Calculate the end point pH, when 25 mL of 0.01 mol/L HCl solution reacts exactly with 25 mL of 0.1 mol/L NH4OH solution. NH3 Kb = 1.8 x 10^-5 This will be the pH of NH4Cl solution. NH4+ + HOH ==> NH3 + H3O^+ Ka = Kw/Kb = (NH3)(H3O^+)/(NH4^+). Solve for H3O^+, then pH = - ...
May 31, 2007
Calculate the pH of a solute where 24.5 mL of 0.1 mol/L HCl is added to 25.0 mL of 0.1 mol/L NaOH. How much excess OH is there? .5ml .1M or 5E-5 moles. That is in a volume of 49.5ml So if OH concentration is that moles/volume, what is the H+ concentration? Remember the product...
May 31, 2007
Classify the following as: Weak or strong acid, weak or strong base, salt (from weak/strong acid and base). If appropriate, split the formula into its component ions. HNO3 So far, all I have is: HNO3 + H2O -> NO3^- + H3O^+ And I know HNO3 is a strong acid. What would I do ...
May 26, 2007
Use the Bronsted-Lowry definitions to identify the two conjugate acid-base pairs in the following acid-base reaction: H20 + H20 <-> H30^+ + OH^- Let's see what you think on this after the previous post. Just remember, the acid is the one that HAS the H and the base ...
May 26, 2007
Use the Bronsted-Lowry definitions to identify the two conjugate acid-base pairs in the following acid-base reaction: HCO3^- + S^2- <-> HS^- + CO3^2- I got it. HCO3^- is the base in the pair with CO3^2-. S^2- is the acid in the pair with HS^-. Would you believe you have ...
May 26, 2007
Zn + PbCl2 --> ZnCl2 + Pb The initial mass of a zinc strip is 2.684. After being left overnight in a lead (II) chloride solution, the mass of zinc is 2.581g. Calculate the Ksp of lead (II) chloride. So far I have: PbCl2 --> Pb(aq)2+ + 2Cl(aq)- Ksp = [Pb(aq)2+] [Cl(aq)-]^...
May 23, 2007
How is Hamlet a hypocrite towards Ophelia? I have one example, which is that he says he loves her but is the cause of her death because he rejects her and kills her father, which causes her madness and subsequent death. I need one more example, but I can't think of him ...
May 16, 2007
I posted this yesterday, that I need to modernize an Ancient Greek myth. bobpursely replied with an idea that I could do the Siren sisters as cheerleaders, but I couldn't find a myth about them, they're in two different myths. Like I've been thinking of myths such ...
May 10, 2007
I have to modernize an Ancient Greek myth, does anyone have any ideas? Sure. Reset the place and time of the Siren sisters (cheerleader sisters?) occupying a booth at the local Ice Creame shop, tempting Jason (basketball dude hero), Argo (Computer Programmer dude), and ...
May 9, 2007
Why can't a equal 1 in y=log(base a) x. And why is x always positive in that? Hmmmm. a^y=x (from the problem statement). If a were to equal 1, then x would be 1 (1 to any power is 1). So if a is not one, but a positive number, then x has to be a positive number, if one is ...
May 8, 2007
Find the inverse of each relation: y = (0.5)^(x+2) and y = 3log base 2 (x-3) + 2 For the first one I got y=log base 0.5 (x+2)...but the answer in the back of the textbook says that it is not x+2, but x-2. Can someone tell me why it would end up being x-2 and help me with the ...
May 6, 2007
How is Hamlet hypocritical with Rosencrantz and Guildenstern? Provide 2 examples. Please note that we don't do students' homework for them. Our tutors try to give you the information to help you complete your assignment on your own. Be sure to go back into your ...
May 3, 2007
Create a function that has a graph with the following features: Two vertical asymptotes: x=1, x=3. One horizontal: y = -1. And x intercepts= -2, 4 how about f(x) = ((x+2)(x-4))/((3-x)(x-1)) ?
April 26, 2007
Hi, I'm writing an essay on "what makes a city world-class"...I have all of my points and everything set, I'm just stuck on how I should start my essay. I can't think of any good introductory sentence. Your introductory sentence should be something VERY ...
April 9, 2007
How is commercial root beer carbonated? Yeast-carbonated root beer contains a small amount of alcohol. ... which contain the same sort of artificial colors and flavors as commercial root beers. Since this is not my area of expertise, I searched Google under the key words "...
April 1, 2007
Can hypochlorite ions oxidize bromide to bromine? In acid solutions, yes. That's the old qual test for bromide. Shake a solution of the unknown with NaOCl, this oxidizes bromide to bromine, and the bromine colors the carbon tetrachloride layer (added previously) yellow. Of...
March 20, 2007
When hypochlorite ions act as an oxidizing agent, hydroxide ions are formed. What will this do to iron (II) or to iron (III) ions? Both Fe(OH)2 and Fe(OH)3 are insoluble in an aqueous solution.
March 20, 2007
Write an equation to summarize the photo reaction of photosynthesis. Since this is not my area of expertise, I searched Google under the key words "photosynthesis equation" to get these possible sources: (Broken Link Removed) http://en.wikipedia.org/wiki/...
March 15, 2007
I need to prove that Hamlet cares about/loves his mother or cared about her/loved her at one point. Since this is not my area of expertise, I searched Google under the key words "Hamlet mother love" to get these possible sources: http://220.127.116.11/search?q=cache:...
March 12, 2007
Does the conversion of hydrogen peroxide to oxygen involve oxidation or reduction? What substance is acting as the oxidizer or reducer? and Does the conversion of hydrogen peroxide to water involve oxidation or reduction? What substance is acting as the oxidizer or reducer? ...
March 10, 2007
I needed to write an essay on how Hamlet is a hypocrite and my three points were that he doesn't obey his father right away, he says he loves his mother but treats her badly, and he says he loves Ophelia but he is the cause of her madness. But now, my topic has been ...
March 6, 2007
Yesterday, I asked the question about my thesis statement for Hamlet. Heres what I wrote: Hi, I'm writing an essay on how Hamlet is a participant of hypocrisy. Can anyone help me write a thesis statement. My points are that his father tells him to avenge him, but Hamlet ...
March 5, 2007
Hi, I'm writing an essay on how Hamlet is a participant of hypocrisy. Can anyone help me write a thesis statement. My points are that his father tells him to avenge him, but Hamlet takes a long time to do it, how Hamlet says he loves Ophelia but is the cause of her death, ...
March 4, 2007
Hi, If anyone has read Hamlet...I have to write an essay showing how Hamlet is a hypocrite or similar. I need 3 main points of proof. I only have one, which is that Hamlet says he loves Ophelia but hes the cause of her death and he shunned her. I need two more points. His ...
March 3, 2007
How come two non-polar substances are able to easily mix? Like dissolves like. Yes, I know that, but is there any explaination to that relating to the bonds? http://www.newton.dep.anl.gov/askasci/chem03/chem03348.htm
March 1, 2007
Look up the boiling points and relative molecular masses of water, hexane, and ethanol. Try to explain the relative magnitudes of their boiling points in terms of polarity. I know that ethanol and water are polar and that hexane is non-polar. Also, 6)
February 27, 2007
How would you make a starch molecule? What is the name of the bond formed between glucose molecules? I think I got it. They are formed by long chains of glucose molecules joined together by a glycosidic link. Can anyone confirm if this is correct? I believe you are right. ...
February 25, 2007
Using molymods make 2 ring structures of glucose and join them through a condensation reaction between carbon 1 on one molecule and carbon 4 on the other. What molecule is formed through this procedure?
February 22, 2007
What kind of isomers can amino acids form? Which isomer is present in most living organisms? don't major compounds of living organisms consist of modifications of hydrocarbons Although D amino acids can be found in nature, only the L isomers are used to form proteins. The ...
February 21, 2007
What is the empirical distinction between emission and absorption spectra? In general terms, how did Niels Bohr explain each of these spectra? In general terms, emission spectra are obtained when the electron is at a high energy level and it falls to a lower energy level. In ...
February 7, 2007
A hockey puck travelling at 26 m/s [E 22* S] rebounds off the board at 21 m/s [E 22* N]. The puck is in contact with the board for 0.0025 seconds. Determine the average acceleration of the puck over the interval. average acceleration= change in velocity/time a= (Vf - Vi)/time ...
January 25, 2007
i am unable to this question complete the following by adding noun clause a)the fact is that__________________ b)this is a clear proof_______________ complete the following by adding noun clause a)Thefact is that______________________ b)This clearly proof__________________ The...
January 23, 2007
Calculate the period of the wave if it makes 10 vibrations in 2 seconds. Does anyone know the formula for this? frequency = (number of waves) divided by(observation time) = 10/2 = 5 Hertz period = 1/frequency = ?
January 21, 2007
When most people are asked what makes rockets lift off they say it's caused by the push of the exploding fuel against the ground. Explain why this is wrong. For every action, there is an equal and opposite reaction. That's from Newton, I think, but it may have been ...
January 18, 2007
What is the chemical equation for the combustion reaction between methanol and air? CH4 + O2 ==> CO2 + H2O. All hydrocarbons produce CO2 and H2O when they are combusted in air. The above equation isn't balanced. I assume you can do that? If not, ask OR take a shot at it...
January 18, 2007
Find the sum of two numbers whose sum is 70 and whose product is as large as possible. Ok i got that one equation is y = 70 - x...but how do I show an equation for a product which is as large as possible. The product is P = x (70 - x), where x is one of the two numbers. Set dP...
December 31, 2006
The Theorum of Apollonius states in triangle ABC, if M is the midpoint of BC, then AB^2 + AC^2 = 2AM^2 + 2MC^2. Prove this theorum using analytic methods. http://www.google.com/search?hl=en&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=Theorem+of+Apollonius+proof&spell=1
December 6, 2006
Geometry and Algebra
AB is a diameter of a circle with centre O. P is on BA extended, and PT is tangent to the circle. Use the corollary to the Intersecting Secants Property to prove that PT is perpendicular to OT. Here is the diagram (Without the dashes in the "com" and periods instead ...
December 5, 2006
A clerk pushes a filing cabinet of mass 22.0 kg accross the floor by exerting a horizontal force of magnitude 98 N. The magnitude of the force of kinetic friction acting on the cabinet is 87 N. The cabinet starts from rest. Use the law of conservation of energy to determine ...
November 30, 2006
Solving it would give u x = -4...but I am not sure how you would graph that. You see, a linear inequality is an inequality that has one of the following four forms: Ax + By < C Ax + By > C Ax + By < C Ax + By > C PLZ!Somebody tell me the answer! PLZZZ! umm,, It ...
November 28, 2006
Geometry and Discrete Mathematics (Proofs)
Observe that the last two digits of 7^2 are 49, the last two digits of 7^3 are 43, the last two digits of 7^4 are 01, and the last two digits of 7^5 are 07. Prove that the last two digits of 7^201 are 07. 7^2 = ...49 7^3 = ...43 7^4 = ...01 7^5 = ...07 7^201 = ...07 Break 201 ...
November 28, 2006
Algebra and Discrete Geometry
A large family wedding for the Smiths will require 113 trays of sandwiches, 116 trays of hors d' oeuvres, and 144 trays of sweets. Hands-Off caterers can make 15 trays of sandwiches, 10 trays of hors d'oeuvres, and 12 trays of sweets in one day. Hands-Free caterers can...
November 23, 2006