bleach-analysis-analysis-questions
See this powerpoint as a guide to your calculations and which discussion questions you should answer. Remember to restate the question OR write out the question before answering. Label your calculations and don’t forget to include your calculation of your titrant (sodium thiosulfate).
Welcome back students. This year, since I have a new baby :), I will be working in the mornings first and second periods. I now teach AP Chemistry and Applied Chemistry on Black days and Physics I and have prep period on Gold days. It is such a blessing to be at school with you for part of the day and home with Gunnar for the other part.
I have also made a few changes to the classroom policies so stay tuned for those to be posted shortly. If you are in Physics, just a reminder your lab rules sheet is due Thursday (8/21) and your composition books are due Monday (8/25). Chemistry classes, your lab rules and Composition books are due Friday.
It has been a good start to school and I look forward to getting to know you all better and having a little fun… oh yeah, and learning too!
If you are new to the site, just a few things you should know. To the right, you will find links that help you view posts that are specific to your area. Further down the sidebar, you will find links to websites I use often and think you might enjoy checking out, or that are just plain fun. Finally, you can look in the archives for previous posts. You can comment on posts and ask questions. They will not show up until you are approved, and I will take care of that. Give it a try.
Seniors, if you would like to to know your exemption status, the names of those exempt according to grades earned in my class has been submitted to the office for an attendance check. If you just can’t wait to find out from them, send email to bergerj@delphi.k12.in.us with the subject line “AM I EXEMPT?” and I will let you know. That way, if you have any questions about your status, we can deal with them in a timely manner. I realize some of you have some work you are doing with Mr. Thompson, and this will be included in your final grade, but is not eligible for exemption status as of now because those names had to be turned in today. You will get credit for the work you have done. If you are not exempt, material from second semester is fair game for your finals and review sheets will be posted here soon for each class.
So Torie commented on another post but I thought this deserved its own post. Here is what she said:
I am confused on the lab with the Mg and HCl.
I got all of the calculations except for the ln [H3O]+. I dont know how to figure that out…and then the part after that… ln rate= m ln[H3O+] + ln k
I am not sure what to do with that…
[H3O+] is the concentration of H+ or H3O+(same as H+ except it has water attached) in solution. Since HCl is a monoprotic strong acid, when placed in water, HCl ionizes into H+ and Cl-. If you have 0.25M HCl, the concentration of H+ in solution will be 0.25M because there is a one to one mole ratio. So, when they ask for ln[H+], just calculate the natural log of the concentration of your acid. Since slope-intercept form is y=mx+b, if you plot natural log of rate on the y axis and ln of concentration on the x axis, your y intercept will be the natural log of the rate constant. This is useful if you want to find out what your rate constant is. YOu can get the point-slope equation by adding a trendline to your data in Excel and in the extra options, show the equation. See me in the morning if you still have a question.
Helpful websites:
Georgia Southern’s website with pictures from class and other tutorials for VSEPR and polarity (good for quest review)
Basically, you want to know how the properties of gases affect each other, what makes gases special from other phases of matter, the differences of the ideal gases and real gases, how to use ALL your equations and what the variables stand for (the appropriate R values for each), how to convert from one unit to another, whenever you used temp. it should be in Kelvins, gas law stoichiometry, mole fraction and partial pressures, the postulates of the KMT, diffusion and effusion. You will be given equations and constants.
If you are working on your Chapter 5 Independent Study, please post questions to this topic. Kylee asked the following:
I started on the problems and i understand the pressure stuff in the first section but i don’t understand the unit stuff for problems 27 and 29. Its the exact same type of problem so i’m guessing i kinda need to know what I’m doing. I know the equation to use is P(gas)=P(atm) +( or -) h. But since h is in m or cm and P(atm) is in (atm, torr, Pa, etc.) how do you do that?
One thing that will help you is that the unit of Torr is the same as millimeters of mercury, noted as mm Hg. On the weather reports on TV, they report this in inches of mercury because the average Americans a) don’t know what a millimeter is and b) don’t much care what the atmospheric pressure is. Anyways, mm Hg is the same as a Torr so when 1 atm equals 760 Torr, this is also 1 atm = 760 mm Hg. If your height is given in meters or centimeters, just use your metric conversion expertise and move the decimal. Also, a few other tips:
Good luck! I hope you are all having a great break and are enjoying the snow!
Chemistry I and Physics will take their finals on Monday, Dec. 17.
Chem I Review List – Chapter 5 Test Questions for Review
Applied Chemistry and AP Chemistry will take their finals on Tuesday, Dec. 18.
AP Chemistry Review List
Eventhough most of you weren’t in class, I didn’t want you to miss out. Here’s the rundown:
HW #12: pg 870 #56, 59-60, 63-64, 67-68
Be sure to have read over and know your lab for Friday.
You will also be responsible for the concepts in the remainder of Chapter 17. Specifically pay attention to corrosion of iron and how to prevent it, how an electrolytic cell is different from a voltaic cell, how electrolytic cells are used commercially, and other types of cells. We will try to finish up Chapter 17 on Tuesday and review what we can. Our test over Chapter 17 will be Thursday, Nov 8.
Check out these sites to help you understand Chapter 17!
http://www.ausetute.com.au/voltcell.html – This is really good!
http://www.blackgold.ab.ca/ict/Division4/Science/Div.%204/Voltaic%20Cells/Voltaic.htm – Super animation link on this site!
http://en.wikipedia.org/wiki/Galvanic_cell
http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch20/electro.php#voltaic
Mrs. Berger's Chemistry and Physics Blog 