Air Bag Lab

This lab was very cool! Figuring it all out with the calculations was a little tough, but it helped to have some other people help me out in the process. I knew we had to take into account of 5% acetic acid in the vinegar but I didn't know what. I feel so dumb now because you needed to multiply it by 20 to get 100% acetic acid. After passing the pre-lab and all showing Frank our calculations we all picked the biggest bag possible. It was funny because we all had these huge plastic bags. It certainly made calculation easier since we would all have the same volume. The bag turned out to be 3.733 L. That's a lot! At first we were just going to fill the bag 85% full, but we switched it to be 90% full which worked out great! We put about 11.3 g of baking soda and 200ml of vinegar in the bag and shook it all up together with the bag sealed shut. It was scary but cool at the same time to see all the bubbles form and feel the CO2 building up in the bag. I was almost afraid mine was about to explode. But it was all good! I passed the lab! I had successfully made an air bag!

Avogadro's Law

Avogadro's Law:
Tells us that for a gas at constant temperature and pressure, the volume is directly proportional to the number of moles of gas present.

Equal volumes of gases at the same temperature and pressure have the same number of particles. This relationship hold true for gases at low temperatures.

As the number of moles of a gas to increase, the volume will have to increase in order for the pressure of the system to remain constant.

The volume of 1 mole of gas (at STP) is 22.4 L

Avogadro's Law
Avogadro's Law

Charles' Law

Charles' Law:
Tells us that temperature and volume vary directly with each other. This holds true at constant pressure. As temperature increases = volume increases.

Temperature must be in Kelvin which is 273.15 K. So degree C + 273.15 = _______

As the temperature of a gas increases, it gains energy. This will result in an increase in contacting the sides of their containers -- they are going to want to expand. Keep in mind, Charles Law holds true at constant pressure. If the pressure is going to stay the same, the system has no choice but to allow for the gas to expand --resulting in an increase in the volume of the gas.

If Charles Law is extrapolated backwards, where volume = 0, the value of absolute 0 can be achieved. We call this -273.15 degrees Celsius (Kelvin can't be negative!!!!), absolute zero. There is no kinetic movement of molecules at all.

Charles' Law
Charles's Law

Gas Laws

Characteristics of Gases:
Gases expand to fill their container (no definite volume)
Gases are highly compressible
Gases form homogeneous mixtures
Gas molecules are relatively far apart from one another and exert little influence on each other (collisions are elastic)

You can measure pressure by using a barometer.

The ideal gas is at 1 atm and 0 degrees Celsius or 273.15 degrees Kelvin

Four factors which determine the state of a gas are:
-pressure
-temperature
-volume
-amount in moles

Boyle's Law:
Boyle's law doesn't boil! Temperature is held constant!
It tells us that the relationship between pressure and volume is an inverse relationship.
As we increase the volume of the container, there are fewer collisions with the sides, so we interpret that as a decrease in pressure. As volume increases = pressure decreases.

The Sci Guys: Science at Home - SE2 - EP9: Boyle's Law of Ideal Gases
Boyle's Law

Helpful Links!

Just some helpful links below!

Phase Changes
Phase Changes and Energy
Phase Changes
Chemistry Lecture: Phase Transitions and Phase Diagrams
Chemistry Lecture: Phase Diagrams
Calculations involving heat and specific heat

Basics of Energy

This was a fairly easy unit in all honesty. We learned that thermodynamics is the study of energy transformations. Also we learned that energy is defined as the ability to do work which is a force applied over distance. However work can also be defined as directed energy change resulting from a process. There is kinetic energy, which is the energy of motion, and potential energy, which is stored energy,

We define temperature as a measure of the average kinetic energy of the particles of a substance. We also measure the flow of energy through endothermic and exothermic reactions. Endothermic is when the system gains energy, or takes in energy, from the surroundings. Exothermic is when the system loses energy, or gives away energy, to the surroundings.

We measure energy in Joules (J) and also in calories (c). The conversion is 4.184 Joules in one calorie.

When calculating heat we use the formula Q= mc (change/delta)T
Q is heat in Joules
m is mass in grams
c is specific heat in (J/g degree C)
change/delta T is change in temperature

Boat Races!!!

Man oh man was this a stressful, yet fun, project! My partner and I had to design a boat that would float, not turn into a flaming ball of fire, and be light enough for our putt-putt engine to push it across the gutter using our biodiesel and a candle wick as the fuel. I'm glad my partner was in engineering because I wouldn't know where to start! He came up with a good design to use a milk carton as a boat. We made tons of modifications to the boat the first day of testing but our engine kind of let us down. 2 days later the day of the race we had a different boat that was a little shorter with the engine lower. Our little boat made it across at record time of 55 seconds! Our boat may have been the slowest in our class but in my heart it was the fastest! Slow and steady wins the race! It was cool that we used actual fuel to burn the candle wick to make our boat go. It was a fun project with some stress added to it because getting it across the gutter was a trouble the first day of testing our boat. But we made it!

Here's our cute little boat!

Making of Biodiesel in the lab!

The morning of the making biodiesel was a very stinky morning! I brought a change of shirt so I wouldn't smell so bad later on in the day from the restaurant oil, but I could still smell the oil throughout the day! I thought it was really cool that we could make our own biodiesel. What's so cool about it is that it only look about 50mins to make honestly. 50mins is all it takes to save the environment. It's quick and easy. Plus imagine all the excess oil from all the restaurants! We can reuse it for fuel! This project really turned me into a huge tree huger to be honest. Yes it was a stinky lab but it was really cool to make something that a car could run on! I think it's super cool! The oil kinda looked like syrup and it was really gross but cool at the same time! What freaked me out though was that the second ingredient (that I forgot the name of...maybe glycerin??) could eat your flesh if it stayed on there longer enough. But hey everyone survived the lab!

Here are some pictures below of our biodiesel!

Making of Biodiesel commercial

I had no clue what biodiesel was at the beginning of this project. But after some research for our commerical project, I really think everyone should use it. It's home grown so we don't have to keep going to foreign countries to get our oil. It's also a renewable source! It decreases green house gasses by 86%! Imagine what the environment would be like if we all switched to biodiesel. The Earth would certainly look healthier and greener! This making of the video really opened my eyes to how badly we treat the environment. I loved this project and I really wish we could do another thing like this but sadly the end of the year is coming to an end. I can't wait to see what next years chemistry students will come up with!

Here's our video below!
Biodiesel: Make the Environment Great Again!

Here are some other video's from our class and from other schools that I thought were really good!
The Misconceptions of Biodiesel
Tom the Trucker Uses Biodiesel
Chem Biodiesel Project
BioCat vs Fossil FuelHog
Biodiesel: The Key To A Sustainable Future
What is Biodiesel?
Biodiesel: Fuel for All!

Bond Polarity

I understood this on the Friday we learned it. However the following week after my brain seemed to just dump it out and made me forget all of it! I had to relearn it again. I think the second time made more sense however. It kinda confused me when the bond itself can be polar because of imbalance of charge and when one atom is more electronegative than the other and then the molecule itself is nonpolar. The trick is to look at the shape since shape determines function. If the bonds are all pointing away from each other they basically cancel out since no one atom sucks the electrons (partial negative - most electronegative atom). Also you have to remember if the shape is polar or nonpolar in general. It got confusing to me no doubt but I finally got it later on. It's a lot to handle that's for sure! But once you have that click it'll all make sense!

Helpful Links! 

Polarity

Bond Polarity and Electronegativity

Second Lecture

The second lecture had me all confused. Resonance and shapes of molecules and electron geometry. Man that was some pretty confusing stuff I'll tell yah! It took me awhile to get but I finally understood it. The shape is just how many bonded entities there are and pay attention to lone pairs. The electron geometry is just where the electrons are found. If you have two bonds and two electron lone pairs the electron geometry is tetrahedral. It took me a bit to piece it all together but I finally got the click and everything came together! Also the online practice tests helped out a lot in helping me understand all of the things we learned. Resonance tripped me up the most though. When we added polar and nonpolar it frazzled my brain as well! No lone pairs=nonpolar. Nonpolar is symmetrical. Polar is just the unsymmetrical shapes with lone pairs. Only polar shapes are trigonal pyramidal and bent molecules.

Above is Resonance 

Helpful Links!

Sigma and Pi Bonds: Hybridization Explained!

Bonding-polar vs nonpolar molecules -keeping it simple

How To Tell if a Bond is Polar or Nonpolar (the super easy way)

Bonding Models and Lewis Structures: Crash Course Chemistry #24

Chemical Bonding

So at first I semi understood the first lecture. It made sense but once I got to the Lewis Dot Structure with have need share and formal charge I got a little confused. But I quickly understood it better when we had that lab in the library. It was fun to draw on the tables! Plus it was good to have models as well and visually see the molecule. Working in groups helped me too. We all collaborated and helped one another out. I hope sometime in the future we can do that again!

Helpful Links!

These links helped me for studying for the test! I would strongly recommend reviewing these over! These are for visual people (or anyone in general but it helps visual people) that need to see how everything works. These videos are kinda long but trust me they are worth it. They go in depth! I hope this helps all y'all!

Group trend for ionization energy
Period trend for ionization energy
First and second ionization energy
Electron affinity
Electronegativity
Metallic nature

Periodic Trends

Today in class we learned about periodic trends. I understand about 3/4 of it. I'm kinda worried because the test is on Thursday and I'm not fully understanding this. I get that atoms get bigger from top to bottom and right to left. I understand that ionization energy is greater from left to right. But the other one I don't get. I get that atoms get smaller or bigger by that if they lose or gain electrons but I don't get the other energy about gaining electrons and how it's gains energy left to right when non metals don't need much energy to accept electrons since they automatically do. I get it takes more energy for ionization for non metals to give away electrons since they normally don't do that. I don't know I'm just very confused right now.

Quiz in Chem!

As we all know the morning of the quiz is always stressful. Everyone is in the classroom repeating stuff over and over to make sure they have it down. I was practicing writing everything down correctly on my periodic table. I actually did pretty well on the quiz because of that and instantly writing all the formulas down once I got the quiz. I advise everyone to take 5 mins before the quiz and look at formulas and practice writing them down. Then once the quiz comes write it all down so it's fresh in your mind and you won't have to worry about remembering all of it. It's helped me! I studied my butt off for the quiz and it payed off because I got an A which was what I was hoping for!! Practice makes perfect!

Electron configuration

I was so angry at the school for doing a freaking fire drill in first hour when we had a FULL lecture day!!! Absolutely terrible. To top it off I wasn't quite understanding what electron configuration really was. But later I got a hold of it. Honestly this stuff is pretty tricky. I mean it's easy to find an element and just follow along the s, d, p, and f blocks. But the first day I learned all of it was stumped. It takes practice and time to learn. Most of all it takes patience! I'm just glad that the exceptions are pretty easy and they are basically in the same family or group and there r only six of them we have to know. But drawing the electron configuration did confuse me! But thankfully I got everything down!

Wavelength

At first I was really confused about wavelength and how to calculate it and add the equation for energy. I was honestly a mess. But I did a lot of the practice problems and I learned it quickly. Now that I look back at it, I just laugh at how silly I was for not getting it at first because it's pretty basic for the most part. In a way I think it's pretty cool that we can measure wavelengths or frequency or energy of a wave that we can't even see!! We can do all these things with chemistry! I think that's pretty cool! I can go up to someone who's wearing a red shirt and say hey ur shirt is giving off 7.0 x 10-7 meters in wavelength and is  4.3 x 10 E14 Hz. That's pretty freaking awesome!

Flame Test Lab

I thought this lab was amazing! I learned a lot about how metals can give off certain colors that can be used in fireworks! The flame test was the coolest lab because we got to deal with fire while learning about which metal burns what flame color. My favorite was Lithium because of the nice red color! The copper green was pretty cool looking too! I thought it was specially fun to have an unknown so we could guess the metal used. It really put knowledge and fun all into one lab! 

Test Day

So I can say for myself that I know I didn't do too well. I studied as hard as I could this past week and doing all these problems. However from Sunday night to Thursday morning I have about 10hrs of sleep in total. So I think my problem wasn't I didn't know the material but that I was sleep deprived therefore I couldn't remember anything well. Welp, better luck next time for me!

Titration Lab

I swore this lab was the death of me buttttttt I absolutely loved the lab!!! Probably just as fun as the Copper II Chloride lab! It's just this lab was about accuracy and precision (which I love!) but I just got stressed out because any little mess up or wrong measurement even by the 0.001 or not making sure the meniscus is exactly at zero before titatring can make your percent error increase. Yes it was stressful but I learned a lot in this lab. I learned how even one little drop of NaOH can make a faint pink solution to a bright fusia color that was really pretty. I learned how titration works by using a buret. I also learned that desks come in handy when you're too short to read the meniscus straight on and accurately!

Some pictures of the lab below! 

Acid Mystery Lab

This lab was on Monday and Tuesday of this week. It's basically like the previous lab we did but this time the acid is a solid. All in all this lab was just as tedious as the last one by that you need to be as precise as possible with all of your measurements. I loved this lab! Yes it's tedious and challenging but I'll take that lab over some silly lab even a 8 yr old could do. These labs help me learn so much and help me understand what we're doing in our lessons. It's putting the knowledge I was just taught and putting it into a real world example. I'm more of a hands on person in order for me to learn. I just learn better when I'm actually applying my skills. I hope we keep doing more labs like this because I've learned a lot about how acids and bases work in titration!

Quiz!

So the night before the quiz I made sure I knew everything by heart. Took a little bit, but it paid off in the long run! Yes Monday quizzes/tests are terrible just because it's on a Monday and Monday's are terrible in general. But I was glad it was on Monday because it gave me time to study all the practice problems in the packets. I was a little worried about the ICE Box questions just because there wasn't any practice problems in the packets. However I think it's fairly easy enough. I thought it was kind of funny how that day in chem (on Friday) we learned about using the quadratic equation in ICE Box questions and the same day in math analysis we relearned it in class! Funny how things work out! But all in all I felt confident about the quiz. If anyone needs help understanding anything, I'm open for questions!

Finding pH and pOH

Just some key notes here:
Remember the H+ is used to tell if a solution is acidic or basic. Low concentration of H+ means that the solution has a high pH (basic). However the higher the concentration of H+ means that the solution has a low pH which is considered acidic.

# of sig figs in concentration = # of decimal places for pH

At first I was confused how to get from concentration of H+ to pOH. In all honesty if you know the box chart you can do it on the top of your head. My tip for my fellow blog followers is to do TONS of practice problems with it. It helped me a lot!

Helpful Links Below!
Finding pH and pOH
Calculating pH & pOH, [H+], [OH-], Acids & Bases CLEAR & SIMPLE Video
Practice Problems

Intro to Acids and Bases

I would say the part I first struggled with in this unit is the difference between Arrhenius acids/bases versus Bronsted-Lowry acids/bases. Here's the difference!

Arrhenius acids: produces H+ ions in aqueous solutions   

Arrhenius bases: produces OH- ions in aqueous solutions 

Bronsted-Lowry acids: proton (H+) donor

Bronsted-Lowry  bases: proton (H+) acceptor

Key note: Bronsted-Lowry acids/bases are the ONLY ones with conjugate acid/base pairs 

Acids produces conjugate bases and bases produce conjugate acids. 

This basically means that when you have an acid that gives up a proton (H+) the conjugate base is just the remaining substance when a proton is lost from an acid. The conjugate acid of the base is the substance frmed when a proton is added to a base, 

Some important key notes:

-Water is amphoteric substance meaning it can act as an acid or a base. 

-Group 2 metals liberate twice as much OH- for bases 

-Strong acids/bases will have weak conjugate acids/bases

Helpful Links!

Acids and Bases Khan Academy 

Arrhenius acids and bases

Bronsted-Lowry acids and bases theory  

STOICH IS BACK!!!!!

I absolutley love stoichiometry! I think it's really easy and fun to do. Plus when I tell people I think Stoichiometry is easy I sound like a fancy smart chemist! ;) A lot of people think that just by hearing the name it'll be hard, but honestly it's pretty simple. So when we had the lesson about using Molarities in Stoich calculations I was pretty happy! The examples we did in class make sense to me. The only thing that trips me up is using liters/mL all the time. I just need some more practice with these types of problems. But what I love about stoich is that the steps to solve the problems are all the same. It hardly changes. It's the same basic flow. 

Here are the steps to solve problems using molarities in stoich calculations:
#1 Write balanced equation
#2 Calculate moles of reactants
#3 Find limiting reactant 
#4 Calculate moles of other reactant or products
#5 Convert to grams or other units if needed.  

Not too shabby! ;) 

Here's a little tip!! 
If the problem gives you 4 bits of info (2 info for each chemical) then you are going to find the limiting reactant. 

If the problem gives you 3 bits of info (2 about one chemical and one about the other) then you are just going to use plain stoich (not finding limiting reactant). 

Helpful Links Below!
Molarity Problems and Examples
Molarity with Stoichiometry
Molarity with Stoichiometry involving Limiting Reactants
Review of Stoichiometry - using Molarity

Murder Investigation

This lab was a little tough to say the least. At first when I got the lab, all I could think of was how stupid am I not to figure any of this out. I was honestly completely lost. But then I had that click. That click put everything into place! I figured out how to get the answer, the procedure, and the final calculations because of that one click. It was a chemistry break through for me! I think 2 weeks of not doing chem kind of made me stupid when we first got back because I couldn't understand anything. This lab was going to be the death of me because I was just so stuck. I couldn't figure out what to do. But the night before the lab I was super excited for it! I knew exactly what to do and I felt pretty proud! I just needed to get back into the norm of things in chem! All in all, I thought the lab was a good challenge. It was actually fun trying to figure out who killed Ms. Scarlet! :) I hope we do more labs like this in the future! 

Dilution

Definition: the action of making something weaker in force, content, or value.

Formula: 
M1V1 = M2V2 

M= molarity 
V= volume 

The M1V1 is also known as stock which should have the higher concentration since it is your beginning solution. 

Serial Dilutions are successive dilutions in a row.

At first I didn't understand what dilution was really. However, after the lab and physically diluting a solution helped me understand better. It's basically taking the solvent in equal amounts and adding a little bit of the concentration from the previous cup/solution into a cup. It just decreases the amount of concentration of the solute. It's kind of like having a city with tons of people inside it and the people are atoms of the solute. But then it gets too crowded and people start moving to suburban areas (less crowded). Then finally some people move from suburban to rural ares where there isn't many people (atoms). That's kind how I think of it. 

Helpful Links Below! 
Dilution Problems
Dilution Practice
Dilution Practice Problems