Homework Help

Hey guys, i just need som help on changing the pH of certain solutions... I've been asked the question "if it takes 5500L of Caustic to change the pH from 11 to 10, how much caustic does it take to change the pH from 5 to 6?" will I need more or less? is there a formula you can use to find this out? i've researched and found that each individual pH unit is a factor of 10 different than the next higher or lower unit. is that right? Any help would be appreciated... thanks guys

Given: 1) 2K2Cr2O7 + 8H2SO4+3C2H5OH --->2Cr2(SO4)3+2K2SO4+ 3 CH3COOH + 11 H2O 2) K2Cr2O7 + 6 KI + 7 H2SO4 ---> Cr2(SO4)3 + 4 K2SO4 + 3 I2 +7H2O 3) I2 + 2 Na2S2O3 ---> 2 NaI + Na2S4O6 10mL of 0.0025 M K2Cr2O7 Initial Volume of Na2S203 25mL of .0010M Na2S203 final volume of Na2S203 12.39mL of .0010M Na2S203 How many moles of Na2S2O3 reacted in reaction 3. How many moles of K2Cr2O7 that reacted with the ethanol in reaction 1.

Okay, so heres the deal. I have a paper due tomorrow about how i plan on making an ecosystem in a bottle, and what im going to test. But i have NO idea where to start. Mostly i need an idea for an experiment. It has to test how ecosystems work etc..not just the plants in it. What should i test? i was thinking maybe seeing if plants grow better on their own or with other types of plants inside of the bottle, is this a good idea? any ideas?

i have this major project for Energy Conversion...Module or research peper bput Le chatelier's principle..i fhave founded some but still, can not be consider as a research for it just contain 5 pages. please someone help me to find some more articles and it is much much great if it is a simulation or applet something like that.. tnakz alot!!!

I have this midterm project due next week. It requires me to interview someone in my field of interest, chemical engineering, with questions revolving their experience in this field. This would give me some insight as to how my future career would be like. If any of you readers just happen to be a chemical engineer and have a few minutes to answer these questions and do not mind any follow up questions I may have in response, please leave a reply or if you prefer you can email garrett186@gmail.com or PM. Thank you. The questions are as follows: Why did you choose to work in this industry? How many years have you been working in this field? Did yo…

What is the longest cell in the human body?

1. the base of a solid is the region in the xy plane bounded by the parabolas y=x^2 ans x=^y2. find the volume of the solid if every cross section perpendicular to the x-axis is a square with its base in the xy plane. 2. given y=x^5 - 4x^3 + 5x a. locate the exact or approximate intercepts b. identify any axis of symmetry c. determine the curves behavior at positive and negative infinity d. use the first and second derivative to locate turning points 3. find the area common to r=1+cos@ and r=3^(1/2) sin@ 4. specify the points of intersection of rcos@=1 and r=4cos@ 5. tnagents are drawn to the ellipse x^2/a^2 + y^2/b^2 =1 and the circle x^2 + y^…

Can someone please help me... I have been asked this question, "If it took 5500L of caustic to go from pH 10 to 11 how much is needed to go from 5 to 6?" and I answered 0.055L but i have been told that is wrong. Can someone please explain what the answer is. Thanks guys:D

Hello everybody! I have to answer a really easy question, but I just cannot find the information anywhere! What does the "H" in buffer H (a buffer for restriction enzymes) stands for? Could you please help me out? or tell me where I could find the information?

Hi guys Haven't posted in this forum for a long long time.. good to read over some more interesting stuff on here i havent had the time to for a long long time.. anyway here goes Dynamics (mechanical engineering) gave me this assignment question which is more of a study question for our final exam (because it doesn't count towards our marks) Here is the question: A thin ring and a circular disc, each of mass 'm' and radius 'R', are released from rest on an inclined surface and allowed to roll a distance 'D'. Determine the ratio of the times required. I firstly drew my FBD (free body diagram) and this is it: (take a close look at the direction of my fric…

Hi, I have a homework about productivity.. I have to find how productivity is auction in a factory or in a company. I found something about it. But they are not enough. If you help me I'll be pleased.. Thanks a lot. I can not speak English very well. So if I have a mistake I'm sorry..

What are Amino Acids?

Okay, I am completely stuck. I have a homework question that I just can't manage to find the right approach for. I know what I should do if I solve it manually, though it's a long process, but I can't manage to build the function, and I really -- really really -- need help. Quite urgently, actually. It's due tomorrow. I've been trying this for the entire day already. The sad thing is that the solution is probably quite easy, and I am going to feel really stupid but I'm going to risk it. The problem is this: Now. I am thinking that I need to do this in stages, so I have my representations of a, b, c and d:[math]a=(bx^2+cx+d-y)/x^3[/math] [math] b=(ax^3+…

hey guys, im doing my senior chemistry research project on the "chemistry of carcinogens in diesel exhaust". i've found lots of reports on this subject, but was wondering if anyone had any websites which i could find chemical equations and reactions in (as this is the point point of the project - the chemistry of...)??? Or any useful information would be greatly appreciated!! thankyou

Hi everyone, Just started my A-level in biology and am confused about how DNA replicates Unfortunately what I have been taught seems to go against the biology I previously learnt from GCSE- e.g. is DNA not found in the nucleus after all? Any help would be appreciated Cheers

What Evidence Suggests That Earth Was Once Molten? Thanks in Advance!

A bug lands on the top of a bald man's head (sphere shaped). It begins to slide off. (no friction). Prove that the bug falls off the man's head at a height that is 1/3 the radius. MY attempt at the solution Fnet = N - mg, N = (mV^2)/R - mg (because acceleration is centripeital) When the bug falls, the normal force equals zero, so (mV^2)/R = mg V^2 = gR V^2 = Vi^2 + 2gh V^2 = 0 + 2gh KE = 1/2 mV^2 so, KE = 1/2m(2gh) KE = 1/2 mV^2 = 1/2m(2gh) V^2 = gR so 1/2 m*gR = 1/2m(2gh) R = 2h or h = 1/2*R THe answer should be h = 1/3 * R What about my approach is incorrect? i'm essentially finding two different ways…

i need to make up a real ecosystem for my environmental science assignment. I have no idea on where to begin from.. can anyone smart overhere help me out ? btw if u dont know what an ecosystem is, then here is the definition: An ecosystem is a natural unit consisting of all plants, animals and micro-organisms in an area functioning together with all the non-living physical factors of the environment.

Hello All: I have a major homework issue and your help would be greatly appreciated. Here's the question: In what ways does volcanic eruptions and earthquakes affect global climate? Thanks.

Well, I have all summer to prepare for calculus based physics in the fall. I started last night and I've already come upon a problem. I'll just use this thread to ask questions instead of making 100 of them throughout the summer. Any help is appreciated. The problem is: A man throws a ball horizontally such that the ball leaves 1.5m above the ground. At what velocity must the ball leave his hand so that it reaches a point 20m away without touching the ground before it gets to that point? I got that the initial velocity in the y-direction is 0, which allowed me to find t. But that still leaves acceleration in the x direction and initial velocity in the x direction …

Why should we take notes during lecture in class?

Hello there. Im writing a paper for my Psychology of Sexuality class, about Extradyadic sex. Ive found 2 sources, but I need at least 2 more. Im looking for psychology journals. I have the ability to search through a database of journals, but I cant seem to find articles Im looking for. and when I do type in "Extradyadic" or "Extramarital" I'll get a few things that arent related to what Im going to write about. Im writing about why women and men may become involved in extramarital affairs. I need some search ideas. Also, if I could find some information on "Key Parties" or a "Key Party" that would be good too - because Im going to mention that as wel…

I have these two questions left to answer in an online TIMED quiz right now, and have no idea how to solve them. I've searched all through my text and notes and can't find anything. ANy help would be really appreciated! In a calibration experiment, a 1.04 millimole sample of Na2CO3 gave 0.82 millimoles of CO2 gas. If a 0.346 g of pure Na2CO3 was reacted with excess acid, what volume of gas will be measured on this apparatus (in Litres at STP)? (Hint: Start by calculating the percent yield) The antacid in question (with an active ingredient of Ca(HCO3)2), upon treatment with excess hydrochloric acid, a 0.433 g sample gives 88.15 mL of CO2 at 25.00oC and 1.000 atm. …

Theres a straight line (l) and a polar co-ord of a point A (p, alpha). The straight line passes through A and is perpendicular to OA. Ive got to prove rcos(theta - alpha) = p Any ideas where to start with this. I've got y = tan(alpha)x for OA.

What are RFLP,and what are their importance in genome analysis?