Makeup exam for LE1, LE2 and LE3 will be tomorrow, from 2:30 pm onward. Please reply to this post, tweet or PM if you’ll be taking the exam.
3rd T SY 20122013 Final Class Standing of CHM02x
Please comment if there are any discrepancies. I will make a new post for the final grades.
New Projections
Posting this is kind of weird on my part. I don’t know yet what I’ll be dealing with in the future but I really should learn to project what would happen in. Anyway, I am back to 63.46% towards achieving my financial goal for this year and 16.11% towards my DtoE ratio goal until next year. The stock market is looking a little shaky from the past few days but I am not that alarmed since many analysts say that this is just a correction due to the fall of the mining sector. I still have 13 days to go until my official resignation, and 11 days to go until the end of the term. Hopefully, my kids could make it after finals though I am projecting that there will be a lot of casualties. I am not sure how long I should be able to survive without salary since my current employer would hold my last salary and honoraria for at least 1 month. Currently, I am 3.54% behind my previous balance but 1.20% higher than my projection. I hope I could see it through the end of the month with a better balance. I am still hoping to beat my November 2012 balance which is 76.99% towards my financial goal by the end of the trimester.
My projections after this quarter include my salary on my next employment and my budget in Hong Kong. I know things will be a bit shaky for me over the transition and hopefully my next employment will be enjoyable just like my current.
uEdge: Have an Edge from your Competitors
So I got my personal business card yesterday. The design was made by me and I sent this to uEdge for printing. My design incorporates QR codes in my business card for easier scanning to save my details to their smartphone and pointing to my LinkedIn profile in the internet for more information. uEdge also offers the same technology to incorporate on your business cards to make it more cutting edge.
Business Card Printing: Php550.00
Delivery Charge: Php90.00
BDO regioinal deposit charge: Php50.00
Total Cost: Php690.00
3rd Problem Set for CHM02x subjects for SY 20122013 3rd T
A Sigh of Relief
This month went better than expected! I am 27.36% better than my last month’s balance and 24.97% better than my initial projection. All I have to do is to minimize my spending because I am not sure on the coming days on when my salary be held due to my resignation! The stock market has recovered from its decline last Feb 26, 2013 and achieved another record high closing at 6721.45. I am back to 66.39% to achieving my financial goal and 17.64% into my DtoE ratio goal. I know I’m still behind, but I know I could keep it up until the end of the quarter.
Calculator Usage: Two Equations Two Unknowns Problem
This is the part 3 of the calculator post series using my Casio ES991 calculator. This covers how to use the EQN mode of the calculator and using it to find two unknowns simultaneously if you have two equations already. This problem was taken out from Schaum’s Outline for College Chemistry:
Naturally, occurring carbon consists of two isotopes, ^{12}C and ^{13}C. What are the percentage abundances of the two isotopes in a sample of carbon whose atomic weight is 12.01112?
To solve this you must know how to solve for the average atomic weight of an element. The average atomic weight of any element can be computed by summation of the products of the mass of each isotope by its percentage abundance. For example:
It has been found by mass spectrometric analysis that in nature the relative abundances of the various isotopic atoms of silicon are: 92.23% ^{28}Si, 4.67% ^{29}Si, and 3.10% ^{30}Si. Calculate the atomic weight of silicon from this information and from the nuclidic masses.
The solution is just simply: 0.9223(28) + .0467(29) + 0.0310(30) = 28.109 amu. If you add up all the percentage abundances, the sum is 100% or just 1. In our problem, we could say that the abundances of Carbon 12 and Carbon 13 would also add up to 1. So we let x
be the percentage abundance of ^{12}C and y as the percentage abundance of ^{13}C. Therefore, x + y = 1. This will be our equation 1. Equation 2 will come from: x(12) + y(13) = 12.01112.
To solve for the percentage abundances, press MODE à 5 [EQN] à 1 [anx + bny = cn].
Where an, bn and cn are coefficients of your equations. Let me rewrite my equations below as:
1x + 1y = 1
12x + 13y = 12.01112
Input as follows:
a 
b 
c 

1 
1 
1 
1 
2 
12 
13 
12.01112 
Then press enter. The answer should be:
x = 0.98888
y = 0.01112
or 98.89% and 1.11% for ^{12}C and ^{13}C respectively.
Now try:
35Cl and 37Cl are the only naturally occurring chlorine isotopes. What percentage distribution account for the atomic weight, 35.453? Your answer should be 77.35% for ^{35}C and 22.65% for ^{37}C.
Just Asking…
Hi guys, would just want to ask something. Since I won’t be teaching anymore next term, if ever I would offer free small courses in the internet (i.e. electronic structure of the atom), would you enroll? Please hit the comments section or click here…
Using Linear Interpolation
Most students don’t know how to use their own calculator. It is my belief that the calculator is only as good as its user (well, it applies to every gadget: cellphones, laptops, etc.)! Anyway, here’s how you could use your calculator to interpolate.