Homework Help

A sample of 2.00 g of SO2(g) originally in a 5.00-L vessel at 18°C is transferred to a 10.0-L vessel at 25°C. A sample of 3.50 g N2(g) originally in a 2.50-L vessel at 20°C is transferred to this same 10.0 L-vessel. What is the partial pressure of SO2(g) in the larger container? I have NO idea where to begin............please help me get started. I'm not sure how to combine the containers...or how the temperatures or the volumes change.. :-(

(a) Place the following gases in order of increasing average molecular speed at 300. K: CO, SF6, H2S, Cl2, HBr. (Use the appropriate <, =, or > symbol to separate substances in the list.) So, I know how to do (a): SF6 < HBr < Cl2 < H2S < CO SF6 being the slowest and CO being the fastest. (b) Calculate and compare the rms speeds of CO and Cl2 at 300. K. rms speed of CO in m/s rms speed of Cl2 in m/s I have no idea how to do (b). Someone give me a start please? Thanks!

I have to identify the structure of an unknown compound given a nmr, IR, and mass spectrum. I'm not sure how to analyze the mass spectrum and not completely sure about the nmr. http://img.photobucket.com/albums/v31/PaperTigers/problem3pg1.jpg http://img.photobucket.com/albums/v31/PaperTigers/problem3pg2.jpg

First post here, mainly because I've never had this much trouble figuring out an answer. Here's what I'm stuck on: What is a taxa that is either a taxonomic or biogeographic relict but not both? I'm pretty sure this is going to be part of an essay question on my final later this week, and I've been stumped for a few days now. I know examples that are considered both, and there are some that would technically work, but we cannot use (ginkgo, humans). Any tips on where to look, or certain things to look for would be appreciated. Thanks in advance.

Hey guys, Here is the question: A mixture of gases contains 4.14 g of N2, 5.56 g of H2, and 7.06 g of NH3. If the total pressure of the mixture is 5.06 atm, what is the partial pressure of each component? Find the partial pressures of N2, H2, and NH3. Here is my attempt: I took the grams of each one, and converted them into their moles via their grams divided by their molar masses. I added up their mole weights to get one large mole weight. I think took each individual mole weight and divided by the total mole weight. With this percentage, I multipled it by the total pressure, 5.06, to get their partial pressures. What did I do wrong? - Because th…

So i have a very big delema. What i'm basically doing is taking an unknown culture (says theres only just 2 types of bacteria) and growing it on specific and differencial mediums to conclude which two types i have. So i may have one gram-postive and one gram-negative bacteria in the culture tube. First, i inculate PEA (phenylethanol agar) which is particularly for isolation of gram-postive bacteria. Then i inoculate EMB (Eosin Methylene Blue agar) is a selective medium for gram-negative bacteria. So after incubation i have postive growth on both mediums. Now i take both plates and inoculate MSA (Mannitol salt agar) from the PEA (if the MSA is fermented the pH of the med…

So I am doing lots of studying for my GenChem I final next Wednesday. Surprisingly, stuff I didn't get before is now coming rather easily . One thing that I am confused about, though, is the following question: What is the energy in joules of a mole of photons associated with visible light of wavelength 486 nm? I know how to work it out and everything. When worked out, I get the answer 2.46 × 10-4 J. However, the answer marked correctly (I looked it up on the net, too) is 246kJ. Why is the answer in kJ even though it is asking for joules. This isn't so baffling as the fact that another question almost exactly like it has the correct answer in J. Can anyone sh…

Hi! I'm new to this forum and would greatly appreciate any help or advice on this topic!!! I'm currently in a microbiology lab course in college and we have to identify an unknown bacteria. I have performed a series of tests on my unknown and I really believe it is Salmonella. However, there is still some doubt because some of my results don't match typical Salmonella reactions. So I was wondering if someone could confirm my theory or if they could lead me to a helpful website because I have searched for hours trying to find everything! I just want to be 100% sure that I'm correctly identifying this bacteria. Here are my test results: Unknown Bacteria: bacillus w…

I really need help with this question; my teacher told us that he is not going to be collecting these questions but that they might show up on the final exam next week; and I was not in class when we took it up due to my previous class (which was an Immunology lab where we were doing an ELISA assay, so it wasn't my fault) running late. The question is this; What is the purpose of the following transformation controls in the construction of Recombinant plasmids? a) Uncut plasmid b) Ligation of cut vector that hasn’t been phosphatased. c) Ligation of cut, phosphatased vector. I'm pretty sure that the uncut plasmid is used so that we can calculate the eff…

For my chemistry class, I have to make a fictional news report in regards to At first I had a brilliant idea of me doing a news report of beavers or some other aquatic animal found dead because they drank the water that was containmented with fertilizer, now I'm starting to have my doubts, are fertilizers able to seriously harm or kill small animals? And if so, what is the most dangerous kind of fertilizer?

Hey guys, I'm using this answer key to an old Biochem test for studying, but I don't understand the answer to Question 4a. Shouldn't the answer be Proteins A, D, and E? (link to answer key). (If you don't want to click that link, I copied the problem below, along with my ideas). Thank you in advance!

How would studying the proteins used in the cell division of embryo connect to cancer research?

Due to complexity of this problem i need to post the link to the hw https://blackboard.xula.edu/courses/1/80196.CHEM.4130.01.FA09/content/_162718_1/case_studies_cases_case29.pdf?bsession=2630730&bsession_str=session_id=2630730,user_id_pk1=9018,user_id_sos_id_pk2=1,one_time_token For question # 2 I have a hard time figuring out what they mean by the amino acid change of the enzyme. Appreciate the help. (fyi I located all the base pair for the amino acid) There was a mistake in justin base pair it should be 320 not 319

a) Express the total energy of an electron in the Coulomb potential of proton through the electron's angular momentum L and the shortest distance a between the proton and the electron's orbit. Hint: The electron's velocity is perpendicular to it's position vector whenever it is distance a away from the proton. b) For a fixed L, minimize the expression found in (a) with respect to a. Show that the minimum corresponds to the case of a circular orbit. State the minimum value of the total energy for fixed L. My only attempt so far has been: E=U+KE => E= .5L*v/a - e^2/[4πε0a] I have little confidence in that as a solution. Either I've stopped short or I'm going in…

Hi all; I conducted an experiment in my analytical chemistry class to calculate the concentration of glucose in an energy drink, such as gatorade, from known concentration glucose standards. Basically the experiment was to measure the current of the standards and prepare a plot of current versus concentration. I wanted to double check on here that to find the concentration of the glucose in the gatorade I would take the measured current of the unknown "drinks" and plug that data into a trendline generated from the standards with y= the concentration and x= current. for example; concentration = m*(current)+c with m being slope and c being some consta…

Can't quite figure this out... Why does sqrt[x(x+1)] tend to x+1/2 and not just x as x becomes very large?

How do you calculate that? The following results were obtained when a sample of microbes was serially diluted and the diluted samples used for spread plate experiment (0.1 ml per plate). Determine the CFU/ml in the original sample (express your answer to 2 decimal places). Dilution | Plate 1 | plate 2| 10^-4 | 450 | 360 | 10^-5 | 159 | 220 | 10^-6 | 37 | 45 | 10^-7 | 7 | 10 | The steps my lecturer taught me is: -Count the number of CFU between 25 – 250 colonies -Multiply the number by the reciprocal of the dilution -Gives an estimate of the number of bacteria/ml What does it means?

I don't even know where to start, it's for calculus. If At one point a bullet is shot 1900ft straight into the air. Find the exit velocity (Vo). The height (H) after (T) seconds is H = VoT-16T^2. All I've done thus far is find the derivative. Am I on the right track? What should I do?

of y=cos^2[(1-sqrtx) / (1+sqrtx)]? I tried using the power rule, then trig derivative of cos and quotient rule for the argument but i got it wrong.

Hi all, I'm currently doing an essay on the theories of colour vision (using the trichromatic and opponent theory). However, I'm having so much trouble understanding the opponent theory and how it actually functions. I'm wondering if anyone could shed some light on this? How can the opposing theory be explained and how could I propose a conclusion and evaluation of both theories? It's driving me crazy trying to get my head around it. Some ideas would be much appreciated. Many thanks, Evnissyen

What enzymes are involved in the following reactions A) lipid hydrolysis B) gelatin hydrolysis C) cellulose hydrolysis D) urea hydrolysis E) tryptophan hydrolysis JUST TO MAKE SURE IF IT'S CORRECT OR NOT: A) lipase C) cellulase D) urease

Hello. I am having trouble with a question in my textbook. If I have an 8.3 g sample of acetanilide (Solubility => 0.53g/100mL at 25oC and 5.0g/100 mL at 100oC) that needs to be purified by recrystallization, then what is the maximum % yield that can be recovered (10% excess of solvent was used)? I'm confused as to how I go about such a question, so if you could, please, hint at what path I am supposed to take, I'd greatly appreciate it.

I don't think I'm giving all the information in this homework problem, but I don't want to have the problem solved for me. I just need to know where to start. We were given the data for enzyme assays and all we have to do (in one to two sentences) is to explain the data. For example in problem (f), it seems like I have to go to a protein database and look up the structures based on the enzyme code, but i'm not entirely sure how to interpret the data once the structure is in front of me......

Righto, hi there! I'm conducting an experiment to identify microbes in water. So i've been give two agar plates--- the control's in the classroom. I've chosen water as my subject, and i have to grow microbes/bacteria on them. I was thinking about pond water (found in a disgusting hole (?) at school) and normal, bottled water, most likely Mount Franklin Bottled water. So i know what to do... just applying it onto the agar plates is the bit.. D: I've read numerous methods, and they all involve THE LOOP. D: I do not possess such an item at home, and i doubt the school will lend me one... >.< So i thought, after researching some more-- why not swabs? A…

Hi all, I've got an essay to write on the activation of cell surface receptors, specifically hormones and neurotransmitters. My local library hasn't been much help, so I was hoping someone here might be able to point me in the direction of useful literature on the subject. I have a couple of books, but not enough to write 1500 words. I'd prefer to steer clear of wikipedia if possible. Many thanks in advance!