delco714

THIS MAKES NO SENSE. IT's like starting at Latin.. actually, latin makes more sense... does anyone know about molality, and figuring out all the different stuff, like the mole, and molar mass for this given question?: A 0.517-g sample of a nonvolatile solid solute dissolves in 15.0 g of t-butanol. The freezing point of the solution is 22.7ºC. a. What is the molality of the solute in the solution b, Calculate the molar mass of the solute. (BTW: t-butanol>> Freezing point = 25.5 C, Kf = ( (C*kg) / mole) = 9.1) If you can explain how you do it... pleeeassee. I have no idea how to do this.. The lab book doesn't tell us how, it just throws us numbers and questions. This is an important inorg. chem concept and I do want to learn how to do it!!

you bet your ass it does Phi.. try like.. 58 hours of studying in 4 days... 3 tests.. in last 5 days i accumulated on average 4.5hr sleep a night.. but i got a 93 on a chem test where avg was 58.. a 96 on bio, avg 75... and a psych course (don't even ask.. prof is a PSYCHO bit<h)... otherwise.. yes.. hopefully i don't burn out.. thennnn over the winter break.. I'm going into Manhattan to take a phlebotomy (blood taking, and lab analysis regarding blood) course for 3 nights week, 3 weeks. Than another semester... a year from now I will have organic chem, physics.. two advanced psych courses and calc I. (i'm pre-med and a psych major..).. and after THAT semester, i have the same schedule, minus the calc, and add MCAT prep course... it's a long road ahead my friends..

The question isssss...: A mixture of gases collected over water at 14ºC has a total pressure of 0.981 atm and occupies 55 mL. How many grams of water escaped into the vapor state? now at 14 C, water has a pressure of 12 torr, or 0.01279 atm. I did the ideal gas law equation for no (moles), using 0.981 atm, which came to be 0.0023 mole, if we X that by water's weight (18.01528 g/mole), it is 0.0413g. But this isn't right.. where is my mistake?. i Know that the pressure of water ^^^ has to be used somewhere, but I don't know how/where... dont worry about it, i got it. thanks anyway, i guess it was too hard for you to figure out.

The question is: Oxalic acid, H2C2O4•2H2O (molar mass = 126.07 g/mol) is often used as a primary standard for the standardization of a NaOH solution. If 0.147 g of oxalic acid dihydrate is neutralized by 23.64 mL of a NaOH solution, what is the molar concentration of the NaOH solution? Oxalic acid is a diprotic acid. (Hint: what is the balanced equation?) My calculations (which the lab site said were wrong) are as follows: 0.147g/126.07g/mole - 0.001 mole (oxalic acid) M (moles/Liter) = (0.001 mole / 0.02364 L) X (2 mole NaOH / 1 mole acid) = 0.085 mole/Liter NaOH. is this right and I should disregard the site, or where did I mistake?

but... MOLE / (MOLE/L) = x Liters...which is 0.00997 L.. which does = 9.97 mL... did you mean Liters and mistakenly put mole?

Lemon juice has a pH of about 2.5. Assuming that the acidity of lemon juice is due solely to citric acid, that citric acid is a monoprotic acid, and that the density of lemon juice is 1.0 g/mL, then the citric acid concentration calculates to 0.5% by mass. Estimate the volume of 0.0100 M NaOH required to neutralize a 3.71-g sample of lemon juice. The molar mass of citric acid is 190.12 g/mol. ANSWER IN ml of 0.0100 M NaOH. i did: 3.71g X 0.005 = 0.0186 g citric acid 0.0186g / (190.12g/mole) = 0.0000977 mole 0.0000977 mole X 39.997 g/mole NaOH = 0.00391g NaOH V = 0.00391 / 0.0100 M = .39008 L NaOH = 390.08 mL NaOH says it's wrong..

Stupid question but when we are heating up CaCO3, we get CaO and CO2 right? But what happens when it doesn't fully decomp completely? I'm figuring the ratio of CaO and CO2 is 1:1, but how would the mole ratio change if it doesn't fully decomp? Also.. if the CaCO3 was contaminated by a thermally stable compound, how would this affect the decomp and ratio? Thanks for the help!

thanks blike, good comment... PS. look at my above post!! -Steve ..and blazarwolf, you put much into perspective. well said.

Volunteer work?.. Like working as a volunteer of an ER of one of the more prestigous Hospitals in NY (not to mention teaching Hospitals).. and volunteering in the Deprtment of Neurology at the school i want to attend?.. and.. i have to work part-time.. but I'm sure i can crunch 36hrs into my 24hr day. Does the fact that my mom has MS and me saying that have any weigh n the fact that I chose to become a DR.. that I want to help people just like her or worse.. and not only progressive MS patients, but one's with spasticity, and patients with Alzheimer's and other dementias, as well as parkinson's patients. and PS.. many people can walk into a Psych class and memorize Kohlberg's theory, or Garderner's theory.. it's what you take out and how you apply it that means something.. my original life goal was to be a Psychologist, mind you... PS#2.. Sephiroth is the boss-man. And for Blazarwolf, you're right.. the DO thing was uncalled for.. many people look down on DO versus MD.. but i actually prefer the philosophy that DO schools claim.. (interpersonal therapy style.. working with the patient, etc...kinda like psychotherapy)... and yes.. I am the hardest worker I know.. I get yelled at by my Girl friend to stop working on Hw and studying.. I get told to "chill out" with my study habits by people all the time.. i have a keen ability to sit their and read and soak up info for hours at a time. My weekends consist of out of 48 hours, 30 are working on school.. usually bio and chem.. I want to learn them for their implications in medicine.. but if i was taking A&P right now, forget it.. i love it.. i'd sit their on my free time and read that stuff . This is what I want, and I will do my all for it. Future patients deserve someone who worked that hard to be there.. and I intend on giving it to them.

jdurg, awesome point, you're right.. S2O2 would be a peroxide right? And yes, it's covalent, that much i know! 2 Non-Metals!

shweeet.. im getting the hang of it.. thanks for the help.

waitttt.. SO2 is a peroxide... so it is 2-... but only 1- when paired with H (H2O2 >>hydrogen peroxide).. is that right? ..so if it is 2-.. than the S will be 2+ to balance?

I sit here, trying to do a dry lab, never took chem before, and now I'm premed in College... awesome.. so as the other students seem to have a nice grasp b/c this took this course in HS already (or failed once before), I'm stuck with the assumption that I should "know" this already, and I'm far from understanding it.. My lab has questions such as this: "indicate the oxidation number of carbon and sulfur following the compounds" a) Na2C2O4 b) SO2 ...etc.. is this right?.. Na has +1 oxid#, and there's 2, so it's 2+; O4 is 2-, there's 4 of them so.. 8-.. 8- + 2+ = 6-... there's 2 Carbon.. so each carbon must = 3+ to balance this...i have no idea what I'm doing.. i'm just trying to figure it out.... and for SO2.. oxygen is a peroxide.. so it's 1-...but S never has a charge of 1+ according to the PToElements... WTF.. if you can help.. thanks a mil.

2 days... 47 views.. not one response?... PS. im also a subscriber to the New England Journal of Medicine, and a Journal of Neurology Called "Brain", published by Oxford U. Press.

that makes so much sense. That will be my answer. Thank you very much!