Homework Help

I am currently in Ochem 2, and my professor gave this set of proton NMR problems. We were asked to draw structures for the following compounds based on their NMR spectra: 1) C9H10O2 PMR: 8.1 (2H, d); 7.5 (3H, m); 4.4 (2H, q); 1.4 (3H, t) 2) C9H10O2 PMR: 11.6 (1H, s); 7.0-7.4 (5H, m); 2.9 (2H, t); 2.7 (2H, t) 3) C9H10O2 PMR: 7.3 (5H, m); 5.1 (2H, s); 2.1 (3H, s) For the 1st one, I am confused about the (3H, m); based on its shift I assume that it is part of an aromatic ring since the compound has 5 degrees of unsaturation, but I don't understand how it is 3H. For the 2nd one I got that it was an aromatic ring with CH2CH2COOH attached. For the 3rd one I got stuck …

I am supposed to do an essay on the following prompt: Heisenberg claims that you cannot know both the position and momentum of an electron with total certainty. Choose two other concepts that cannot be known simultaneously and discuss the implications. (Do not consider yourself limited to the field of physics). Here's my response: Though quirky in its origin, Heisenberg's Uncertainty Principle is a reflection of the laws of physics, and like other reflections of the laws of physics, it can be best explained as a statement about symmetry. Formally, symmetry is defined as invariance under transformation; x is symmetric if it is impossible to tell whether or …

Hi all, I am having problems working out some basic maths questions and would like someone to help me please ! 17+47=7+ ? 33+18=29+ ? 56+81=44+ ? 54-32=25-? 140/35= ? 150/100=? 3/5 x ? = 2/5 1/4+?= 3/4 2 3/5 - 4/5 = ? 60% of 120? 75% of 400? 22% of 200? 45% of 500? 33.6+8.7 = ? Also, these questions: - q1) If John starts work at 8:45 am and finishes at 5:15pm. He has 90 mins of breaks. How many hours does he work in 5 days? q2) A restaurant bill is made up of 12.50, 28.55, and 8.95, plus 15% service charge how much is the bill? q3) A team of 8 lumberjacks cut an average of 15,000 cubic feet of timber in a we…

How many grams of sodium succinate (140 amu) and disodium succinate (162 amu) must be added to 1L of water to produce a solution with pH 6.0 and a total solute concentration of 50mM? I use pH = pKa + log ([A-]/[HA]) and since pKa of succinic acid averages to 4.8, I get 6 = 4.8 + log ([A-]/[HA]) but then I get totally stuck...thank you!

Calculate the amount of glycine and HCl required to prepare a 1L solution of 0.1M buffer at a pH of 2.0. The pKa of the glycine carboxyl group is 2.4 and the pKa of the amine group is 9.6. The amu of glycine is 75. Using pH = pKa + log ([A-]/[HA]), I get 2.0 = 6.0 + log ([A-]/[HA]). I get 6.0 because that is the average of the pKa values of glycine. But we can't have the log of a negative number, so I'm totally stuck here... Thanks...

The problem is ∫ x5/√ (1+x3). I took 1+x3 = t2. I am supposed to get 2/3∫t(t2-1)/√t but what I get is2/3 ∫t(t2-1)/ t.. How did that square root "t" pop out? If 1+x3 = t2 then, √(1+x3) would be √t2 after cancelling the root then we get t. How am I suppose to get that square root "t" as the denominator? I am terribly lost.

Which of the followingstatements about polypeptides is not correct? Answer their structure is influenced by hydrophobic effects they are synthesized inside the endoplasmic reticulum they can recognize specific DNA sequences their function can be modified by phosphorylation they can fold to form helices, sheets, coils Which of the followingis not true of ribosomes? Answer they have codons in ribosomal RNA ribosomes catalyze peptide bond formation ribosome structure re…

Hi.. I'm having troubles with answering 5 questions..these were my previous exam question but doesn't have answer.. Can anyone please help? Q1. Which of the following statements about glucose homeostasis is INCORRECT? a)An injection of insulin would be a very, very, very bad treatment choice for a hypoglycaemic puppy b)Adrenaline and glucagon work synergistically to help achieve stable blood glucose c)In situations of extreme fasting, skeletal muscle would be broken down and reformed as glucose under the influence of insulin d)Hormones such as insulin can only influence a tissue or cell that as available the appropriate receptor e)Negative fee…

Hello I am having troubles with the correct usage of the terms "oxdised", "reduced", "oxidising agent", and "reducing agent". I understand the redox concept thoroughly, I would just like clarification on the usage of the words. I think the problem will be best illustrated using an example. Say, the reaction between Fe2O3 and CO: Fe2O3(s) + 3CO(g) --> 2Fe(l) + 3CO2(g) Oxidation numbers are as follows: Reactants: Fe = +3 O = -2 C = +2 Products: Fe = 0 C = +4 O = -2 Now here is the dilemma: Do I say "the Fe2O3 has been reduced, and has acted as the oxidising agent" or "the Fe has been reduced, and the Fe2O3 has acted as the oxidising agent", or a …

Please, I am in need of help. I'm having difficulty in answering this question: "Two tugboats towing a barge exert a force of 5.0 N each. If the angle between two ropes is 30 degrees, what is the resultant force exerted on the barge?" Anyone willing to help me with this + showing it thru graphing?

Please help me answer these? Please, before you tell me to do my own homework, I've tried doing them. I just need a general idea what to do. No one has to feed me the answers. :'( My professor gave us this homework just today and I only have one day to answer these. I just want to know what to do because I have no idea what to do. I really need a tutor but I can't seem to find anyone who likes Physics. I don't like Physics a lot if it isn't obvious enough. I've tried revising but it's just not helping :'( -- I've already answered 1,2 and 4. They're all I can manage to answer. 1. Two small plastic spheres are given positive electrical charges. When they are 15.0 cm a…

Hi, i doing an assignment in an algebra and differential calculus unit and it asks the following: The brightness, I, of a light beam that illuminates some surface is expressed by: I = (k*sinx)/(r^2), where k is a constant for the given source, r is the distance between the source and the illuminated point and x is the angle between the light ray and surface. at what height should you suspend a lamp over a round table of radius, a, so that the edge of the table is maximally bright. ? and in the old soln, it has: h = a/(square root of 2), but i dont understand how they get there... If anyone could give me something to go with that would be great, because the way…

Hello! I don't know how to solve this problem: find eigenvalues and eigenfunctions of quadratic membrane which is fixed in three edges. Fourth edge is flexible bended in the middle (at this edge membrane is in the shape of triangular). So I have u(x,y,t). Boundary conditions are: u(x,0,t)=u(x,a,t)=u(0,y,t)=0 and u(a,y,t)=k(t)*y for y < a/2 and u(a,y,t) = k(t)(a-y) for a/2 < y < a, where k(t)<<1 (because of that I don't have to account change of length of edge). Surface tension of membrane is γ, mass of edge is m. If anybody can help me?

Well, it's that time of year again... Science fair time. I love science fair, don't get me wrong, but sometimes it is so frustrating, thinking of ideas. Could someone try to point me in the right direction? Don't be afraid to give me a more techy idea, I'm into that stuff, and intelligent enough to grasp it. Thanks in advance for any help, this really is a wonderful community. MODS, PLEASE DO NOT DELETE, THE PROJECT IS TO EXPLORE THE IDEA, NOT TO COME UP WITH THE BEST IDEA. THEY CARE ABOUT THE PROCESS. I COULD MAKE A BAKING SODA VOLCANO AND WIN, YOU JUST CAN'T DO THAT MUCH INVESTIGATION OF A BAKING SODA VOLCANO...Ps I'm into electrochemistry and all that stuff. Chemistry…

I was thinking the first one would produce a cyclic ring with the oxygen and two methyls on the carbons attached to the oxygen. It would give one degree of unsaturation and still be C7H14O. Not sure on the others any hints or pointers would be awesome.

Hello I am in eight grade Science and I really need help on a homework. The homework is the following: Material: (Density (g/cm3)) Aluminum soda cans: (2.7g/cm3) Steel cans: (5.7 g/cm3) Milk jugs: (0.95 g/cm3) Soda bottles: (1.4 g/cm3) You can use the following things to help: • A long conveyor belt • A large tank that can be filled with water • Another large tank labeled “Concentrated sugar water, density = 1.5 g/cm3” • Several powerful magnets hanging above the conveyor belt • Several nets for skimming the tanks and scooping material from the bottoms. Your job: Find a way to separate the four recycled materials. If anyone can h…

Lepton ...Consider a planet which moves from A to B in a small time dT...under polar co- ordinate system let the radius vector be r vector from the origin o. that is OA = Ob = rvector angle AOX = y angle BOX = y+dy therefore change in angle is dy now let the planet move from A to B in small time dT....let it cover a distance dSvector ...here dA ( the area covered by the planet in time dT) = 1/2 rvector x dSvector dividing by dT .... dA/dT = 1/2 rvector x dS/dT ..... dA/dT =1/2 rvector x vvector multiplying and dividing by 'm'.. the mass of the planet .... dA/dT = 1/2m (r x mv) .... dA/dT = 1/2m (r x p)............. 1 differentiating 1 aga…

hey guys , i have a really important assignment to do first of all , this is the table i need to solve with the solutions, ELEMENTS | SYMBOL |no. of electrons| " " protons |" " neutrons |atomic no. |atomic mass _______________________________________________________________________ Lithium Li | - | 3 | - | 3 | 7 Carbon - | - | 6 | - | 6 | 12 Chlorine - | - | 17 | - | 17 | …

Hi, Question: A radioactive substance has a half-life of 20 days. i) How much time is required so that only 1/32 of the initial amount remains? ii) Find the rate of decay at this time. My Answer: i) Let "A" represent the initial amount. Let "t" represent the time in days. (1/32)A = A(.5)^(t/20) (1/32) = (.5)^(t/20) log_.5(1/32) = t/20 5 = t/20 t = 100 days ii) Let "A" represent the initial amount. Let "t" represent the time in days. f(t) = A(.5)^(t/20) f ' (t) = A (ln(.5)) ((.5)^(t/20)) (1/20) f ' (100) = A (ln(.5)) ((.5)^(100/20)) (1/20) = A (ln(.5)) ((.5)^(5)) (1/20) = A (-0.001083042) The rate of decay at 100…

Could I please get help with the naming of these organic molecules? Cheers.

Hello. Can someone explain to me the 2nd law of thermaldynamics in details? Thanks!

The question: Boy saw a ball first moving up and then down past an open window. The top-to-bottom height of window is 2.00m. Ball in view for a total duration of 0.50s. Calculate how much further above the window top did the ball move before reaching its highest point. [acceleration due to gravity = 10ms^-2 and ignore air resistance]. Answer is given, but i am unable to solve it. Tried using 1/2mv^2 and mgh etc., but still unable to. Anyone out there who knows...?

∫(1+tanx)/(1-tanx) the answer is supposed to be -log| cosx - sinx | + C, but I just can't seem to get there. Can someone please tell me the steps to get there?

I am not getting what actually an order of reaction is. What does it mean and what it has to do with the the rates of reaction. I've tried to read from books and I'm not able to understand, its significance, properly and I am also not able to solve the numerical problems related to it (where it is further associated with integrated rate equation and half life ). Please help.

What's the difference between "delay" and "penalty?" For example: branch delay, branch penalty, load delay, load penalty. Never-mind about above. In the questions, "delay" was meant to pertain to a single instruction, and by "penalty" the question meant the total penalty, given various statistics about the program (percentage of branches, etc). Damn ambiguous questions In regards to the classic 5-stage pipeline (IF ID EX MEM WB): If there is no forwarding, the correct target address of a branch will not be "available" (to other instructions) until the after WB stage, right? So, whenever there is a branch, the instruction at the target can't be fetched until the c…