Number of results: 54,186
Chemistry -repost thank you in advance
I have a bottle of 95% ethanol purchased from the manufacturer. Normally, when it is not stated, does it mean 95% w/w ethanol? I need to prepare 100ml of 40% v/v ethanol solution from 95% ethanol. Please show me the calculation steps. Thanks.
September 20, 2010 by annie
Known: Cyanaocetic acid Ka=3.55*10^-3 ionization equation: HC3H2NO2<==> H^+ + C3H2NO2^- Unknown: pH of 0.4M of Cyanaocetic acid How can I find out the pH of 0.4M of Cyanaocetic acid ? Is there another way solving for it other than using ICE chart? Please help me out.I ...
April 21, 2009 by anonymous
physics EM repost
Magnetic resonance imaging needs a magnetic field strength of 1.5 T. The solenoid is 1.8 m long and 75 cm in diameter. It is tightly wound with a single layer of 2.50-mm-diameter superconducting wire. What size current is needed? Thanks in advance
March 31, 2008 by Spencer
question repost damon
Since some tutors dont check back, i want to repost this to damon: what percent more than 1/3 is 3/5? It said 3/5 was wrong, and I tried but i don't know what happend
September 12, 2014 by Bobby
Bobpursley can you help me with my problems below?
I had problems from yesterday but I still don't get them can you help?do you want me to repost? repost: I cant find them.
March 4, 2007 by Margie
What is the difference between an ionic bond and a covalent bond? I just keep forgetting which one is which...any easy way to remember these? PS> I know that you're not supposed to repost until 24 hours but I really need this answer! Thanks -MC
February 5, 2009 by mysterychicken
Homework Help Forum: brain teaser help Current Questions | Post a New Question Answer this Question | Further Reading Posted by sam on Sunday, April 2, 2006 at 3:34pm. try to find the error. I couldn't; it's very hard. A B C D E F G H I J K L M N O P Q R S T U V W X Y Z did ...
September 10, 2006 by chris
Write formula equations and net ionic equations for the hydrolysis of sodium carbonate in water. Responses Chemistry - DrBob222, Friday, April 24, 2009 at 10:50pm The hydrolysis of Na2CO3 ends us as the hydrolysis of the carbonate ion. The molecular formula is Na2CO3 + HOH==...
April 25, 2009 by anonymous
need to apply the moral theory of rule utilitarianism in my essay but i dont really understand what it is. i tried google and wiki but it doesnt really provide me with clear meaning, or examples. could someone please explain to be as simple as possible what RULE utiliarianism...
October 12, 2007 by melinda
Math - repost for Anonymous
Can someone show me the steps to these questions (I will provide the correct answers)? Thanks in advance. 1. When the polynomials 4x^3 + mx^2 + nx + 11 is divided by x + 2, the remainder is -7. When the polynomial is divided by x - 1, the remainder is 14. What are the values ...
September 28, 2007 by Writeacher
ACCOUNTING (Advance Sales)
Hi: I am unsure of how to adjust Advance Sales. For Year End, DEC 31, 2011. If my Unadjusted Balance for advance sales is $324,000 and I am told the following: 75% of the balance in Advance Sales is for garments to be made and delivered in 2012; the remaining 25% is from sales...
January 27, 2013 by Anon
on the 1st page can someone please help me??????? Its the 2nd and 3rd black dot next to my nasme. Even if this is a repost, more information needs to be given before we can adequately respond. Please repost with more information. Thanks for asking.
April 29, 2007 by Mack
The case In Re: Guardianship of Schiavo is an example of: A. why only the elderly need advance directives. B. the importance of advance directives, even if someone is relatively young. C. a case involving anatomical gifts. D. what happens when a person leaves conflicting forms...
February 3, 2012 by Andy
Chemistry - v/v versus w/w
Thanks a lot:) So just to confirm: normally for any chemical bought from manufacturer, if it is not stated, the % usually means v/v? Seems like for conc sulphuric acid, when it is stated 97% sulphuric acid, it means 97% w/w sulphuric acid? Thank you very much. Posted by annie ...
September 20, 2010 by annie
To Ron: Chemistry 12
I've deleted your 14 chemistry questions because you've made no attempt at answering them. This is not a site to dump homework questions like so much garbage to be disposed of. If you'd like to repost any of them with your answers, someone may be able to check them.
November 24, 2009 by Ms. Sue
"It is the case that good communicators advance more quickly in the company." Which of the following statements would be the best revision of this sentence? A. "It is the case that good communicators advance faster in the company. " B. "it is true that good communicators ...
January 10, 2014 by Minnie
"It is the case that good communicators advance more quickly in the company." Which of the following would be the best revision of this sentence? "It is the case that good communicators advance faster in the company." "It is true that good communicators advance more rapidly in...
December 1, 2011 by pam
It is the case that good communicators advance more quickly in the company.Which of the following would be the best revision of this sentence? a) "Good communicators advance more quickly in the company." b) "It is true that good communicators advance more rapidly in the ...
March 8, 2010 by vedrana
1.)The making of the nuclear reactor was an advance in a)Science *b)Technology c)none of the above 2.)The development of the airplane was an advance in a)Science b)Technology *c)none of the above 3.)The discovery of gravity was an advance in *a)Science b)Technology c)none of ...
July 2, 2010 by Ariel
History *repost* (sorry!)
After the Gupta Empire collapsed, what group gained control of much of India? Muslims from Afghanistan Buddhists from China*** Christians from Ethiopia local Hindu princes Which of the following was NOT a part of the organization of the early Christian church? the pope the ...
October 6, 2014 by SkatingDJ
Which of the following is NOT truly an advance directive? A. Living will B. Do not resuscitate order C. Advance funeral arrangements D. Designation of a health care surrogate is it B im confused
February 3, 2012 by Andy
Calculate the concentration, in percent by mass, of a refrigerant brine solution which is 4.03 M in NaCl with a density of 1.116 g mL-1. detailed answer, please, i dont understand how to do this at all!!!
November 10, 2007 by keely
(-2x2y)3 * (5xy3)2 *I don't get this on at all!!! Are there any exponents in this one? If so, repost showing the caret to indicate the exponent. oh sorry I forget to do that.LOL!Here it is now: (-2x^2y)^3 * (5xy^3)^2 Are there any exponents in this one? If so, repost showing ...
November 8, 2006 by Sandro!
Please refrain from reposting the same question within a short time (less than a day). If you do repost, add "repost" at the end of the subject. Quadruple posting within an hour and a half means that teachers have to spend time reading the extra posts, which actually slows ...
October 6, 2009 by MathMate
What is the hydrogen ion concentration, in mol dm−3, when 2.00 g of sulfuric acid is dissolved in water to give 0.400 dm3 of solution? could you explain in a simple and clear way please because im not very good at chemistry. thanks in advance
May 19, 2013 by becky
How do you factor 3x^2-x-4? thanks in advance How do you factor 3x^2-x-4? thanks in advance 3 times what = 3? 3 of course. giving you (3x+/-a)(1x+/-b). a and b can only be 1 and 4 or 2 and 2. Can you take it from here? (3x-4)(x+1)?
May 10, 2007 by Diana
Repost .. Saccharin is a weak organic base with a Kb of 4.8X10^-3. A 0.672-g sample of saccharin dissolved in 30.0mL of water had a pH of 12.34. What is the molar mass of saccharin?
March 20, 2013 by V
chem -repost for bobpursley
i don't know how to solve this. looked through all my notes but i'm not sure what kind of formula i am to use or if i even need one! please help me to understand the theory behind this: "calculate the work need to make room for the products in the combustion of S8(s) to SO2(g...
April 17, 2011 by please, help me
What is the difference between an ionic bond and a covalent bond? I just keep forgetting which one is which...any easy way to remember these? PS> I know that you're not supposed to repost until 24 hours but I really need this answer! Would this answer work?: In an ionic ...
February 5, 2009 by mysterychicken
List the total number of each type of atoms in the following reactants. A) 2HCL + Ca(OH)2 = 6 hydrogen, 2 carbon, 2 lithium, 2 calsium, 4 oxygen B) 2Na3PO3 + 3Ca(NO3)2 This one is a bit more complicated. May any chemistry teacher show me how to do this. Thank you very much in ...
July 11, 2010 by Derrick
corrected repost chemistry
to what volume should you dilute 125mL of an 8.00M CuCl2 solution so that 50.0mL of the diluted solution contains 5.9g CuCl2 I have a hard time determing the M1V1=M2V2 is
November 6, 2011 by Monique
The program plans to acquire a total of 600 end items costing $570 million over a five-year period. The first production contract is to be awarded in FY04. The number of items to be procured (not delivered) each year and their estimated cost (in then-year dollars) is shown ...
March 20, 2013 by CHUCK
Chemistry-Repost for DrBob222
My question was: A saturated solution of MgF2 at 23 degrees C was prepared by dissolving solid MgF2 in 1 L water. The Ksp of MgF2 is 1.5e-5. a.)Calculate the mass of MgF2 dissolved. b.) When .1 mols of solid KF was dissolved in the MgF2 solution, precipitation was observed. ...
March 21, 2014 by Anonymous
I'm sorry I had to repost, but this is urgent and i need it done by today!! Can someone please show me how to do these problems? I've been trying but I'm having a hard time... 1.Simplify the expressions on each side of the equation to obtain an equivalent equation: 5x + 12 + ...
May 2, 2009 by mysterychicken
Fundamentals of Business Financial Management
Your program plans to acquire a total of 600 end items costing $570 million over a five-year period. The first production contract is to be awarded in FY04. The number of items to be procured (not delivered) each year and their estimated cost (in then-year dollars) is shown ...
August 19, 2014 by Pat
a $200 cash advance by using checks linked to to her credit card account.The bank charges a 2 % cash advance fee on the amount borrowed and offers no grace period on cah advances.Sidney paid the balance in full when the bill arrived.What was the cash advance fee? What was the ...
January 31, 2011 by tina
Repost Repost Bio
I asked this, and didn't get a very helpful response. Question: hi, i did this lab, from this website and I was wondering if anyone could come up with 3 sources of error, and they can't be human error. Thanks! You are saving me! Seeing as I am not allowed to post to the ...
February 26, 2008 by InSANELY URGENT(Science teacher help)
The mole fraction of acetic acid (CH3COOH) in an aqueous solution is 0.675. Calculate the molarity of the acetic acid, if the density of the solution is 1.0266 g mL-1.
November 10, 2007 by keely
Estimate the value of the equilibrium constant at 550 K for each of the following reactions. 1) 2CO(g) + O2(g) <==> 2CO2(g) 2) 2H2S(g) <==> 2H2(g) + S2(g) Thanks in advance!
July 18, 2010 by Miguel
chemistry lab repost
i need help locating a lab for regents chemistry. i have the data sheet but misplaced the rest of the lab. i know it's online somewhere, but i'm not sure which lab it is.. (what it is called). The data sheet has 3 charts on it, 1 titled 'solubility'. it includes water, alcohol...
March 15, 2009 by please help!
A student determined that ethanol was the best solvent to use for a recrystallization based on small scale trials. When the recrystallization was carried out on a larger scale, no crystals were obtained on cooling the hot solution. Why? and how would you overcome this problem???
January 25, 2009 by Matt
What is the boiling point of an aqueous solution that freezes at -6.7 degress C. Please help. I feel retarded because it seems like its something real easy but Im still not getting it. I did 100 + 6.7 and got 100.67 and are you sayin to divide 1.86 by .52 which is 3.576. the ...
November 5, 2011 by swtnblk
Just a repost, in case the old isnt seen
sorry! I never noticed..the mass should be 52000kg sorry about that! For Further Reading physics repost - Alexis, Sunday, October 14, 2007 at 6:07pm so it should be a 52000kg train slows from 25 m/s to 14m/s in 5.0 s. Calculate the work done on the train. so I found the ...
October 14, 2007 by Alexis
help, i'd like to know how to do this titration question: for example: a 1g sample of naoh contaminated with na2co3 is titrated with 0.500MHCl, and it is found that 46.5mL of HCl are required for neutralization. Find the percentage by mass Na2Co3. ( i did not make up these ...
April 21, 2008 by alex
Hi i am having trouble with this question: Name five household products that are not reactive, and for each product, describe the properties that make it ueful. Thanks in advance.
March 16, 2008 by Brooke
Did Christensen use any counterarguments in his article in AIDS in Africa: Dying by the numbers. yes he did use counterarguments. Were they need to advance his thesis? yes it was needed to advance his thesis. What do you think of my answers. please do give feedback on them
October 26, 2008 by anonymoys
When 155 mL of water at 26 degrees Celsius is mixed with 75 mL of water at 95 degrees Celsius, what is the final temperature of the mixture? (d Water = 1.00 g/mL) Im really stuck on this problem and chemistry isnt exactly my strong point, thanks in advance!
May 19, 2014 by David
Ermms just cant get my head around this question kinda bugging me :( Solid Sodium Hydrogen Carbonate dissolving in water i know its a dissociation reaction but i dont really have an idea where to split the compound. sorry about the repost, im new to this site and i aint really...
August 25, 2008 by (:
Dimension Personal Education
Select the sentence that does not have a pronoun-antecedent error. 1. If anybody wants to go to that new restaurant, she or he has to make reservations a month in advance. 2. If anybody wants to go to that new restaurant, they have to make reservations a month in advance. My ...
November 10, 2012 by Jackie
Can Someone describe the structure of ionic compounds for me please.. Ionic compounds consist of a three dimensional array network of + and - ions. I expect you already know that. As to structure, here is a web site that may help. Repost if you have additional questions but ...
November 15, 2006 by bryan
How do the qualities of acids and bases shape the natural world we live in? I really apppreciate, in advance, any help you can give me-I'm homeschooled and just trying to understand this better. Thank you-
April 26, 2010 by Sara
What is the (simplified) meaning of Zn(s) + 2MnO2(s) ZnO(s) + Mn2O3(s) [e° = 1.43 V]? Please answer soon, because I will not be in class too much longer and I have no internet access at home. Thank you in advance!
February 11, 2015 by Ani
What is the acid dissociation constant for a 0.010 M solution of the unkown acid HX that has a pH of 2.70 at equilibrium? I know the answer but not how to get it, please help? Thanks in advance.
November 29, 2012 by ciaociao
Pb(s) + KNO3(aq) ----> No reaction HNO3(aq) + Sr(OH)2(aq) ----> H2O + Sr(NO3)2 NO3 being Nitrate, and (OH)2 meaning 2 Oxygen and 2 Hydrogen atoms in the second problem. The second two in the products of the second problem is a subscript for NO3. Are these correct? Thank ...
January 31, 2009 by Momo
What is the difference between Entropy, Enthalpy and Free Energy. I'm getting really confused and I just need someone to explain it in simple terms please. Thanks in advance.
June 8, 2010 by CHeem
Write a balanced chemical equation that represents the reaction between methane and hydrochloric acid. CH4+HCl-> I'm not quite sure what happens...help please? Thanks in advance!
June 6, 2012 by Cicilia
What is the pH of a 0.16M KHSO3 solution at 298 K? a. 4.41 b. 1.31 c. 7.00 d. 1.82 e. 3.89 I did the calculations and my answer came out to be 3.89 but apparently the answer is 4.41. Can anybody explain why ? Thnx in advance
October 3, 2015 by Owen