lan418

I'm going to attend university of florida this fall. I have taken AP chemistry and i was wondering how fast the class moves and how different it is from what you cover in AP chem. I guess im just worried that i might take the class for an easy class and end up being overwhelm by the unanticipated course. Same questions with the labs with the course.

yea, i cant moisten my hands, too big of a risk when playing Don juan

I see what you mean lan418' date=' but I think you missed my point. The reason why I think a [b']tutorial forum [/b] would be better than the homework help forum is because it's not a one on one thing where one person has to spend hours explaining a whole section of science to one other person.

 

In the new forum, a person starts a thread on the topic they want to share (e.g. organic nomenclature), others can input more indepth info. So now if a person is having trouble with organic equations, he/she can come to SFN and read the lesson and learn. It's not like you are doing the homework for people where they ask a question and you answer it, it's more like an online SFN encyclopedia for students as a reference.

But why do that if you have online references? Chances are, what we post may not cover as much as other websites has already posted.

That would be great.

 

I also noticed that not many people post replies in the homework help forum' date=' maybe the questions are too difficult, or people just don't want to spend a lot of time explaining to one person on a whole section of science. I think we could have a [b']tutorial forum[/b], basically anyone who feels confident can start a lesson (teaching others about a specific science topic) this way others can learn new things without resorting to textbooks. People could make comments or add new info to the lesson. By the end we might be able to have our own SFN encyclopedia, this will attract more people to do their projects, homework, research at SFN.

 

I mean science forums shouldn't be just about expressing thoughts and opinions, it's also about sharing knowledge with others. (I know we learn things through conversations, but it would be so easy to just go to the forum, find the topic that you want to learn, and read+study+chat+have your homework done without the desperate waiting in the homework help forum.)

 

We can even divide the forum into grades (from grade 7 to the end university), areas of science etc. This way no one would feel embarrassed when trying to ask/find out info on a lower science level.

the only thing we have to worry about is how this whole thing will produce indolence among students. It's ok to have a second, more casual, reference concerning science but what happens if the forum becomes a subsitute for textbooks? pretty soon, the "teachers" will end up explaining every general detail that should of been known. I don't think most people on this forum can afford that kind of time on their hands. Im just skeptical of those who want to get their homework done as fast as possible. If they were out of the pic, then by all means, im for it.

Why, physiologically, does dipping and drowning your hands in hot/warm water before a piano recital/performance allow better flexibility, agility, and endurance for your fingers?

I've played a piano concert with and without doing this and noticed an increased performance when i dipped my hands in hot/warm water. Certain passages i played energetically with less fatigue while without warm water my fingers weaken and start to tired. My guess is that it has to do with increase blood flow making muscles more responsive and active through your muscular tissues.

yea, and it just depends on how you look at things. Trust and insecurity are main psychological reasons of jealousy.

It's better to talk about your jealousy than trying to win it with a pill anyways. What is making you jealous if you dont mind me asking

your absolutely right, i did not have one clue what you did. (although i did kind of with your explanations but first time coming across it for me). But if you asked me to do it your way again, i would be confused. i guess this can be exposure for future reference?

Well, mediculous you got the right answer. Your work came out to the right value. However, the teacher just did it with 2 simple steps. 1) find the limiting reageant. 2) use the limiter to the ratio of C using stiochiometry and eventually the units cancels out and you end up with .18 mol. heh, the teacher went up to me and said i confused the heck out of him. but thanks for the help.

heh, tommorrow, but i posted this topic a few days ago. so i didnt wait till the last minute at least

What is wrong? this assignment is a heavy burden on my grade : (

yea sure, thanks for the help

lol nah. just a problem from a general chem class assignment. There were actually 4 parts to this question but i didnt bother to put them since i didnt think that they were relevent to the last part the question was asking.

Mediculous, i dont understand how the alegbra works for this problem when you plug it in. what does dt and -d denote? Can you show it out for me please?

i'm sry, i did get your answer. Must of read the wrong thing

Oh, maybe i did something wrong? for the constant i got around 69.6.... but my major concern is the consumption, i dont see how you would solve for the final Molar concentration of C.

anyone?

A(aq) + 2B(aq) ---> 3C (aq) + D (aq)

For the reaction above, carried out in solution at 30deg C, the following kinetic data were obtained:

Experiment Int. concentration of reactants mol/L

Ao Bo

1 .24 .48

2 .24 .12

3 .36 .24

4 .12 .12

5 .24 .06

6 .140 1.35

Int. rate of reaction mol/L * Hours

8

2

9

.5

1

?

Assume that the reaction goes to completion. Under the conditions specified for experiment 2, what would be the final molar concentration of C?

How do you find it? what does it mean when it goes into completion? does it mean that all is consumed?

The solubility of iron (II) hydroxide, Fe(OH)2, is 1.43E-3 grams per liter at 25 deg C.

a) Write the balanced equation for the solubility equilibrium.

My answer: Fe(OH)2 <----> Fe [2+] + 2 OH -

b)Write the expression for the solubility product constant, Ksp, and calculate its value.

My answer: 1.61 E - 14

c) Calculate the pH of the saturated solution of Fe(OH)2 at 25 deg C.

My answer: pH = 9.5

d) a 50.0 mL sample of 3.00 E -3 molar FeSO4 solution is added to a 50.0 mL of 4.00 E-6 molar NaOH solution. Does a precipitate of Fe(OH)2 form? explain and show calculations to support your answer.

i got to the point where no precipitate will form.

2. The acid ionization constant, Ka, for propanoic acid, C2H5COOH, is 1.3 E-5.

a) calculate the hydrogen ion concentration, [H+], in a .20-molar solution of propanoic acid.

My answer: [H+] = 1.6 E -3

b) Calculate the percentage of propanioc acid molecules that are ionized in the solution in a.

My answer: .8 %

c)what is the ratio of the concentration of the propanoate ion, C2H5COO- , to that of propanioc acid in a buffered solition with a pH of 5.20?

My answer: .49 for the ratio

d) In a 100 mL sample of a different buffer solution, the propanioc acid concentration is .50-molar and the sodium propanoate concentration is .50 molar. To this buffer solution, .0040 mole of solid NaOH is added. Calculate the pH of the resulting solution.

My answer: I am not very sure about this, i got final pH of 4.96

Problem:

Use simple structure and bonding models to account for each of the following.

a) the bond length between the two carbon atoms is shorter in C2H4 than in C2H6.

b) The H - N - H bond angle is 107.5 degrees in NH3.

c) The bond lengths in SO3 are all identical and are shorter than a sulfur-oxygen single bond.

D) The I [3-] ion is linear. Note: the brackets [] indicate the ionic charge.

How do i approach this? i dont understand what they want, the molecular geometry ? the shape?