dunnnnnnn………

Everyone take a seat and get ready for the NEW SEMESTER!

Blog AssignmentsBlog AssignmentsEach Sunday, Holt will post 2 questions about the

topics being covered in class. You will have until Wednesday at 12:00

midnight to respond to them. Some of the questions will be based on a

calculation, some will be based on some conceptual understanding and some will be based on your opinion.

But you must base your opinion on some fact and list it.

Generally, I question will be a calculation-type question and the other will be one of opinion, based on research. Example of this might be…

Holt Post: Do you think that acid rain is a problem in the U.S.?

Student Post: No, I think that acid rain is a myth brought out by the media to scare us.

Blog AssignmentsBlog AssignmentsIf this was your post, you would receive

very little credit (if any). I am not interested in your opinion, unless

you back it up with something. Now, some questions I post for you might

be of a topic of which you have no opinion. The reason you have no opinion, is

because you know little to nothing about that topic.

Blog AssignmentsBlog AssignmentsSo, what I want you to do is do a little

research on the topic, get both sides of an argument and give me your opinion after you have reviewed the topic.

This is why I am giving you Sunday, Monday, Tuesday and most of Wednesday to respond.

Then you will have until Saturday at midnight to read a few of your classmate’s responses and comment back to them.

You may agree or disagree but again you need to support your position with fact or your opinion based on documented fact.

You will not need to respond to the calculation-type questions.

Blog AssignmentsBlog AssignmentsGrading—this weekly assignment will constitute your journal

part of your portfolio and ½ of your HW grade for a total of 15% of your total grade.

Below is the rubric for this grading…Respond to Post on Time 10 ptsAnswer to calculation problem is correct

10ptsOpinion response is documented with class notes or website 10ptsResponse to classmate is coherent and documented 10 ptsResponse is free of grammatical errors 10 pts

There is no partial credit for any of the categories listed above. So, 1 misspelled word earns you a 40/50 at best.

Blog AssignmentsBlog AssignmentsYou may continue to do the normal journals

for 2% EXTRA CREDIT added to your score at the end of the semester.

However, you may not miss a day and they must be written perfectly. There is no partial credit for extra credit.

LabsLabsWe will run our labs like a professional lab. I will be the “lab supervisor” and you all will be the

employees. Think of your grades as your paycheck. Each member of

the group starts with 10 points for the lab write up (book) and 10 points for laboratory technician behavior.

Each infraction below results in losing 1 point for lab technician behavior. The lab book will be graded as follows…pre-lab questions (2), introduction (2), materials and methods (2), data recording/graphs/tables (2) conclusion including post lab questions (2).

If you do not bring your lab book to class or you do not have the introduction written or you are not using the lab book throughout the lab, you will lose the points associated with the mistake—2 points if there is no intro, 2 points if you are not writing down the procedures as we go and 2 points if you are not writing data as we go.

LabsLabs Each group (department) will be led by a team leader who will be

in charge of the rest of the group.  Your job will be to keep your team in line, assign tasks and come

to the supervisor (me) when needed. If team members are not working or straying to other groups or

being loud—you and your team will all lose points. Your team may not come and talk to me and they may not ask me

questions. It is your job to make sure that your entire team understands the

lab and what we are trying to accomplish in the lab. I will come around and ask your team and you questions about the

lab. If a team member that I choose cannot answer the question, your

team will be penalized. It is also the team leader’s responsibility to explain the lab to the

entire class when picked to do so. The tasks being assigned by the team leader will be gathering

equipment, gathering chemicals, labeler, experimenting, collecting data, interpreting lab and explaining steps to group and cleaning up. 

LabsLabs The equipment gatherer must get the needed beakers, thermometers,

hot plates, etc as needed and put them back in their places after they are cleaned.

If equipment is left at your station or put away dirty the leader and equipment person will lose points.

The chemical gatherer must get the necessary chemicals used in the lab.

They must not take the chemicals from the prep table back to your table. If any chemicals leave the lab table, your team will lose points. (The

leader and the chemical person.) The labeler’s job is to make certain that all chemicals are labeled at

your station. If the supervisor comes to your lab station and there are any beakers,

test tubes, etc ,that have chemicals (including water) and they are not labeled, you will lose points. (The leader and the labeler.)

The experimenter is the person that carries out the experiment. I would suggest that everyone be involved in this even though one

person is truly responsible for this. However, if the experiment is not going as planned or there are

mistakes, broken glassware, spills, etc, the leader and experimenter lose points.

LabsLabsAlong with the experimenter there will be a main data

collector. Each person should be collecting data in their own books, but

if I come around, I will mainly look for the main data collection book or paper and check it.

The chosen data collector must produce this from their book or paper in their handwriting or the leader and data collector loses points.

There is also a person that is in charge of explaining the steps of the lab and interpreting the data throughout the experiment.

This person should know what is going on before it happens and be able to explain what the results mean.

They are responsible for making sure that each member totally understands what is expected and what is meant in each step.

If I come by and ask anyone in the group what is going on or what just happened or what was supposed to happen and they are unable to do it, that person the leader and the explainer all lose points.

LabsLabs The clean up person is in charge of clean up. The chemical person is to dispose of the chemicals and the equipment

person takes care of the equipment, but the clean up person makes sure that the table and sink are in perfect condition before the group goes back in to the room.

Failure to do so costs each person in the group points. You will notice that there are 7 jobs not including the leader of the

group. The leader may pick one of the 7 jobs to do along with their

leadership duties, however, no more. The leader is really in charge of all the jobs being carried out. But they are there to make sure that everything is being done by all,

not doing it all themselves. I will be watching closely to make sure that the leader isn’t hogging

the jobs and that the workers are working hard so that the leader needs to pick up the slack to save them.

Everyone must work as a team doing their own jobs. A group cannot do all the jobs together—someone must be in charge of each task.

Also there must be a sheet taped to your stations with the names of the group and jobs for each. If there is not a sheet taped to each station, then the entire team loses points.

LabsLabsAt the end of the lab, each member of the group is to

comment on how the behavior and work ethic of each member enhanced the productivity of the lab.

Were your group members helpful or not, did they take care of their responsibilities, were they actively involved in the experiment and either answering questions or asking questions for

clarification. You are looking to come up with at least 2 positive things

each group member did and 1 thing they need to improve upon next time.

These are strictly confidential and will only be seen by me. You will receive a copy of these comments when you turn

in your completed lab write up.

Environmental ChemistryOne of the hottest topics in today’s world is

environmental chemistry.Topics considering pollution, recycling, ozone

layer depletion, alternative fuels and global warming are all around us—newspapers, magazines, CNN, and regular cable TV discuss the possibilities of these environmental factors.

Environmental ChemistryWhat does the Bible state about our

stewardship toward the environment? Are we following God’s plan?

I am not going to tell you what to think about today’s environmental issues—enough people do that.

But I am going to ask you to think. I want you to have your own opinions about

this before the end of the school year.

Environmental Chemistry I have spoken to many educated people

about Global Warming and the Environment and their responses range from…

“I don’t care cuz I can’t change it” to…“There is no problem, it’s all a scam” to…“There is a problem, but I don’t know how to

fix it” to…“There is a huge problem and if we don’t fix

it, the Earth is toast.”But most of them have no background

evidence to support their thoughts or…They only look at one side of the argument.

Environmental Chemistry However, they act as though they know so much

about the topic because they spout off the most. This is annoying to me and… You are going to be different. I don’t care what your position is as long as you can

back up your thoughts and you have looked at arguments for and against your initial beliefs.

It is probably best to have no pre-conceived ideas at this point although that is going to be difficult.

Environmental ChemistryWe are going to use documented

environmental issues to learn chemistry for the rest of the year and shape our belief system of the environment of which we live..

Are There Problems at Onondaga Are There Problems at Onondaga Lake?Lake?

We are going to take a deeper look at We are going to take a deeper look at solution chemistry through a case solution chemistry through a case

study of Onondaga Lake in Syracuse, study of Onondaga Lake in Syracuse, NY.NY.

HW: Look up and define the HW: Look up and define the characteristics of an characteristics of an

unsaturated, saturated and unsaturated, saturated and super-saturated solution.super-saturated solution.

Get Sheets over by the window—it’s Get Sheets over by the window—it’s a Graph and the Solvay Process! a Graph and the Solvay Process!

Whoo-HooWhoo-Hoo

Onondaga LakeOnondaga Lake In 1847, the mayor of a middle-sized city in a developing country shared his vision for the lake

adjoining his municipality. Read what he had to say about his nice, little town…

Our beautiful lake will present continuous villas ornamented with shady groves and hanging gardens and connected by a wide and splendid avenue that shall encircle its entire waters and furnish a delightful drive for the happy and prosperous citizens of the town who will, towards the end of each summer’s day, rush to it for pleasure, relaxation or improvement of health.

--Harvey Baldwin

Onondaga LakeOnondaga LakeThis indeed was the scene in Syracuse, NY on

the banks of Lake Onondaga. The area prospered as a number of 5 Star hotel resorts dotted the shoreline, the citizens of the area rushed to it for play, and a thriving fishing industry sprang up.

But in 1920, the fishing industry and resorts were gone. The fish taken out of this lake are no longer allowed to be eaten. You are not allowed to swim in the cloudy waters. The city of Syracuse does not draw its water from this lake for human usage.

Lake Onondaga is now called one of the world’s most polluted lakes and the most polluted lake in the country.

Onondaga LakeOnondaga LakeAt first glance this may seem like a problem

only to the residents near the lake in Syracuse, but it is not.

This is an account of a typical risk/benefit dilemma that many other societies faced in the past are now facing or will face in the future.

Initially technology brought new opportunities and new prosperity to the shores of Lake Onondaga, but environmental deterioration began to negate those advantages—it is an account of industrialization on a developing society.

What went wrong?

Onondaga LakeOnondaga LakeThis story of salt, soda and Syracuse is on

of industrial development, environmental impact and technology’s response.

It begins with a look at the rich natural resource of the brine springs that made Syracuse an ideal location for chemical manufacturing.

There was an increasing need for sodium carbonate (soda ash) that was plentiful in this area.

With this great natural resource a chemical procedure called the Solvay Process was used to extract this compound.

Onondaga LakeOnondaga LakeThis process was revolutionary for its time and

was considered to be environmentally responsible.

However, over the years of using this process, a great amount of unused by-products began to wash into the lake and contribute to its contamination.

Along with the Solvay process, the chlor-alkali process, developed to produce chlorine and sodium hydroxide, released large quantities of toxic mercury to the already troubled waters.

These two processes along with an old way of wastewater treatment system, caused the lake to end up in the poor shape that it is today.

Onondaga LakeOnondaga LakeOnondaga Lake is about 4.5 miles long and 1

mile wide. Muskegon Lake is 5.5 miles long and 2.2 miles wide.

It has an average depth of about 35 feet. It drains into the Seneca River which empties into Lake Ontario.

The relatively small size misrepresents its importance.

It provides a textbook case of the impact of industrial processes on the environment and society.

The Native Americans were the first to discover the springs of brine (concentrated solutions of sodium chloride) that are common in this area.

Onondaga LakeOnondaga LakeBy around 1800, almost all of the salt

used in the U.S. came from this area.Two methods were used to produce salt

along the shores of the lake. The brine was boiled down in large iron

kettles heated by wood fires. As the water evaporated, the solution

became more concentrated.

Onondaga LakeOnondaga LakeAt the saturation point, the crystals

began to form on the surface of the liquid and on the sides of the containers.

The salt was removed with large wooden scoops and placed in baskets to dry.

However, as the forests were cleared for farmland and burned for fuel, the cost of this method became too expensive.

Onondaga LakeOnondaga LakeThen they moved to a solar process where

the sun evaporated the brine to reveal the salt crystals.

However, salt mines were discovered in the west and in other more sunny areas of which took over the salt yards and by 1926, the last of the Onondaga salt yards closed.

However, before the salt mines had closed a process was discovered whereby sodium carbonate was made from sodium chloride.

Sodium carbonate is used in the manufacturing of soap, paper, water softeners and glass.

Onondaga LakeOnondaga LakeEven today sodium carbonate ranks

11th among industrial chemicals produced.

As a water softener, the carbonate ion (CO3

2-) reacts with calcium and magnesium ions in a double replacement reaction whereby insoluble CaCO3 and MgCO3 are formed and settle to the bottom of the tank.

In the very early days sodium carbonate was produced by extracting the ashes of seaweeds.

Onondaga LakeOnondaga LakeThis was a tedious process and the

demand for this product was much greater than what could be produced. Enter…technology.

In 1865 Albert and Ernest Solvay came up with a way to manufacture sodium carbonate from sodium chloride.

The Solvay Process starts with two of the cheapest and most abundant chemicals in the Earth’s crust: NaCl and CaCO3.

The overall reaction is 2NaCl + CaCO3 Na2CO3 + CaCl2

Onondaga LakeOnondaga LakeThe starting materials for the Solvay Process

were available in abundance near Syracuse. For this reason it is not hard to understand

why in 1884, the Solvay Process Company began making sodium carbonate along the Onondaga.

In fact, from 1960 to 1985, 2000-2800 tons of Na2CO3 were produced daily by Allied Chemical Company, the successor to the Solvay Process Company.

This booming industry gave the residents jobs, great public schools with extensive athletic, music, art and other extracurricular activities—even dental care was free for students.

Onondaga LakeOnondaga LakeHowever, with time, it became obvious that

the Solvay Process was also contributing some less desirable by-products to the town and to Lake Onondaga.

One key point is that the reaction above does not occur directly.

If you mix NaCl, CaCO3 and water, the NaCl would dissolve and the CaCO3 would not.

No reaction would take place and no sodium carbonate would be formed.

A series of reactions with a variety of by-products would need to be made to get to the end product.

Onondaga LakeOnondaga LakeSome of those by-products are NH3, NH4Cl,

CaO, Ca(OH)2, CO2 and NaHCO3.A particularly crucial step involves four of

these compounds. It is the reaction that occurs when CO2 and

NH3 are bubbled through a salt solution at 0°C.

NH3(g) + CO2(g) + NaCl(aq) + H2O(l) NaHCO3(s) + NH4Cl(aq)

In this equation we see that sodium bicarbonate is produced as a solid and ammonium chloride is produced dissolved in solution.

Onondaga LakeOnondaga LakeBoth of these chemicals form in the water

solution, but under these cool conditions the solubility of the NaHCO3 is less than that of the NH4Cl.

The solubility curve of these two compounds show this phenomenon.

The line for each shows the amount of compound that will dissolve per 100mL of water solution.

Onondaga LakeOnondaga LakeYou can see that at all temperatures the

ammonium chloride will dissolve more solid than sodium bicarbonate.

So at 0°C the solubility of NH4Cl is about 30g / 100mL whereas the solubility of sodium bicarbonate is only 7.0g / 100mL.

This means that the sodium bicarbonate crystallizes, separating as a solid, while the ammonium chloride remains behind in solution.

Onondaga LakeOnondaga LakeTo illustrate this process of fractional

crystallization, suppose we start with 100mL of a solution containing 12.0g of NaHCO3 and 24.0g of NH4Cl at 50°C.

The solution is cooled to 0°C.Only about 7.0g of NaHCO3 will stay in

solution whereas all the NH4Cl will be in solution. So, the only compound precipitating out will be the NaHCO3.

Onondaga LakeOnondaga LakeSo, the amount of NaHCO3 that

crystallizes out will be 5.0g.The percentage that remains in solution is

7.0/12.0 or 58% and the amount that precipitates out is 5.0/12.0 or 42%.

The solid sodium bicarbonate is filtered out and then this solid is converted to the desired Na2CO3 by heating it to about 300°C…

NaHCO3 + heat Na2CO3 + CO2 + H2O

Time to Put this Solvay process together…Sit down and get out your notes and your

solubility curves and your Solvay Process summary sheets…

We need to start right away so that we can get through everything to be ready for our Lab on Friday…

Write your name on a small piece of paper and give it to me

Your TurnYour TurnSuppose that 100mL of a solution containing

40.0g NH4Cl and 10.0g NaHCO3 at 40°C is cooled to 0°C. Calculate the masses of each

compound that would crystallize and the masses of the two compounds remaining in

the solution. Would this be a good method for obtaining pure NaHCO3?

The Solvay Process SummaryThe Solvay Process SummaryWe want this reaction (we want sodium carbonate)…NaCl + CaCO3 Na2CO3 + CaCl2

But the Solvay process had to get around the insolubility of calcium carbonate.

step (1) calcium carbonate (limestone) is heated…CaCO3 + heat CaO + CO2 step (2) ammonia, CO2 from step 1, salt and water

react…NH3 + CO2 + NaCl + H2O NaHCO3 + NH4ClStep (3) sodium bicarbonate is heated…2 NaHCO3 + heat Na2CO3 + H2O + CO2 step (4) the ammonium chloride and calcium oxide

react…2 NH4Cl + CaO 2 NH3 + H2O + CaCl2

Not re-used

Your TurnYour TurnIf in this step, 34.5g of NaCl was used in excess NH3, CO2 and H2O, how much solid

NaHCO3 and solid NH4Cl would be produced?

How much Na2CO3 would be produced from the previous amount in step 3?

Today in ChemToday in ChemSit at your desk and quickly contemplate the life of

a ground hog. This should only take about 5-10sec. Next, get out your solubility curve, Solvay

Summary sheet and your notes.Take out a sheet of paper—not part of your notes

and get ready for a quiz…I want to show you a video of a cool Friday Fire

experiment I would like to try tomorrow because lab went so well on Friday…

If you bring in supplies—you can play with the fire. If not, you can just watch.

Surprise Quiz (no talkingSurprise Quiz (no talking—you have 8 minutes to —you have 8 minutes to turn this in…)turn this in…)Let’s say that you were working for the Solvay

company and Big Man Solvay wanted to test your understanding of his system.

He looks you square in the face and says, “OK Mr./Ms. Smarty Pants. If I used 30.0g of pure

sodium chloride, how much sodium bicarbonate could I make? At what temperature would I

need to carry this out to get pure SB and how much pure SB would I make? How much

sodium carbonate could I make in step 4 from this amount of sodium chloride?”

Review Questions from Some HW___ ___________ solution is one in which more

solute could still be added.___ ___________ solution is one in which no

more solute could be added at this temperature and dissolve.

___ ___________ solution is on in which more solute was forced into the solution by adding heat and then slowly cooling it down so that the solute stays in the solution.

If the solution is cooled rapidly, or it is disturbed, the solute will come out.

Back to Notes on Back to Notes on Onondaga LakeOnondaga LakeFrom what we have stated thus far, it

would seem that the Solvay Process would be an ideal example of enlightened chemical manufacturing.

Two cheap and plentiful naturally occurring substances—salt and limestone—are converted into two useful products—sodium carbonate and calcium chloride.

However, CaCl2 is not in as demand as Na2CO3.

Onondaga LakeOnondaga LakeCaCl2 is used in concrete mixtures, to

melt snow and ice and in certain solar heating units to name a few.

But over the years the sales of calcium chloride from the Onondaga plant did not keep pace with the sales of sodium carbonate.

The excess calcium chloride was allowed by state and federal regulations to be dumped in solution into a tributary of the Onondaga Lake.

Onondaga LakeOnondaga LakeAlso large amounts of unmarketable salts

were dumped into solitary marshes along the coastline of Onondaga Lake—up to 500 tons every day.

It was mostly CaCl2 but also some un-reacted NaCl and CaSO4.

However, calcium, sodium and chloride ions leached from the marshes by rainwater into the lake.

Onondaga LakeOnondaga LakeIn 1943 a barrier holding back a waste

bed measuring 70 feet high and covering 400 acres of area broke and released a flood that buried over 20 houses.

Most of the substances in the waste beds are ionic compounds.

Their water solubility is very important to the composition of Onondaga Lake.

Some salts including NaCl and CaCl2 are water soluble—others such as CaCO3 are not.

Onondaga LakeOnondaga Lake The following solubility rules will help us

understand which ionic solids are generally soluble in water and which ones are insoluble in water. 

1. Salts containing Group 1 metals and the ammonium ion are soluble in water.

2. Salts containing nitrates and acetates are soluble in water.

Onondaga LakeOnondaga Lake3. Salts containing halogens (except F) are

soluble in water unless they are combined with Ag, Hg or Pb.

4. Salts containing sulfates are soluble in water unless they are combined with Ag, Hg, Pb, Sr, or Ba.

5. Salts containing sulfides, oxides, phosphates, carbonates and hydroxides are insoluble unless with Group 1 metals and NH4+.

Your TurnYour Turn Using the solubility rules, determine if the

following salts are soluble…1. Magnesium hydroxide2. Barium sulfate3. Lithium carbonate4. Strontium nitrate

Onondaga LakeOnondaga LakeSolubility rules also help us predict the

reactions that occur when solutions containing certain ions are mixed.

This information, in turn, helps us understand the chemistry of Lake Onondaga.

For example, over the years large amounts of water soluble NaCl and CaCl2 made their way into the lake.

Also large amounts of CO32- are found in the

lake.

Onondaga LakeOnondaga LakeWhen Ca2+ ions enter the lake and combine with

CO32- ions, insoluble CaCO3 is formed in the lake.Ca2+(aq) + CO32-(aq) CaCO3(s) is a net ionic

equation. NIE only show the ions that combine to make a reaction.

Other ions are present in the solution but stay as ions. They are called spectator ions because they are not participating in the reaction.

The deposition of CaCO3 in the lake has increased the sedimentation rate of the lake and a large CaCO3 delta exists where Ninemile Creek flows into the lake.

In short, Lake Onondaga is a saturated solution of CaCO3. HW: What is a delta? Are deltas harmful?

Life in Chem for Life in Chem for Today…Today…Lab TalkTough QuizEZPZ Notes of Net Ionic EquationsWork on HW (NIE) or Make Some

Fireballs (if you have material—you can make some, if not, do your HW and see fire near the end of class)

Lab TalkLab TalkLab write ups are due on Thursday—along with peer

review.You need Intro, Mat/Methods, Data Table,

Conclusion.Remember, in the conclusion you will need to summarize the key parts of the experimentto decide whether your experiment has supported

your hypothesis or not. So, restate your hypothesis and state how it has or has not supported it with data

Use the post-lab questions throughout the lab to further explain your understanding of the lab

Explain if you believe any errors were made, and how they could be avoided in future labs—what was difficult that you think others might need to watch for when they try your lab?

Tough Quiz…Tough Quiz…It is your goal as a scientist to make the most amount of

Na2CO3 as possible from the Solvay Process. Each day you obtain 100kg of NaCl free of charge.You buy ammonia for 12 cents per gram from a local

manufacturer and you have free water and free CO2, as well.

You are able to sell your sodium carbonate for 13 cents / gram.

If the process takes 4 hours to complete for 50 workers making $25 per hour each, plus $800 per hour operating costs. How much money can you make in an 8 hr work day?

Holy Baloney, Mr. Holt! How do I start this?Hint: How much NaHCO3 and NH4Cl can be made?Hint: How much NH3 is needed?Hint: This all takes place in a 350L tank. How much

NaHCO3 dissolves in that much water at 0ºC?You do the rest…

Chem Today…“The (wo)man who knows how, will

always have a job. The (wo)man who knows why, will be the first (wo)man’s boss.”

Yah, baby, ponder that!Talk about yesterday’s BEAST problem.Talk about Question #1 blog thoughts.Notes on Net Ionic EquationsHW on Net Ionic Equations

Beast Problem Revealed…The amount of NaHCO3 produced is roughly 144,000g.

The amount of NH3 used is roughly 29,000g.Solubility of SBC at 0ºC is 7g / 100mL.We have 350L or 350,000mL so FL or prop gives us…24,500g of SBC that will dissolve.144,000g produced – 24,500g still in sol’n = 119,500g solid119,500g SBC produces roughly 75,000g Na2CO3 that we

sell.We sell 75,000g of SC at 13 cents / g or $9750.We bought 29,000g NH3 at 12 cents / g for $3480.50 workers at $25 / hr for 4 hours (1 batch) = $5000.4 hours of operating cost at $800 / hr = $3200.Total cost = $11680 for 1 batch (4 hour period)Total $$ brought in for sales of SC = $9750Net = -$1930 per 4 hour batch or -$3860 per 8 hour day.

Your blog answers…Your blog answers…Here is your typical employee stats scaled down

to a salary of $100…

Home mortgage = $30Car payments = $15

Utilities = $5Food = $15

Gas and Misc. expenses = $20Credit Cards = $15

Total expenses = $100, subtracted from their take home pay leaves $0 for savings.

Is this what you tell them... “Too bad, so sad, you got into this mess, so it is your fault.”

Your blog answers…Your blog answers…If you cut their salary by 30-40%, what would

happen to them?Ask your parents how your lives would change if

their employer told them they were going to cut their salary by 30-40%?

Typical (not all) people live just above their wages—even owners of businesses.

If you get a raise…you buy a bigger house, car, coat, cabin, etc.

For those of you that answered that you would take a pay cut as the big boss…could you, if you lived just above your means?

Net Ionic Equations…Net Ionic Equations…Not in the notes…Writing net ionic equations.Write a balanced chemical equation as normal.Look at each compound to determine if it breaks up in

solution (soluble) or remains as a solid in water.Use solubility rules for ionic compounds.Liquids and gases do not break up in solution. (These

will be molecular compounds).Break up strong acids…HCl, HBr and HI are strong (know them).Acids with 2 or more oxygen than hydrogen are

strong.HNO3?H2SO4?HClO2?

NIENIESoluble or not?NaBrWrite as broken up ions…Na+ + Br-

What about CaCl2?Ca2+ + 2Cl-

How about HNO3?H+ + NO3

-

And finally, AgBr?It is insoluble so leave it alone—AgBr

NIENIEWrite the net ionic equation for silver nitrate

solution reacting with copper (II) chloride solution.AgNO3 + CuCl2 DRAgNO3 + CuCl2 Cu(NO3)2 + AgClBalance…2AgNO3 + CuCl2 Cu(NO3)2 + 2AgClAgNO3 is soluble2Ag+ + 2NO3

- + CuCl2 Cu(NO3)2 + 2AgClCuCl2 is soluble2Ag+ + 2NO3

- + Cu2+ + 2Cl- Cu(NO3)2 + 2AgClCu(NO3)2 is soluble2Ag+ + 2NO3

- + Cu2+ + 2Cl- Cu2+ +2NO3- + 2AgCl

NIENIEAgCl is insoluble2Ag+ + 2NO3

- + Cu2+ + 2Cl- Cu2+ +2NO3- +

2AgClCross out spectator ions—the ions that stay

the same on both sides of the equation.Write the ions and compounds that

remain…2Ag+ + 2Cl- 2AgClReduce coefficients if possible.Ag+ + Cl- AgClWrite in states.Ag+

(aq) + Cl- (aq) AgCl(s)

Yay! The net ionic equation…

Today in Chem…Today in Chem…Go over a bit of the HW.Quiz collected for HW grade (you be the engineer).

No giving up on the quiz—you can pout or get mad at me, but you cannot quit!

Quiz for HWQuiz for HWIf a solution of lead (II) nitrate was mixed

with a solution of potassium iodide, what would the net ionic equation look like?

+

Pb(NO3)2 KI

Pb2+ and 2NO3-

Pb2

+NO3-

I-

K+NO3-

K+ and I-

K+I-

Pb2

+

NO3- NO3-

K+ K+

I-I-

Pb(NO3)2 + 2KI PbI2 + 2KNO3

PbI2

Quiz for HWQuiz for HWQuestion 2 is a bit tougher…Think about the Solvay Process and all the

steps that must occur to produce and recover and re-use materials.

It is your job to come up with a sketch for a Solvay Plant that will produce Na2CO3.

Explain each step of the process…

NH3 bubbled in

NH3 gas tank

NaCl in water

What else reacts in this tank?

Where does it come from?

What is made in this tank?

Where does it go?

What else is being made at other points in this process?

What are the temperatures of the tanks?

Today in the Life of an Honors Today in the Life of an Honors Chemistry Student…Chemistry Student… Take a graded quiz Notes on Concentration Next Lab Handout

Quiz Quiz 1. magnesium sulfide + nitric acid 2. chromium (III) nitrate   +  barium metal   

   3. potassium phosphate + aluminum nitrate  

ConcentrationConcentrationQualitatively, the concentration of a solution can

be said to be strong or weak.However, chemists want to be a bit more

accurate in their description…so they use a quantitative measurement.

In general concentrations are measured as the amount of solute dissolved in a certain amount of solvent.

You already know about molarity.Molarity is the moles of a solute in a liter of

solution.

ConcentrationConcentrationIf you added 5.0g of sodium bicarbonate to a

100.0mL solution what would the molarity of that solution be?

Mole Fraction (X)Mole Fraction (X)Mole fraction (actually written as a decimal)

is the moles of solute (or solvent) / total number of moles in the solution.

If you mixed 2.0 moles of NaCl in 7.0 moles of water, the mole fraction of solution that is NaCl is…

2.0 moles NaCl / 9.0 moles all = 0.22 NaClYou can also say that the mole fraction that is

water is 0.78.

Mole FractionMole FractionIf you added 5.0g of sodium bicarbonate to a

100.0mL of water, what would the mole fraction of NaHCO3 of that solution be? (Density of water is 1.0 g/mL)

Riddle…Riddle… Hello. I am about 8.5” wide and 11” long. I am white

with a lot of black dots on me. I am sitting with my twin brothers and sisters next to the overhead projector. Please pick me up, take me home, read me and do as I say. Bring back your responses tomorrow for the really cool guy in the front to see. What am I?

Hello. There are 3 parts to me. One is very EZ, the second is a little tougher and the 3rd part of me is quite a thinker. I am very good for you, although you don’t like me most of the time. You will need a sheet of paper, a calculator, your periodic table and notes to fully understand me. Get ready for me. What am I?

Today’s Quiz Today’s Quiz (2 EZs (2 EZs and a Thinker and a Thinker))1. Write a net ionic equation for a solution of

aqueous cobalt (II) chloride reacting with sodium hydroxide…

2. What mass of solid AgBr is produced when 100.0mL of 0.150M AgNO3 is added to 20.0mL of 1.00M NaBr?

3. A nearby lake may be polluted with Pb2+ ions. How might you test the concentration of lead (II) ions in this lake?

The LabThe Lab The goal of the lab was to create a solubility

curve for KNO3. The point at which you noticed crystals is called

the saturation temperature. This is the temperature at which no more solute

(KNO3) can stay in solution. You found 6 saturation temperatures that you

must put on to an Excel chart. The x-axis is temperature (ºC) and the y-axis is

the amount of KNO3 in g that can dissolve in 100g of water.

The LabThe Lab Example: if your data showed the crystals

began to form at 67ºC for the test tube with 1.8g of KNO3 in 2.5g of water, how much KNO3 could dissolve in 100g of water?

Answer: 72g So, on your chart at the 67ºC mark you would

create a point at 72g. Do this 5 more times and draw the curve for

your chart. Get the “real” curve from a source on-line and

paste both in your lab books—call one Figure 1 and the other Figure 2.

Today’s AgendaToday’s Agenda Quiz (1Q over net ionic equations) Notes on concentration Lab books due Thursday Mid Chapter Quest on Friday (Onondaga,

Solvay, Net Ionic Equations, Concentrations, Solution Stoich and Solution preparations / dilutions)

Then next week, Friday, we will have another end of Chapter Quest—these 2 quests will be averaged into one quest.

If God exists, does it matter if I believe it? If God doesn’t exist, does it matter how much I

believe that He does?

Today’s QuizToday’s Quiz 1. Write a net ionic equation for a solution of

aqueous iron (III) chloride added to an aqueous solution of sodium sulfide.

Review Mole FractionReview Mole FractionIf you added 15.0g of sodium chloride to a

100.0mL of water, what would the mole fraction of NaCl of that solution be? (Density of water is 1.0 g/mL)

moles of NaCl = 0.256 molmoles of H2O = 5.56 molmole NaCl / total moles = X0.256 / 5.816 = 0.044 = XNaCl

% Concentration% ConcentrationIf you want to know the concentration as a

percent by mass you need a couple of things.The first is what mass of solute you have and

the other is the mass of water you have.% by mass = (mass solute / mass solution) x

100So, if you added 3.5g of NaCl to 96.5g of water

you have a solution that is 3.5% NaCl by mass.This means that of the total mass of the

solution, 3.5% of it is NaCl.

% Concentration% ConcentrationIf you added 5.0g of sodium bicarbonate to a

100.0mL of water, what would the percent by mass of NaHCO3 of that solution be?

Molality (m)Molality (m)Molality (m) is another measurement for

concentration.It is similar to molarity (M).Molarity is moles solute / L solutionMolality is moles solute / kg solventSo, if we have 0.30 moles of CaCl2 in 500.0g

of water, we have a concentration that is…0.30 mole / 0.500kg or 0.60m

ConcentrationConcentrationIf you added 5.0g of sodium bicarbonate to a

100.0mL of water, what would the molality of that solution be?

Parts per million Parts per million (ppm)(ppm)Often when the concentration of a solution is very

small, the previous methods do not look as nice.So, in these cases ppm or ppb are used.Parts per million (ppm) tell you how many parts

are present in a million total parts.Percent by mass is really pph (parts per hundred).If the % was 3.5%, that means that there are 3.5

parts per 100 total parts.You may use particles, ions, molecules, moles or

grams to figure ppm or ppb.

Parts per million Parts per million (ppm)(ppm)If you added 5.0g of sodium bicarbonate to a

100.0mL of water, what is the concentration of NaHCO3 in ppm?

We have 5.0g per 105 total grams or 4.8% or 4.8pph.

Set up a proportions of 4.8 / 100 = x / 1,000,000

Solve for x to get…48,000 ppm

Parts per million Parts per million (ppm)(ppm)If you added 0.0025g of sodium bicarbonate

to a 100.0mL of water, what is the concentration of NaHCO3 in ppm?

Diluting a SolutionDiluting a SolutionSometimes you have a solution already made that is

too concentrated to use for an experiment. How is a solution diluted?The equation used to determine how to prepare a

solution by dilution is…c1V1 = c2V2

c1 = concentration of the more concentrated solution

V1 = volume used of the more concentrated solution

c2 = concentration of the solution you want to make

V2 = volume of the solution you want to make

Diluting a SolutionDiluting a SolutionIf you need 150.0mL of a 2.5M solution of KNO3 for an

experiment and all you have is a bottle of 6.5M KNO3 solution, how would you make the desired solution.

We want (c2 and V2)

c2 = 2.5M

V2 = 150.0mL

We have (c1)

c1 = 6.5M

We need to use (V1)

V1 = ??

Diluting a SolutionDiluting a Solutionc1V1 = c2V2

V1 = c2V2 / c1

V1 = (2.5M ∙ 150.0mL) / 6.5M

V1 = 58mL—but this is not the answer…You were asked “How to make the solution”. So, to prepare this solution, you would take a 150mL

volumetric flask and add about 50mL of distilled H2O. Then you would add 58mL of the concentrated (6.5M)

solution of KNO3.Then you would fill the flask to the fill line with more

distilled H2O.

Your Turn…Your Turn… On a warm and sunny day in Philadelphia you start your

new job for a chemical research company. Your boss is kind of a jerk, but the pay is good and the benefits are better. As you were gazing out the window in a dream world, Dr. Smith comes up and asks you to carry out your first experiment. It calls for a reaction with 100.0mL of 2.0M silver nitrate and 85mL of 3.10M HCl. He points to a table full of chemicals and grunts—you assume he means to use these chemicals. So you do. There is a bottle of 12.0M HCl and a jar of AgNO3 solid crystals.

1. How would you prepare each solution (AgNO3 and HCl)

2. What is the balanced equation?3. What is the net ionic equation?4. How much solid product would be made in this reaction?

Your Turn…again…Your Turn…again…Predict what insoluble precipitates (if any) will form

when the following solutions are mixed. Write the net ionic equation for the precipitation reactions.0.10M NaCl and 0.10M AgNO30.10M BaCl2 and 0.10M MgSO40.10M KCl and 0.10M Cu(NO3)2

Proponents that claim that Onondaga Lake’s amount of CaCO3 is not a problem state that the excess CaCO3 neutralizes acid rain. Do a calculation to check their claim that 17,000 tons of CaCO3 could neutralize 3.0 x 1011 L of 0.0005M H2SO4 (acid rain).

Onondaga LakeOnondaga LakeLake Onondaga is very different from most

freshwater lakes due to its very high concentrations of various ions.

A typical lake has sodium ion concentrations below 10ppm and calcium ion concentrations below 50ppm.

Onondaga Lake has been measured at 550ppm Na+ and 500ppm Ca2+.

Where HCO3- is the most common anion in most lakes, Cl- is the most common anion in Onondaga.

Lake Onondaga also contains sulfate, nitrate, copper, chromium, cadmium and mercury ions as well.

Onondaga LakeOnondaga LakeThis last group of ions originally came

from manufacturing plants along the coast instead of the Solvay plant.

The fact that there is such a low concentration of phosphates is due to the large concentration of calcium ions in the lake.

Most of the phosphates introduced into the lake came from municipal storm and sanitary sewers that empty into it.

Onondaga LakeOnondaga LakeIn 1968, Syracuse and Allied Chemical

(owners of Solvay plant) entered into an agreement where the excess CaCl2 and Ca(OH)2 from the plant were used to treat the city’s wastewater.

The phosphates from the wastewater were combined with the calcium ions to form insoluble calcium phosphate which precipitated out before it reached the lake.