Number of results: 45,774
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
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
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
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
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
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
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
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
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
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)
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
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
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
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
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 (:
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
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
sorry i havent really used this site and im not sure how to repost my question instead of putting it as an answer to my question so heres the repost: I had to find embedded clauses I deplore the fact that bats have wings. --> bats have wings That Guinevere loves Lorian is ...
July 7, 2008 by Anonymous
Can you direct me to a site(s) which can help with college chemistry and statistics? Here are a couple of good chemistry sites that pretty well cover the waterfront. I don't know any stat sites but if you will repost with the subject line of "math" I'm sure someone will help ...
February 19, 2007 by jules
Determine the volume of 0.240 M KOH solution required to neutralize each of the following samples of sulfuric acid. The neutralization reaction is shown below. H2SO4(aq) + 2 KOH(aq)---> K2SO4(aq) + 2 H2O(l) a) 26 mL of 0.240 M H2SO4 b) 143 mL of 0.14 M H2SO4 for a I got ....
March 19, 2011 by Rebekah
Chemistry-Repost for DrBob222
The reaction OH- + NH4+ = H20 + NH3 is kinetically first order in both reactants' concentrations. The rate constant is 2e10 1/M s. If 50 ml of .01 M NaOH is mixed with 50 ml of .01 M NH4CL, find the time required for the OH- concentration to reach 1e-4 M. Your answer: It ...
March 21, 2014 by Anonymous
|a+2 3z+1 5m|+|3a 2z 5m|=|10 -14 80| |4k 0 3 | |2k 5 6| |10 5 9| I needed to repost this. This is a matrice and I am trying to find the values of the variables in each equation.
December 17, 2009 by mike
chemistry HMWK help....... REPOST
you decide to have a BBQ in your backyard. you have 1Kg of pentane (C5H12) in the tank. What is the amount of carbon dioxide (in mass and mols) you will be contributing to the greenhouse gas effect by using up that 1Kg of pentane? plz.... need the answer with steps...thank you...
November 11, 2010 by tarkan
chemistry(check my explanation)
sorry to repost this question but i'm confused on this part The solubility of borax is directly proportional to temperature. Therefore, the sign of H is A. negative B. positive C. unknown with the given information like you said earlier, borax dissolves when heat is added, ...
April 5, 2010 by eng
Calculate the force of gravatational attraction between two spheres of mass 10.1 kg and 45.4 kg that are 38.5 m apart. F = G(m1)(m2)/r^2 = 6.67 x 10^-11(10.1)(45.4)/38.5^2 = 2.06 x 10 ^-11 N
April 3, 2008 by Jon
AP Chemistry (repost)
some reactions that are considered to be spontaneous at low temperatures will not proceed at a measurable rate or form any measurable quantity of products for several hours, days, or years. a. explain why this is. b. will the addition of a catalyst alter the value of delta "G...
December 5, 2009 by anonymous
oxidation- reduction reactions What about them. Here is a site that may help you or repost with a more specific question. http://members.aol.com/profchm/redox.html
October 29, 2006 by Brianna
A 1.00-kg ball is attached to a string of 0.50 m and swung in a horizontal circle with a velocity of 2.00 m/s. Find the centripetal acceleration. ac=v^2/r = 2.00^2/.50 = 8.0 m/s^2
April 3, 2008 by Jon
What are charateristic of a ionic bond and a chemical bond? Answered below for characteristics of ionic bonds. I don't understand characteristics of chemical bond since an ionic bond is a chemical bond. Perhaps you can rephrase your question. For my partial answer look on this...
November 30, 2006 by Pretty in Pink
To Sha -- Child Development
I've removed your lengthy post asking you to comment on a complex scenario. Please repost with your analysis of this situation. We'll be glad to help you then.
February 27, 2009 by Ms. Sue
Math(repost of #2 of last ?)
Write XY(with line over it) as the sum of unit vectors for X(8,2,-9) and Y(-12,-1,10). There's an example just like this in my book but I really don't understand it.
April 25, 2009 by Jon
Does this equation need to be balanced? AlCO3 => AlO+CO2 Also, how would this equation be balanced? NiCl+O2 => Ni2O3+Cl2O5 Neither equation you have is an equation so they can't be balanced. Do you mean aluminum carbonate. That would have the formula Al2(CO3)2. Aluminum ...
December 14, 2006 by Carter
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
What would be the consequences of the following be on photosynthesis? These are the only ones I am stuck on! a.) Photosystem I is not functional b.) NADP+ is not present in the thylakoid space
March 23, 2008 by HELP! PLEASE SOMEONE ANSWER!
Pre-Algebra [repost for Reiny]
In my last post for #1, I asked my teacher and she said that it's actually k=30 . Could you have gone wrong somewhere? That's the only one. -MC
May 1, 2009 by mysterychicken
what does H2 + CH2 form? (what product?) What is CH2? There is a (CH)2 but I don't know of a CH2. Yes, I meant to ask: What product is formed by this reaction: H2 + (CH)2 My original answer is gone but I will repost. (CH)2 is HCtriplebondCH which is acetylene. H2 gas adds ...
October 29, 2006 by sara
describe a hypothetical situation in which collective naturalization might be applied? We do not do your homework for you. However, if you will repost your answer, we will be happy to proofread and give suggestions.
May 7, 2007 by angie
To: Troyer0269 - Sci245
I've removed both of your science posts. Please repost when you can tell us what you've done so far to fulfill these complex assignments and where you specifically need our help.
February 8, 2009 by Ms. Sue
To: Computer -- Cultural Diversity
I've removed your post with the complex assigment about subordinate groups. Please repost it and tell us what you've already done on this assignment and how we can help you complete it.
February 11, 2009 by Ms. Sue
I'm having difficulty on drawing lewis dot structures for certain compounds and figuring out the molecular shape. I can do the simple ones like IO4- which is tetrahedral...but i'm stumped on ICl4-. When i drew the structure I thought it was octahedral, but my textbook says it'...
October 7, 2006 by Melissa
Express the following in mol/kg [H+]in a water with a pH of 6.8? Ok, so the pH=-log10[H+]. Here we have a pH of 6.8 so we have... 6.8=-10log10[H+] solving we get... [H+]=10^-6.8 mol/L converting from Liters to m^3 and dividing by the density of water we get... (10^-6.8 mol/L...
January 20, 2007 by Jan
Repost repost physics
Posted by Meredith Mcneeds Help! on Monday, November 19, 2007 at 8:08pm. Hey, ok so I am supposed to be helping my cousin this with this physics problem, and this is the only one that has ever stumped me! Neutral metal spheres A and B each of mass 0.2 kg hang from insulating ...
November 19, 2007 by Meredith Mcneeds Help!