Give me a C! Two for One and Two for All!

The MePB of organic Chemistry was today, and boy, what a day. Even though we learned about most of these complex carbon compounds, functional groups, etc, before, it seemed so complicated all of a sudden. But the organic chemistry kits really helped us to "visualize the compounds, not just see lewis structures, and we could see how the carbons weren't actually lined up, but zig-zagged in a sort of way," like one Chemistry student replied.

So here's the general idea of organic chemistry, which is also the largest and most organized branch of chemistry. Carbon, because of its ability to make 4 strong bonds, is the underlying structure and foundation of most compounds. Hydrocarbons are the simplest examples. We reviewed the first 10 hydrocarbons in class again: methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, and decane. But before, we had only gone as far as drawing their Lewis structures and their 3-D models. Now we got to actually make the compounds using organic chemistry kits. Through these kits, we learned about structural isomers, compounds with the same formula but different arrangments of atoms and thus different properties. We learned how to name each of the compounds that we made and even listed all 18 isomers of octane. The next day, we advanced even farther by making alcohols and ethers, which is a combination of 2 alcohol groups.But what I enjoyed most out of these couple of days spent on Organic Chemistry was the Extreme Oreo Makeover Video. This video created by '09 alumni featured a film on the history of oreos. When it was first invented in February 1912, everybody loved to eat oreos because then, people believed that trans fat was healthier than saturated fat. After 1944, trans fat was discovered to be bad for the human body, even though it increases shelf life and flavor stability. Eventually, the oreo had to go through an extreme oreo makeover. Overall, this video was very amusing and fun to watch, and even though it may seem like an old film created simply for entertainment, "it really did teach us about many different aspects of nutrtion."

The Horrors and Joys of the Unit 7 Exam

The Unit 7 Exam was early this unit--it felt like we had barely begun the unit when we were sitting down for a test! The exam should have been an easy one--with more then 50% recycled quiz and pH questions, all available to us, the exam should have been a breeze.

...Only it wasn't.

Sayoni Saha, period 7, had mixed opinions. "I studied very hard, but didn't do well. Well, compared to others, I did okay, but I didn't do great. Mr. Bender said the test for period 7 was harder, and I think it was because we had less recycled questions. So I think I didn't do so well because the test was hard... I did all the pHs and used all the CHIPs to study, but I should have studied more comprehensively. I focused more on some stuff and on test, I didn't know how to do the problems which I didn't study for so well."

Catherine Qian regrets not having studied so much. She said, "I did badly. I really wish I had studied the pHs. When I was taking the test, I really felt that I would have done so much better if I had done all the pHs. It would also have helped me understand all the material in class too."

CST seemed to have helped students. Borah Lim, period 3, when taking the test, felt very confident because she had gone to CST. It helped her with a lot of material she had previously been confused about and was glad she had the opportunity to go. When taking the test, she felt calm because she understood all the material.

Michelle Lee, period 7, struggled through the exam. "I was my fault. I got confused in class and then didn't study, which was stupid. I really should have studied. I though the test was easy for those who knew the material, but I did really badly."

One student felt that she did badly because he had so little time before the test. "I did really badly. I tried to study, but I was really busy with my cpr. Well, Mr. Bender said it was hard, so that might also be a part of it. But I didn't do any of the pHs, which was really stupid. I should have done them. I was really busy last month, well this month too. I didn't go to cst, though I usually do."

I personally did not do too well on the test because I was confused on some really simple things that I thought I understood. As luck would have it, I messed up on the test ): The Unit 7 Exam didn't go down so well with many students--let's hope that they get their act together before their next quiz.

7 days. Pass it on.

A thrilling CPR investigation was presented to periods 2 and 3 today by Eric Hanamoto, Raymond Lin, Emily Liang, Stephanie Pascua, and Annie Yau. "A Breath of Biofuels," an informative horror video presentation, taught us about biofuels, which are any solid, liquid or gas fuels created from biomass. In their video, while hanging out in a classroom, a group of friends found a DVD about biofuels. But suddenly, some of the friends were murdered mysteriously. Later, it was discovered that if they didn't pass on the DVD after watching it to other people and spread the knowledge of biofuels, they would die in 7 days. Through the video and the explanations from the speakers in between, they taught us a lot about biofuels. Here's some of the things we learned.

• In July 2009, biofuels production was banned in CA because of safety reasons with the storage of pure biofuels. =/


• Ethanol may be an ALTERNATIVE FUEL, but it has its pros (safer, has same amount of CO2 emission as regular fuels) and cons (takes away corn supply, energy production is not efficient)


• Biofuels - made from oils and fats used for vehicles that run on diesel only; its the greener choice because it helps reduce air pollutants like carbon monoxide, hydrocarbons, and sulfur oxide.


• What's the future of biofuels? Much research is going on to see if biofuels really is a potential fuel alternative. Even though its production has tripled (4.8 billion gallons in 2000 to 16 billion gallons in 2007), today, it still accounts for less than 3% of the world's transportaion fuel supply.

This CPR video was one of the most interesting CPR presentations we've had this year. Many people agree that because the didactic film kept us students at the edge of our seats waiting to hear what would happen next, we became more interested in biolfuels. In addition, we learned more about potential sources of energy in the future that could be helpful to our environment, such as ethanol, biodiesel, and algae, which was the most interesting to me. Before, to me, algae was a plant that I learned about in Biology Honors last year. However, now, I know that algae can be another potential energy source because not only does it consume carbon dioxide as food, which would be a huge plus to our planet, its production and growth is also easier because it takes up less space. Overall, this was a fresh, funny, and suspenseful "breath of biofuels".

Sad Cornless Milley

Correction: You're in everything but Milley's belly. Poor Milley.

The Poor Hungry Children of America cpr began with Milley's story: She is a farm girl from the corn field of Iowa, who seen many families around her experiencing food shortages because their corn is being turned into ethanol fuel.

How is corn being made into ethanol fuel? Unfortunately, it's not as simple as sticking a gas pump into an ear of corn. There are 12 essential steps in the process.

1. Delivery of corn to the storage.
2. The corn is stored until ready to be processed.
3. Corn is made into flour.
4. Water and an enzyme are added to the flour to make a paste.
5. The paste is watered down.
6. Yeast is added.
7. Distillation to separate the stillage and the alcohol.
8. Dehydration to turn 190 proof into 200 proof.
9. Storage and transportation to be mixed with gasoline.
10. Seperating heavy solids and fluids.
11. Drying of solid
12. Collection of carbon dioxide for further marketing.

And then, ta-da! The E-85 that we can buy at pumps.

So if oil is a nonrenewable resource, and ethanol is, why don't we use it all the time? Well for one, to grow enough corn to support the entire United States with pure ethanol would require 97% of the arable land in the nation. That leaves about 3% to grow food and raise livestock. There is also the argument (and Milley's plight) that we should not take food away to make gas for our cars. However, it is widely used in some areas (most noticeable in the midwest).

When Mr. Bender visited, he saw many signs that declared certain corn fields for ethanol.

So the Poor Hungry Children of America explored other possibilities of renewable resources.

1. Biohydrogen: It can fuel without carbon dioxide emissions. Made from bacteria releasing H2. However, very expensive to create and inefficient.
2. Biogases: Contains methanol and landfill gas.
3. Bio methanol: Methanol made from biomass, which is a renewable resource. But it's very expensive because it requires so much biomass to produce only a little bio methanol.
4. Biodiesel: Already in use, it is made from oils or fats, even leftovers like from fryers at fast food restaurants! We do not need to modify our cars to use biodiesel.
5. Algae fuel: It is made by feeding excess CO2 to algae, then starving them. The algae breaks open, releasing oil. This is an efficient method because algae create lots of oil in a little amount of space.

Alternative fuels have come a long way. Will ethanol remain a prominent member of the club?

So much heat from such a little atom!

What do we think of when we think of nuclear? Radiation, explosion, bomb... all the stereotypical cons of nuclear power. Mr. Bender showed us a few clips concerning nuclear power and bombs: The Simpsons (in which a person glows very brightly due to continued exposure to nuclear power), The Sum of All Fears, and a clip from Indiana Jones (in which Indiana hides in a lead lined fridge to save himself from a nuclear bomb). Later in class, we learned of some of the pros of nuclear power and how helpful is could be, as is exemplified by the power plant in New York.

We viewed newspaper articles in class. One of the articles was about Iran, and their new uranium enriching machine. Iran can now process uranium faster, which means they'll have lots more uranium-235 on their hands. This was the cause of much commotion and protests from other nations, as this will make creating nuclear power that much easier for Iran ):

So what makes nuclear power so powerful?
It had all to do with heat, with the nuclear binding energy (NBE).
And the famous equation E=mc^2.

E=energy

m=mass
c=3.0x10^8

When the electrons, protons, and neutrons do not add up to mass of an atom, the mass deficit has been used as NBE. To calculate the NBE, you need only to plug in the mass deficit into the eqaution E=mc^2. Because c is such a great number, the tiniest mass losses can result in huge releases of energy.

Happy fish, dead fish, BEEEES!

Today we learned that radioactivity, the starting block of nuclear weapons and so on, was discovered by accident by Henry Bacquerel in 1896! Apparently, he had put a photographic plate in a drawer along with some uranium, and the next day, he discovered that they had been developed bye uranium's radioactivity. With this story, we jumped headfirst into the world of radioactivity, which is a spontaneous emission of particles and/or radiation from unstable nuclei. We were introduced to alpha, beta, and gamma particles.

Alpha decay, whose product isotope is called the daughter, can be blocked by paper. This process resembles a nucleus "coughing up" helium nucleus.

Beta decay, which can be stopped by concrete, is when a neutron turns into a proton.

Gamma decay, which has the highest amount of energy, can be blocked by lead.

Nuclear fission is when an atom splits into smaller atoms, while nuclear fusion is when atoms combine on the sun or in particle accelerators. These are both types of nuclear bombardment.

There are many stereotypes about radioactivity. Many, including myself until now, stereotypically think that radioactive elements glow green all the time. This can also be seen in one Simpsons episode when the whole town gets scared of an alien that is actually Mr. Burns on medication. Another interesting story we learned along with Henry's discovery by accident was about the radium girls. Watches were once painted with glow-in-the-dark paint. This paint was actually radioactive, but women who were assigned jobs to paint these watches put the paint in the mouths while sharpening the point of their paintbrushes as well as on their body for fun. Of course, this resulted in much damage to their health. :( What's sadder is that scientists knew about the detrimental effects of this spontaneously glowing paint, but they still allowed many people to suffer. All in all, radioactivity has a long history of accidents and harm.

Lazy shoelike electrons like to play monopoly!

Day 110: We learn about electron configuration. Mr. Bender gave us three words to simplify it. Lazy, shoes, and monopoly.

Lazy:

Electrons are "lazy", they like to stay at the lowest energy level possible. That means they won't be skipping any energy levels, or skip an energy level where there is only one electron. They stay as low as possible!

Shoes:

Electrons are like shoes, they come in pairs. In each level, there is a maximum is two electrons. When the energy level is filled with two electrons, the electrons have opposite spins and are denoted by up arrows and down arrows.

Monopoly:

Electrons like to "play monopoly". It is always singles first! They only pair up when necessary.

The first level is 1s, and includes Hydrogen and Helium and the second level is 2s. These are both spherical. The third level is 2p, and 2p has three different orbitals. 2Px, 2Py, and 2Pz. 3d, the fifth level, had five different orbitals.

To help us understand, Mr. Bender showed us an oh so wonderful video from the World of Chemistry where Don is a coach for the Electron Team Baseball. He showed us how electron configurations worked physically, using benches and baseball players to act as levels and electrons.

A rather simple and easy concept, compared to some of the pretty complicated things we learned this unit!

HUP HUP HURRAY!!

HUP. When I first saw this on CHIP 179, I was so lost. The comic strip at the top of the CHIP ("I can tell you the time or the place, but not both") only served to bewilder me even more. Luckily, by the end of the period, it all became clear to me as I realized that HUP wasn't hard at all! It was actually an entertaining day because Bender showed us HUP in Movies, so we ended up watching short clips from Jurassic Park: the Lost World and Star Trek.

In Jurassic Park: The Lost World, one of the main characters, in the middle of a jungle searching for dinosaurs, states that dinosaurs behave differently when they know that they are being watched. This amazingly related to how the electrons in atoms can't be "watched" because while we are shining radar right on them, the radar is changing their actions and speed.

Watching the clip from the beginning of Star Trek was even more exciting. At first I didn't understand why Mr. Bender would be showing us a extremely entertaining scene of a Robocop chasing James Kirk speeding in a car in class, but later I realized that the point he was trying to bring up was that James could have been speeding because the Robocop had used his radar gun on him. Of course, the radar gun was not to blame, seeing as the car's weight is much too large to be affected by a radar gun. Heisenberg Uncertainty Principle works for electrons, which have small masses. HUP stated that it's impossible to know the position and momentum of electrons at the same time. Even though I don't fully comprehend how this principle works, let alone imagine how in the world science advanced so far as to allow people to see microscopic particles, I guess "it's all about the electrons"!

Rainbow Sripes!

On Day 108, Mr. Bender turned out the lights and we saw some pretty special rainbows! Our spectroscopes allowed us to see what lights were really made up of, and we viewed several different light sources to compare and contrast. Here are a few we saw:

Hydrogen:

Neon:

Natural (Sunlight):

Fluorescent (in the ceiling):

As human beings, we can only see from 400 nanometers to 700 nanometers. Anything after or before that is not visible to the human eye. At first, we had a little difficulty using them, as we did not know exactly know what we were looking for. Mr. Bender cleared that up pretty soon, when he realized some of us were confused. But after that, we started noticing all these random lines and dark spaces....

So what causes the jerky rainbow? These brights lines or stripes are called spectral lines, and they exist because energy in light drops in quantums (discovered by Max Planck ). A quantum is a tiny packet of electric charge and light in an atom. When losing or gaining energy, an atom must gain or lose an entire quantum of energy. And results from each of these jumps or drops in a bright stripe, which we can see! Any jump or drop too high goes into the UV range, and we can't see those.

Who gets credit for doing the work? Well Bohr, a Danish physicist in the 20th century, did a lot of the work. He calculated and did the work involved in figuring out the energies in a quantum, but there is a slight issue: his work was only true for Hydrogen! However, his contribution is still great and he gave us a lot of work with. Bohr said that electrons can only occupy certain orbits at certain energy levels, and that electrons have special "allowed" energies. Energy is only absorbed or emitted to move an electron from one "allowed" energy state to another.

Lights, Lights, Lights!

DHAM There is LAFF! For the last unit of the year :( it sure is bright and sunny! Our introductory day to Unit 7 included a fresh light montage. All classes got to watch Disneyland's Electric Light Parade and learned many cool facts about lights from the bright handouts we received. The two handouts showed us how big of a part EMR (electro-magnetic radiation) takes in our everyday lives. We first reviewed the EMR spectrum, which is in this order from least energy to highest energy:

radio micro infrared red orange yellow green blue indigo violet ultraviolet X-rays Gamma rays
(The higher the energy, the shorter the wavelengths and the higher the frequency)

In addition we were introduced to Nehemiah's Bagel Story, which was about a boy who always carried around a specific number of bagels. However, when given some more bagels, sometimes he would refuse, but other times, he would accept. And then later on, he would drop a specific number of bagels. This story explained how lights worked. Nehemiah was Neon, his bagels symbolized energy, and the pile of bagels dropped represented the spectrums that light emits.

Two days after being first introduced to this unit, Bender-led his first Power Point Lecture in Chemistry Honors class to give us a feel for what AP Chemistry is like. This light lecture was very integrated and taught us much new information. Here's a list of the main points.

• Planck's constant! (E=hv) Max Planck proposed that energy comes in packets called quanta


• Einstein used Quantum Theory to explain the Photoelectric Effect
  
• Bohr - discovered Hydrogen's secret code using Planck's theory; mathematically discovered how to find the wavelenghts of the spectrum we can see for hydrogen
  
• Bohr's main contributions: electrons can only have certain quantum of energy, which are involved in change of energy levels


• Every element has its own spectrum!
  
• Thomas Edison didn't invent the lightbulb! He invented the carbon filament that burned for 40 hrs, and he also improved it to last 1200 hrs in 1880
  
• Incandescent lights - Argon(Ar) and Tungsten(W). Relatively low lifespan because W vaporizes away from filaments, and the filaments then break


• Fluorescent lights - Argon(Ar) and Mercury (Hg). Here's how it works: Ar and Hg gas are excited by electrivity. The electrons calm down and emit UV radiation and some visible light spectrum. Then, the phosphor coating absorbs the UV rays and reemits various parts of the spectrum so that almost all of it is emitted (it's almost white light)



• Incandescent vs. Fluorescent lightbulbs: incandescent - cheaper, safer (no Hg); fluorescent - more energy efficient and isn't 90% heat like incandescent

The response to the Light Lecture was a mixture of reations. Many thought the presentation was interesting and eye-opening to discover things like how EMR plays a tremendously important role in our lives, but I think everyone agrees that it was a very different experience, being taught for the first time through powerpoint. Annie Yau in period 2 said, "The Light Lecture was like an intro to AP Chemistry class, because the whole lecture was powerpoint based, and it was definitely different from what we were used to, but there were some interesting pictures, and it was good practice taking powerpoint notes." Overall, the Light Lecture was a unique and great experience. :)

Favorite Colors of the Unit

WHAT WAS YOUR FAVORITE COLORFUL DEMO AND WHY?

"My favorite colorful demo was the green to pink lemonade or the blowing down the pH scale because it showed the colors of the pH scale and it was pretty colors (:"

"MY FAVORITE ONE WAS THE RAINBOW VOLCANO! unlike the rest of the demos, we were able to see how the colors experienced ALL the different numbers (parts?) of the pH scale. We actually could see what ingredients added would cause what kind of a reaction and how strong/weak bases/acids react."

"I thought all of the demos were about the same to be honest"

"Rainbow volcano because it showed all the colors of the CJ pH scale and it was a good review of unit 6 that we learned so far."

Whether the colorful demos were liked because of the wide variety of colors or because of the cool observations and experiments, Chemistry Honors just isn't the wonderful world of chemistry without them!

Beautiful Hair Day

Want to have beautiful hair? Then consider studying the chemistry.

Acids help dissolve soap scum and smooth hair.
Bases dissolve hair.

That explains why most shampoos are slightly acidic!

Grecian Formula, which re-darkens hair for graying people, is all a chemical change. It produces a pigment similar to melanin (the pigment in skin and hair) that attaches to the proteins in hair, so that, gradually, gray hair becomes darker.

At hair salons, hair dressers use hydrogen perioxide, H2O2, to dye hair. You could technically do a DIY home version, but the perioxide at Walmart won't do you any good! The one Mr. Bender bought was only 3% perioxide ):

I personally found this discussion interesting; As I girl with long hair who gets annoyed by split ends, it was fun to finally learn how shampoo and conditioner worked. Priya Shah, from period 7, also agreed with me, adding "It was fun to learn something applicable to life right now, and nice to learn something other than math related things".

GAH! UNIT 5 Exam!

What day is April 27?
UNIT 5 EXAM DAY!

Right before CST's, the wonderful students of Chemistry Honors took their Unit 5 Exam, which included a 20 minute No Calculator objective portion along with a 25 minute Calculator free response portion. Overall, the entire class did pretty good with the highest score a 42/40. Here are some students' responses to our question
How did YOU do on the last exam?

"I didn't do well on it, but I think that has more to do with the fact that I just got a pHast 40 so I think that was a big factor in how I did. I did feel the test was rushed because I made mistakes that I could have caught granted I had more time to do so. It definitely hurt my grade but it's really my responsibility to fix it, so it's fine." --Sayoni Saha

"I got an A on the last exam. I did worse than I thought because I answered every question and I knew how to do everything, but Mr. Bender's calculator and I did not cooperate well so my answers were wrong even though all my work was right :'( I thought the time and difficulty of the test were okay -- it actually took a lot less time than I expected. Studying definitely paid off. I skimmed through all the CHIPs and I wouldn't have gotten my grade if I didn't do that." --Michelle Chang

"I got a B on the last exam and I guess I didnt study ENOUGH for the exam but i still did so i was kind of disappointed, but all the questions were fair and i was just careless in my mistakes (:" --Priya Shah

"Basically I think I guess I didn’t study that well because I got pretty much a low score. I could have studied more because there were some things I didn’t understand before taking the test. But I thought I did a lot better than what I actually got because I did study a lot…and slept kinda late….i think I just have bad luck or something. I need a placebo." --Anonymous

Though there were mixed reactions to exam scores and feelings of disappointment or content, it seems like everyone does agree on one thing: studying pays off :)

Have a Placebo! It'll make you alllll better.

CRAAAAZY FOR PLACEBOS!

Chemistry Honors first glimpsed placebos in a short clip that included placebos from Mulan (lucky cricket), Kung Fu Panda (secret ingrediant), and Mary Poppins (spoonful of sugar). Later, we watched London from Suite Life on Deck receive a placebo to make her smarter--smartlipstick and smartperfume. We also watched a scene from Family Guy, where the family's anger problems were solved by "mood elevators" (which were, in fact, sugar pills).

So what are placebos?

Placebos are usually sugar or water pills that have absolutely no effect. But because the consumer believes that the placebo will cure them, it actually does. Placebos can also be injections, and even surgeries. They are generally 33%-67% effective.

Fact:
White Pills < Colored Pills
& Pill < Injection
because of how the brain perceives effectiveness.
Isn't it funny how the human mind can trick itself?

Nocebos are placebo's evil twin. They are harmless substances that cause harm because the consumer believes they are harmful. For example, during a study in Japan, a man was given a harmless leaf but was told it was poison ivy. Though the leaf had no effect on him, the man developed a rash!

Placebo: I shall please
Nocebo: I shall harm

We learned that placebos were necessary for the development and testing of new drugs and medicines. And to demonstrate its role, Chemistry Honors even participated in a clinic test!

Using caffeinated and decaffeinated rootbeer, the placebo cpr group was able to collect information on the effectiveness of placebos concerning the relationship between heart rate and caffeine. It was very cool to see it results in person--though I wasn't aware rootbeer even had caffeine in it!

Sayoni Saha in period 7 also told me of her firsthand experience with placebos, in a trial group with medication for behavior improvement in children with Down Syndrome. One mother, whose child had been taking a placebo, was stubbornly insistent on obtaining the "medicine". Though it made for a funny story, it was showed us how powerful a placebo's effect could be.

But now I am a little doubtful. Should I ever participate in a test group, I'm sure I won't see any effects--I'd be too suspicious of being placed in the placebo group!

AMAZING ASPIRIN

What is an aspirin? I can't believe I didn't know one of the most extraordinary medicine until now, even though I've heard about it everywhere. Here's what we learned in Chemistry H. class so far.

What is an aspirin?
-an analgesic agent (pain reliever)
-an antipyretic agent (fewer reducer)
-anti-flammatory agent (inflammation/swelling reducer)
-its active ingredient, salicin, is from willow bark
-too corrosive to be taken by itself, so it's combined with acetylated acid to become acetylsalicylic acid, which is this structure on the right


BUT if aspirin has all these superpowers, why isn't everyone using it everyday?
BECAUSE On top of all these good benefits, aspirin also has its risks and side effects.
-upset stomachs
-nausea
-gastro-intestinal bleeding
-if children who just recovered from chicken pox or the flu take aspirin, they can get Reye's syndrome and die.

Yikes. :/

Still, we learned a lot from this aspirin lesson. Now we know that aspirin isn't some crazy complicated chemical that's too hard for us to actually draw out. "Chemistry is everywhere, even in ordinary everyday things like aspirin," says Priya Shah.

HAHA & BH2OBHOH: Oh yes!

YAAAAAY!

When Mr. Bender first introduced this to us, I was worried. The concept sounded complicated--the acids do what with the hydrogen to how the pH? But when Mr. Bender taught it to us, I was pleasantly surprised. It wasn't difficult at all! As a class, Chemistry Honors was not at all fazed by HAHA and BH2OBHOH.

Sayoni Saha, period 7, found this new information easier to understand than other things we had learned throughout the year. Though she had a little trouble with grasping the concept, after a quick look in the book, she was set to go!

Also in period 7, Priya Shah too found that compared to many of the difficult thing we had had to learn this year, this was by far the easiest to understand. Though it couldn't be classified as "simple", it was very similar to things we had done previously, which made things easier.

Ellie Shin, in period 2, stated that the lesson was "easy".

All it all, I did feel that this was easily understood by most chem students. It was nice to come back from spring break to this, instead of say, something like salts, which was a bit more difficult.

HOT HOT PINK!

Chem Honors went on the 4th Dr. K-pHun COLORFUL DEMO adventure today! I wish I'd remembered to bring my camera today... D;

Here's some important info Bender told us before the demo:
Phenolphthalein turns pink in a solution with [OH^-] > 10^-5 M.

MISSION? Determine whether the following equilibrium reaction is exothermic or endothermic in the forward direction
NH₃(aq) + H₂O(l) <-- --> NH₄⁺(aq) + OH^-(aq)

First we had to prepare a cold beaker with ice and a hot beaker on the hot plate at 80°C. After we added some ammonia, distilled water, and then phenolphthalein indicator into a two test tube, we placed them into the different water baths, and they changed colors to different pinks!

The result? Solution in hot water: light pink. Solution in cold water: hot pink
So is this solution exothermic(heat is reacted) or endothermic(heat is produced)?

If the solution because pinker in cold water, and since we know that OH^- is making the solution pink, we know that the reaction is shifting right to produce more OH^- in the absence of heat. So in the presence of heat, the reaction would shift left, which means heat is on the right, which makes the reaction exothermic! MYSTERY SOLVED!


Overall, "it was nice to actually see the reaction shift left/right, but it was a bit slow and not that colorful," said Michelle Chang. Even though this may not have been that colorful, it was a definite plus that we were able to see the reaction shifting and that we could apply things we previously learned to solve this demo :)

Bleeding Soap

Day 94;

It's the day back from spring break and we're already at Dr. K-pHun's Colorful Demo #3! Here's what happened:

Mr. Bender got soap.
(In period 7, it was soap from Best Western)
He rubbed his hands on it, but nothing happened ):
But then--!
Mr. Bender put water on the soap,
and it began to BLEED!!

So what happened?

There was obviously something going on when the water hit the soap. We know it wasn't just soap and water, because Borah and I did have a bit of a clue: Borah saw Mr. Bender put some clear liquid on his hands before the demo. So whatever it was he put on his hands made the water turn red!

So what was it?

Well we know that water is neutral. Well it's supposed to be, though the tap water in our classroom is less than pure. And we know that soap is basic (we learned that fairly early in the year). Water + soap = basic solution. SO, whatever that liquid was, turned red in bases.

Possible solution: Phenolphthalein?

Phenolphthalein is an indicator, so would change colors in a basic solution. Check!
Phenolphthalein turns red in bases. Check!
Phenolphthalein would be colorless on Mr. Bender's hands. Check!

Mystery solved!