Homework Help

If 75 mL of 0.01 M HCl is added to 100 mL of 0.15 M acetate buffer (pKa = 4.7) at pH = 5.7, what is the resultant pH?

an enzyme catalyzes the phosphorylation of creatine from ATP, yielding creatine phosphate and ADP. Using the values on Table 3.3, first calculate the standard state free energy change for this reaction. Then, calculate the equilibrium constant. PLEASE HELP IM SO LOST!

Sorry for the hibernation recently I have assignments in and this question has had me stuck for 2 days straight. What I get for the first 2 parts of the question is to apply poisson's equation with cylindrical coordinates. Only the radius will change so del squared will only consist of the radius. For the general solution I get the following: V( r )=(p/6EE_0)(r^2)-(A/r)+B I am completely stuck on part C. I think that the boundary conditions are: V(a)=V(2a)=0. I use simultaneous equations to solve for A and B but my result is completely different to the solution given in C. Where do the logs come from? Where have I gone wrong? I would be very grateful if someone co…

Hello science forum and thanks in advance for the help I want to design in principle and test if a space elevator design could be possible already today I was thinking about the space elevator design and saw that its shortcomings was that the cables used to connect earth with the satelite in orbit were not strong enough today. Then i came to the conclusion that to solve this with today technologies one would ve to make breaks for the cable so it doesnt break under its own weight. This i thought about doing with helium filled balloon or stations that would carry the weight of the previous branch of cable and relieve the weight of the above section. What…

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Could you help me with them, please. The bedrock plateau at a depth of about two meters and consists of almost unweathered quartz sandstone. Which of the following geophysical methods might be principally used to locate the ditch and why ? Gravimetry [density = density]. Magnetometry [magnetic susceptibility]. Geoelectric (resistance) methods [resistivity]. Radionuclide methods [of uranium, thorium and potassium]. Seismic (refraction) measurements [propagation velocity of longitudinal seismic waves]

My teacher gave us a few homework questions regarding on arranging oxidizing agents on their strengths. I can tell if it's strong or weak if it's on a table... However, there's a question where we have to arrange it based on the voltage it produced?? For example: Reduction reaction Oxidation reaction Resulting voltage Cu+2 + e- --> Cu+ Pb ---> Pb+2 + 2e- 0.11V Cu+2 + e- --> Cu+ Ni ---> Ni+2 + 2e- 0.05V Cu+2 + e- --> Cu+ Fe ---> Fe+2 + 2e- 0.09V Can someone explain to me how to do it?? Thank you!

I was looking at some of the Chapter questions in my Evolution textbook (Evolution: Making Sense of Life by Zimmer and Elmen), and I came across this question that is just stumping me in Chapter 4. The question states: 5) In the past, morphological evidence alone was used to examine the relationships of the cetaceans to other groups. According to this phylogency (which I had attached): a) The extinct genus Ambulocetus is more distantantly related to the genus Balaenoptera than to the extinct genus Protocetus. b) The genus Equus (horses) is more closely related to the genus Hippopotamus (hippos) than to the extinct genus Pakicetus. c) More changes have occured in the wh…

For my science fair project this year I'm measuring the effect of temperature of a wire on resistance. The circuit I made is working, but when I try to use the ohm meter it doesn't display the resistance. Does anyone know what I could do? Images: http://imgur.com/a/nV7hM

I got a work and some parts confused me. Here's the assignment: You have about 100,000 Chinese news, with their news date and news sources (three kinds: 0 1 2). Now, you got 20 query results (20 different key words). Each results shows about 100 articles without their news date and sources. (They were sorted by the relevance with keywords) Please use the 100,000 news to train a model, recognize these results' sources, and sort them by published date. -- My question is I know some training models could be used, but I don't know how to transfer those Chinese terms into a number, coordinate or matrix. I also want to know what kind of information is the …

As shown in the figure, a 2kg mass and a 3kg mass hanging from the massless pulley are released from rest. After the 3 kg mass has fallen 1.5 m, it is moving with a speed of 3.8 m/s. What is the rate at which the frictional force dissipates energy during this time interval? My solution: The 3 kg mass has Fg down and a Tension force up and the 2kg mass has a tension force to the right and a friction force to the left. With my coordinate system, the tension forces cancelled out, and I got Fnet = Fg - Ffr Ffr = Fg - Fnet Fg = 3 * 10 = 30 N Fnet = Mtotal * a To find the acceleration of the system, I knew Vi = 0m/s, Vf = 3.8 m/s, y = 1.5m Vf2 = Vi2+ 2ay The…

Hi, i i have a few questions on momentum and collisions. 1)in a inelastic collision are both objects moving or can 1 be stationary. 2) In a elastic collision why is kinecetic energy conserved? 3) if kinectic energy is conserved in a elastic collision does it mean that it travels with the same velocity it had prior to the collision? And lucky last, a collision invovling dogems or bumper cars whould be what type of collision. Thanks,

Hi! I'm in the 8th grade working on a science fair project. i was just wondering if it was possible for bacteria inside microwaves to go into the food that you put in it to cook/reheat? I's really appreciate some help. Thank you!

I have an exam tomorrow and I have spent 3 hours trying to figure this out. I have the answer but not the method. You throw a rock from an edge at the speed of 12 m/s at an angle of 25°. You are 1,5 m above the edge and it is 10 m above the ground. No air resistance. Have calculated max height and time 0,61 s and 3,3 m b) how long is the rock in the air? c) how far from the edge (horizontally) does the rock land? d) what speed does the rock have when it lands? Answers b) 2,3 s (2,262) c) 24 m (23,51) d) 19 m (19,22) Please help me, am a bit desperate, really want to pass this test! I have figured out b and c Still need help with d

What is the importance of Figure 1 in this article? What can we infer from it? http://gnowledge.org/~sanjay/Advanced_Co... Thanks

I'm writing a thesis about Munchkin cats and their healt problem which are connected to their genetic mutation. I found that the characteristic of the short legs is linked to a gene called COMP. On the internet I wasn't able to find the locus of the gene in cat's genome and I only found these statement on a web site : chromosome A2: 13581271-13588841. If it's possible I would like to now what's the accurate meaning of the statement (what's A2, what's 13581271-13588841..)

PLEASE HELP: I will ask my questions on this topic.

So i want to find the expectation of a geometric Brownian motion: [math]E[e^{K^TW_t}][/math] Where K is a constant vector and [math]W_t[/math] is a vector of normal Brownian motions, both of length n. I assume that as [math]K^TW_t[/math] is a scalar I can just proceed in a similar fashion as the univariate case to get: [math]e^{\frac{1}{2}K^TK}[/math] But is it that simple or am i missing something as i suspect? As always, help very much appreciated.

Hi, I'm new to this site and was wondering if anyone can help me on an assignment. My assignment is about food heating packs. What happens to the surroundings in an exothermic heat pack, its energy changes, the chemicals in the heat packs the bonding breaking and making, oh and the word equations. I can't seem to find any of these things to research on the internet. So I'm hoping there's someone on here that can help me, because I'm at desperate point now. Thanks for reading xx

A satellite moves in a low circular orbit about a spherical earth that has no atmosphere (it barely skims the surface of the earth). Approximately how many minutes will it take the satellite to make one revolution around the earth? I think you would use Kepler's third law here, but there are no numbers and the answer choices are 80,82,84, and 86 minutes. How do you do this?

B. One of the compounds of a tomato is likopen. 1. which solvents can be suitable for an extraction in aquatic solution 2. Is Acetone is suitable for the extraction? I know it's a lot of questions, but there're more... C. 1. Explain the 'salting out' effect' 2. Why an addition of Ethanol causing the Emulsion to break? 3. Why do we add Na2CO3 to the solution? 4. Why do we add Na2SO4 to the organic layer?

A car accelerates uniformly from rest, covering a distance of 125 m in 5 s. What is the car's acceleration in m/s^2? I thought the velocity would just be d/t = 125/5 = 25 m/s And then I thought the acceleration would be v/t = 25/5 = 5 m/s^2 But apparently the answer is 10 m/s^2 Why?

If the temperature of a star increases from 10,000K to 30,000K, by what factor will the rate of energy radiated per second increase? What formula am I supposed to use to determine this?

Two balls of the same mass are thrown towards a wall and collide with it moving with a speed of 5 m/s. Ball A hits the wall and rebounds with a speed of 4 m/s. Ball B hits the wall and stops. Assume that the collisions times are the same for each ball. Compared to ball B, ball A has ____ velocity change, ____ momentum change, and ____ impact force. So I figured out that A has a *greater* velocity change because it changes from +5 to -4 whereas B only changes from +5 to 0. And I figured out that the momentum change for A is also *greater* because of the same reason above because momentum = mass x change in velocity. And I kept getting the last blank wrong, but appare…

How show the map [latex]f:\mathbb R^2\rightarrow\mathbb R[/latex], defined as [latex]f(x,y)=x+y[/latex] is continuous for all [latex](x,y)\in\mathbb R^2[/latex]? Question: I want to show the map [latex]f:\mathbb R^2\rightarrow\mathbb R[/latex], defined as [latex]f(x,y)=x+y[/latex] is continuous for all [latex](x,y)\in\mathbb R^2[/latex]. Issue: I know how to prove this via the epsilon-delta way. I want to prove this using the projection functions [latex]p_1,p_2: \mathbb R^2\rightarrow\mathbb R[/latex] where [latex]p_1[/latex] maps [latex](x,y)\rightarrow x[/latex], similarly for [latex]p_2[/latex]. Now my books says via a result based on continuous functions fro…