Light Spectrum

Additionally. being able to put the different sections of light in the light spectrum in order is crucial to understanding calculations.

The spectrum goes, in order of increasing wavelength and decreasing energy:

Gamma Rays
X-Rays
UV Rays
Visible Light
Infared Rays
MicroWaves
Radio Waves

Here's a visual depiction below:

Identifying Sublevels

The most important fundamental skill for this entire unit is being able to see a periodic table and label it accurately. 

For the unit, the table needs to be labelled into a s, p, d, and f group, as well as the primary energy levels.

On this periodic table here the red represents the s, with 1 orbital and 2 electrons. Yellow represents the p sublevel with 3 orbitals and 6 electrons. The blue represents the d sublevel with 5 orbitals and 10 electrons. Finally, the green represents the f sublevel with 7 orbitals and 14 electrons.

How to Find M of NaOH and M of Actetic Acid

On the test today there were 4 problems involving finding the average NaOH from a titration as well as the average concentration of Acetic Acid. The only problem was that I forgot how to do it. So here I am now making a blog post so that maybe I'll remember it for the final or something.

To find the concentration of NaOH, or the titrant, you take the moles of KHP, and divide it by the volume of NaOH used in the titration in L.

Since our reaction occurred with a 1:1 molar ratio, to find the concentration of acetic acid I just set up a MaVa=MbVb problem. (amount of vinegar)(x)=(M of base)(amount base used)

Unknown Acid Lab

One of the most stressful labs done this unit was the Unknown Acid lab. I think this is partly due to the fact that the power went out in the middle of our titration. 

The procedure for this one was similar to the vinegar and acetic acid lab. We standardized the NaOH and then titrated the unknown acid. The only difference is that this acid dissolved with heat so we used a magnetic stirrer and a hot plate to dissolve the acid. 

Kendall and I ended up getting a 3% error so I am pretty pleased with how this lab went. 

Here are some cool pictures we took during the dissolving of the unknown acid. 

Vinegar Acetic Acid Lab

Over the past few days in class we have been completing the Percent Acetic Acid in Vinegar Lab. As the name suggests, we are finding the concentration of Acetic Acid in commercial vinegar.

To do this, we put an NaOh solution in a buret. Then we measured out .5 g of KOH and added it to 75 mL of water with 3 drops of Pheno. We titrated the NaOh into the KOH solution until it turned pink and recorded how much NaOh was used. 

Then we completed the same titration process with the buret and the NaOh but with a solution of 10mL vinegar and 100 mL water, also with 3 drops of indicator. 

After recording how much NaOh was used, we can now use stoich and molar mass to determine the amount of C2H3O2 in commercial vinegar. 

** you can see the solution start to turn pink.

Resources

This post is simply for me to share some of the resources I have found that are helping me this unit!

• https://www.chem.purdue.edu/gchelp/howtosolveit/Equilibrium/Calculating_pHandpOH.htm

• http://www.chemteam.info/AcidBase/AcidBase.html

• http://www.chemteam.info/AcidBase/pH-Strong-Acid-Base.html

• http://www.chemteam.info/AcidBase/Strong-Weak-AcidBase.html

• http://www.sciencegeek.net/Chemistry/taters/Unit8pH.htm

• http://calculator.tutorvista.com/pH-calculator.html

Converting Using the Ph Grid

Using this grid. you can easily see how we convert from H to OH, OH to pOH, pOH to H, and so on!

Don't know why we do all of this? Well, I'll explain.

When converting from pH to pOH you simply use the equation pOH + pH= 14. This is because the pH scale is 14 and the amount of hydroxide ions you have will always be counterbalanced by the amount of hydronium ions to equal 14.

We convert between H and OH with the natural ionization rate of water over the H or OH concentration to find the amount needed.

The H concentration is 10^-pH because moving up or down by an increment of 1 on the pH scale equals 10 times more acidic or basic of a solution. And that is measured by the H/OH concentration.

I hope those explanations helped you remember why we are using these equations!