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