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April 19, 2014

Search: chemsitry

Number of results: 143

CHEMSITRY
Idk
Thursday, May 20, 2010 at 12:17pm by An

Chemsitry
i got it thanks
Monday, February 25, 2008 at 5:31pm by Anonymous

chemsitry
duplicate.
Sunday, January 31, 2010 at 11:58am by bobpursley

Chemsitry
Thanks a tonz !
Saturday, October 23, 2010 at 12:39pm by Anonymous

chemsitry
I did this for you earlier.
Saturday, October 23, 2010 at 2:35pm by DrBob222

Chemsitry
D. I just did it.
Monday, February 25, 2008 at 5:31pm by Anonymous

chemsitry
i need help for this quation
Tuesday, March 9, 2010 at 10:33pm by Asah

chemsitry
240 kj
Sunday, February 14, 2010 at 5:24pm by jimbo

Chemsitry II
.201
Thursday, May 10, 2007 at 7:13pm by Anonymous

Chemsitry
I answered this below.
Tuesday, November 13, 2012 at 6:12pm by DrBob222

chemsitry
1.04 kJ
Sunday, February 14, 2010 at 5:24pm by Anonymous

chemsitry
Duplicate post.
Tuesday, September 17, 2013 at 6:56am by DrBob222

chemsitry
I will be happy to critique your thinking.
Sunday, January 31, 2010 at 11:56am by bobpursley

chemsitry
DHrxn = (2*DH NH3)
Saturday, November 13, 2010 at 6:50pm by DrBob222

Science(Chemsitry)
I too wonder what it means
Thursday, June 16, 2011 at 2:43am by Atul

Chemsitry
See your other post.
Monday, April 1, 2013 at 8:40pm by DrBob222

Chemsitry
See your post below.
Wednesday, July 10, 2013 at 3:54pm by DrBob222

Chemsitry
-548 kJ/mol
Monday, February 25, 2008 at 5:31pm by many bunnies in UCI

Chemsitry
How do we improve the efficiency of Column Chromatography?
Thursday, August 19, 2010 at 1:35pm by Alan

chemsitry
what is the frequency of a wavelength of 764 nm?
Friday, December 17, 2010 at 1:06am by zahra

chemsitry
how do you find PH of {H+} = 1.0 * 10 to the -5 power M?
Sunday, May 13, 2012 at 12:39pm by ryan

chemsitry
How are we supposed to know what molecule you drew above?
Tuesday, September 17, 2013 at 6:57am by DrBob222

Chemsitry
ive looked in my book and cant seem to find it
Monday, February 25, 2008 at 5:31pm by Anonymous

Chemsitry
Strontium oxide; chronium(II)iodide
Saturday, October 23, 2010 at 12:39pm by bobpursley

chemsitry
Change nm to m and use c = frequency x wavelength
Friday, December 17, 2010 at 1:06am by DrBob222

Chemsitry
What is the name of the following ion compund. SrO Cr1I2
Saturday, October 23, 2010 at 12:39pm by Anonymous

chemsitry
hydrogen burns in oxygen to for water.caculate the volume?
Friday, August 3, 2012 at 7:58am by sam

Chemsitry
Did you retry the 548 kJ/mol again. I'd like to know if that was the trouble.
Monday, February 25, 2008 at 5:31pm by DrBob222

Chemsitry
Calculate the weight of KHP that will react with 25mL of .1M NaOH
Tuesday, October 19, 2010 at 4:07pm by Sierra

chemsitry
calculate Delta H of RXN 2 N2 (g) + 3 H2( g) ->2 NH3 (g)
Saturday, November 13, 2010 at 6:50pm by Sarah

chemsitry
How many moles of \rm CaC_2O_4 are present in this kidney stone?
Tuesday, March 12, 2013 at 12:16pm by indeus evans

organis chemsitry
what is the main structural feature of the azo dyes that causes them to be colored compounds.
Wednesday, December 29, 2010 at 10:47am by ME

chemsitry
buffer calculate the ph of the .1m propanoic acid Ka 1.35e-5
Sunday, April 10, 2011 at 9:09pm by neee

chemsitry
the ph of a .030M C2H5 COOH solution is 3.20. What is this acids Ka?
Saturday, May 12, 2012 at 8:20pm by ryan

chemsitry help again please
Write the formula of the conjugate base for acid HClO2 .
Tuesday, November 19, 2013 at 10:48pm by chelsea

chemsitry
calculate the work done when 50.0 g of tin dissolves in excess acid at 1.00 atm and 25c
Sunday, February 14, 2010 at 5:24pm by Anonymous

chemsitry
you start with 150.0g of pentane and 500.0L of O2. how many grams of H2O will you make?
Friday, March 29, 2013 at 1:09pm by sonya

chemsitry
The molecular geometry of POCl3 is tetrahedral. What hybridization does this indicate for the central P atom? Why is the answer spy?
Wednesday, December 11, 2013 at 3:36pm by Chelsea

Chemsitry
It just occurred to me that you may not be talking about carrier gas. Changing packing and eluent still apply.
Thursday, August 19, 2010 at 1:35pm by DrBob222

chemsitry
Calculate the work done when 50.0g of tin dissolves in excess acid at 1.00 atm and 25 C
Sunday, February 14, 2010 at 5:24pm by Anonymous

Chemsitry
i know i need to use the equations q=mcdeltaT and delta H= q/n but i keep getting the wrong answer. also which one is the limiting reactant...
Wednesday, June 26, 2013 at 12:33am by imstupid

Chemsitry
Outside of changing the packing and eluent you can change the flow rate of the carrier gas to allow more time withing the column.
Thursday, August 19, 2010 at 1:35pm by DrBob222

Chemistry
It doesnt let me link stuff :c But its the chemsitry toughhh q And i hope you are not typing the answer while i post this XD (sorry if thats the case) Thanks again
Sunday, November 20, 2011 at 12:43am by Matt

Chemsitry
q = mass H2O x specific heat H2O x delta T.
Wednesday, June 26, 2013 at 12:33am by DrBob222

Chemsitry
in the equation CaO(s) +2H+(aq)-->Ca^2+(aq)+H2(g)
Wednesday, June 26, 2013 at 12:33am by imstupid

Chemsitry
The Q1: what do you mean by find? Do you mean isolate, or where are Ions? The last three questions, check your text or the dictionary.
Friday, August 14, 2009 at 2:24am by bobpursley

11th grade chemsitry
If 150 g of water is heated from 3.0 celieus to 48.0 celieus how many joules of heat are needed
Monday, May 2, 2011 at 1:11pm by Trent

chemsitry
pH= -log{H+}=-log(1E-5)=5
Sunday, May 13, 2012 at 12:39pm by bobpursley

Chemsitry
I just took my Chemistry midterm, and would like to know how to calculate my grade on the midterm with the curve. MEAN = 8.9 STANDARD DEVIATION = 2.9 MY SCORE = 7 Thank You!
Tuesday, October 12, 2010 at 2:39pm by Anonymous

chemsitry
Pick a number and you will be right. The volume obtained obviously depends upon how much H2 you started with. Also you didn't specify the volume of what?
Friday, August 3, 2012 at 7:58am by DrBob222

Science(Chemsitry)
You have introduced a new term into Chemistry: percent by strength. What in the world is that? Normally, it would be w/w or w/v Without knowing what you mean, it is not possible to answer the questions.
Thursday, June 16, 2011 at 2:43am by bobpursley

chemistry
I am wondering the same thing myself!! Please someone! anyone! answer the question. In order to be more descriptive, is procion red dye a suitable substitue for PAHS for chemsitry lab?
Wednesday, December 2, 2009 at 7:51pm by Hannah

Chemsitry
Ksp = (Ca^+2)(SO4^-2) Solubility CaSO4 = S = 1.9g/136 = ??mole and that in 2L is ??/2 = (S) Then substitute the value for S into the Ka expression and solve for Ka.
Sunday, June 13, 2010 at 2:17pm by DrBob222

Chemsitry
For a particular redox reaction NO2 is oxidized to NO3 and Cu2 is reduced to Cu . Complete and balance the equation for this reaction in basic solution. Phases are optional.
Monday, April 1, 2013 at 8:40pm by Connor

Chemsitry
What is the phase of a compound at 600 mmHg and 32oC if it melts at 35oC when pressure is 760 mmHg? Its triple point occurs at 200 mmHg and 36oC.
Thursday, April 8, 2010 at 6:58pm by Dan

chemsitry
How would you figure-out which one is greater. You have 2.0 moles of H2O and 1.0 moles ofCO2 how would you get the answer.
Monday, December 6, 2010 at 11:26am by sherry

chemsitry
complete the following sentence. For an experimental measurement, the experimental value minus the accepted value is called the _______. absolute error
Friday, January 12, 2007 at 11:59am by Dennis

chemsitry
Calculate the mass in grams of sodium bromide, NaBr, are needed to prepare 250.0 mL of a solution of sodium bromide that is 3.50% (m/v).
Sunday, March 20, 2011 at 4:04pm by allen

chemsitry help again please
How does HClO2 dissociate? HClO2 ==> H^+ + ClO2^- The acid is the one with more H. The conjugate base is the one with fewer H.
Tuesday, November 19, 2013 at 10:48pm by DrBob222

Chemsitry
Use these data to estimate Avogadro's number. Palladium crystallizes with a face-centered cubic structure. It has a density of 12.0g/cm^3 , a radius of 138 pm , and a molar mass of 106.42 g/mol .
Sunday, June 17, 2012 at 1:02pm by Lauren

Chemsitry
Q1. How to find ions of a particular element.. Tell me the methods or procedure to do so? Q2. What are X-rays? Q3. What do u mean by "Irridated with X-rays? Q4. What do u mean by "radiation"?
Friday, August 14, 2009 at 2:24am by Akashdeep

chemsitry
rate constant= k[A]^m[B]^n is the general formula for mA+nB>C so here, that becomes r=k [N2O5]2 k= rate/(MolarityN2O5)^2 you need to know the concentration of the dinitrogen pentoxide.
Tuesday, December 8, 2009 at 6:45pm by bobpursley

Chemsitry 130
Can someone please help me with the=is problem... In each of the following, determine which reactant is being oxidized and which is being reduced: A. Al(s) + O2(g) -----> Al2O3(s) B. Ca(s) + F2(g) -----> CaF2(s) Thanks so much for the help ;-)
Thursday, October 8, 2009 at 2:12pm by Taylor

chemsitry
How will the osmotic pressure of an aqueous solution change as evaporation occurs? does it even change? or does it increase? evaporation will increase concentration, correct?
Tuesday, May 1, 2007 at 12:47am by sam

Chemsitry
Look up the standard state definition of a liquid (answer D) and see if the standard state of a liquid has a vapor pressure of 1.00 atm.
Monday, February 25, 2008 at 5:31pm by DrBob222

chemsitry
Why is the molecule you drew above more hydrophobic than dopamine? Describe the edit(s) that you made and how the change(s) make the new molecule more hydrophobic.
Tuesday, September 17, 2013 at 6:56am by sameua

chemsitry
Why is the molecule you drew above more hydrophobic than dopamine? Describe the edit(s) that you made and how the change(s) make the new molecule more hydrophobic.
Tuesday, September 17, 2013 at 6:57am by sameua

Chemsitry
M = mols/L or mols = M x L = 0.04826 x 0.405 = 0.019545 I think you just reported too few significant figures in the answer. You are allowed three and you reported only two. Of course my answer has too many.
Friday, March 1, 2013 at 11:08pm by DrBob222

Organic Chemsitry
Wouldn't that be 98.9 to 1.10? That is, on a scale of 100, C 12 will be 98.9 and C 13 will be 1.10. That is a ratio of 98.9/1.10 = 89.9:1
Friday, January 27, 2012 at 12:40pm by DrBob222

chemsitry
how do you find the bond order of OH- and OH+? I know bond order = #bonded e- - #antibonding electron/2 im not sure how to find Oh- and Oh+
Tuesday, May 20, 2008 at 9:26pm by Sarah

AP Chemsitry
When a weak acid is titrated half way to its equivalence point(18.74 is 1/2 of 37.48), the pH at that point = pKa. Solve for Ka from pKa = -log Ka
Sunday, April 1, 2012 at 5:15pm by DrBob222

Chemsitry
You have the answers mixed up with the number of the question to the point that the whole thing is confusing. The answer to the first question (H2SO4) is correct. The answer for what you have labeled 27A is blarney.
Monday, May 11, 2009 at 12:33pm by DrBob 222

chemsitry
What ions are very important for the proper fuctioning of biological systems such as nerves and cells? A)alkali earth metals B)hydrogen ions C)oxygen ions D)nitride ions E)alkali metal ions
Saturday, April 21, 2007 at 11:32pm by ninjaturtle

CHEMSITRY
I've not done this experiment but I assume if water enters the straw that the water level in the bottle will decrease, the volume of air above the water must increase, and the pressure must decrease.
Thursday, May 20, 2010 at 12:17pm by DrBob222

Chemsitry 2
a piece of nickel wire has a diameter of 0.568. if the nickel has a density of 8.90g/cc, how long( in meters) should you cut a piece of wire to obtain 0.0234 moles of nickel?
Monday, September 12, 2011 at 8:15pm by Smarth

Chemsitry
At 25 C, only 1.9 g CaSO4 (MM = 136 g/mol) will dissolve in 2.00 L of water. Write the equilibrium expression and calculate the equilibrium constant for the reaction below. CaSO4 (s) ⇋ Ca2+ (aq) + SO42- (aq)
Sunday, June 13, 2010 at 2:17pm by Michelle

Chemsitry
Yes, I think so. For first order, ln(Ao/A) = akt; therefore, for t = 0, we have ln(Ao/A) = 0 (Ao/A) = 1 and A = Ao = 1 Then I believe you are to use the original with t for t, and solve for (A). Same thing with second order but more challenging mathematically.
Saturday, July 17, 2010 at 3:33pm by DrBob222

Chemsitry
Consider the equilibrium A(g)=2B(g)+3C(g) at 25 degrees Celsius. When A is loaded into a cylinder at 10 atm and the system is allowed to come to equilibrium, the final pressure is found to be 12.13 atm. What is the standard gibbs free energy of reaction for this reaction.
Friday, January 31, 2014 at 2:56pm by Anonymous

chemsitry
What is the formal charge on each of the atoms in the Lewis structure of the PO4 (-3) charge? Draw another possible Lewis structure of the phosphate ion below. Formal charge on P is ? -how do I do this problem.
Saturday, November 13, 2010 at 6:48pm by Sarah

Chemsitry
I dont understand how to write this equation. Write an equation relating the concentration for a reactant A at t=0 to that at t=t for a first-order reaction. Define all the terms, and give their units. Do the same for a second- order reaction. -Would it be the rate law ...
Saturday, July 17, 2010 at 3:33pm by Jane

Chemsitry
Alpha, beta particles and gamma rays. How does the atomic number and atomic mass number change when a radioisotope decays to produce alpha beta or gamma radiation.
Monday, January 16, 2012 at 9:09am by Ryan

chemsitry
calculate the molarity of sodium in 12.4g of sodium acetate diluted in 100mL of ID water, and calculate concentration of both sodium and acetate ion in units of mg/mL,mg/L,and ug/mL?
Sunday, January 31, 2010 at 11:56am by Samah

chemsitry
3.50% m/v means 3.50 grams NaBr/100 mL soln. You can do this one of two ways (They really are the same but the look is different.) 3.50 x (250/100) = ?? or (Xg/250 mL)*100 = 3.50 and solve for X.
Sunday, March 20, 2011 at 4:04pm by DrBob222

Math
We have an important chemsitry test due and I want to make sure that I do not mess up on my algebra. I am dealing with the integrated rate law, but my question is purely algebraically in nature. I hope, somebody can help me. 1) ln(A) = -kt+ln(B) solve for t solve for k solve ...
Monday, May 13, 2013 at 10:33pm by Yasemine

Science(Chemsitry)
HNO3 used as a reagent has specific gravity of 1.42g/ml and contains 70% by strength HNO3. Calculate a)Normality Of Acid b)Volume of acid that contains 63g pure acid c)Volume of water required to make 1N solution from 2ml conc.HNO3
Thursday, June 16, 2011 at 2:43am by Atul

Chemsitry
During an experiment, a student adds 1.23 g of CaO to 200.0 mL of 0.500 M HCl. The student observes a temperature increase of 5.10 C. Assuming the solution\'s final volume is 200.0 mL, the density if 1.00 g/mL, and the heat capacity is 4.184 J/(gC), calculate the heat of ...
Wednesday, June 26, 2013 at 12:33am by imstupid

chemsitry
hi I need help with this question please. 1. consider the decomposition of N2O5 in carbon tetrachloride(ccl4) at 45c 2N2O5(soln)-> 4NO2(g)+ O2(g) The reacion is first order in N2O5, with the specific rate constant 6.08*10^-4 per second.calculate the reaction rate under ...
Tuesday, December 8, 2009 at 6:45pm by hrithik

Chemsitry
You want 25 mL of 0.1M; that is mols = g/molar mass = ? You want to convert half of that to the acid; therefore, 1/2 x mols tris = ? Now, M HCl = mols HCl/L HCl. You kow M and mols, solve for L HCl and convert to mL.
Monday, April 2, 2012 at 11:39pm by DrBob222

Chemsitry - Van Der Waals
The constants "a" and "b" in the van der waals equation are "empirical coefficients". What exactly does that mean? Show that the units for "a" and "b" are appropriate for the the Van der Waals equation?
Wednesday, September 19, 2012 at 3:13pm by Indi

Chemsitry
Stomach acid is essentially 0.10 M HCl. An active ingredient found in a number of popular antacids is CaCO3. Calculate the number of grams of CaCO3 needed to exactly react with 250 mL of stomach acid. CaCO3(s)+ 2HCl(aq)= CO2(g)+ CaCl2(aq)+ H20(l)
Tuesday, November 13, 2012 at 6:12pm by Brit

Chemsitry
When 3.75 g of a nonelectrolyte solute is dissolved in 405 mL of water at 25 C, the resulting solution exerts an osmotic pressure of 897 torr. What is molarity? I found molarity to be 0.048. What is the number of moles of solute? to find moles, I multiplied it by .405 and got...
Friday, March 1, 2013 at 11:08pm by Anonymous

chemsitry
Perhaps a typo. Tetrahedral is sp3. http://en.wikipedia.org/wiki/Phosphoryl_chloride
Wednesday, December 11, 2013 at 3:36pm by DrBob222

Chemsitry
For the following equilibrium process: CO2 + H2 = CO + H2O The equilibrium concentrations of reacting species are: [CO]= .050 M; [H2]= .045 M; [CO2]= .086 M; [H2O]= .040 M. (a) Calculate Kc for the reaction (b) If we add CO2 to increase its concentration to 0.50 mol/L, what ...
Saturday, August 16, 2008 at 9:08pm by Ronnie

chemsitry
1)100ml sample of solution that is 0.2M in both Naf and Hf has 4.0 ml of 1.0M hcl added to it. calculate the ph change of this soultion .ka =7.2*10^-4 2)40 ml of 0.32M benzoic acid if titrated with 60 ml of 0.2 M naoh. clacilate the ph of the resulting solution at the ...
Sunday, March 4, 2012 at 7:24pm by Anonymous

Chemsitry II
The energy absorbed by the calorimeter itself is constant x delta T = 10 x 10. The energy absorbed by the calorimeter AND the contents is [mass soln x specific heat soln x delta T] + [Ccal x delta T}= ??
Tuesday, May 31, 2011 at 9:07pm by DrBob222

Chemsitry Nits
I lent my sleeping bag to a co-worker once, when I used it the next night I woke up suddenly, feeling something crawling in my crotch. I spent the next 2 hours picking the critters off. then I went cross eyed picking nits. I got them all. Unpicked nits can grow into a HUGE ...
Sunday, March 17, 2013 at 9:53pm by Ken

CHEMSITRY
IN THIS EXPERIMENT YOU FILL A PREFROM WITH WATER AND PUT A DRINKING STRAW INTO THE PREFROM AND USE CLAY TO SEAL THE OPENING. It is important to recall that when you first tried it, you were unable to drink, but a small amount of water entered the straw. When the water goes ...
Thursday, May 20, 2010 at 12:17pm by POPCORN

Chemsitry==> Dr. Bob222
I understand. That is why I worked on a problem and developed a headache when I couldn't figure out why the answer doubled compared to the answer that I calculated. If I set up the way that you mentioned then I would not have ran into that problem, and I can prevent others ...
Sunday, March 17, 2013 at 9:53pm by Devron

Chemsitry II
50.00 mL of 1.0 M HCl and 50.00 mL of 1.0 M NaOH are mixed. The temperature is observed to increase by 10.0 degrees C. How much energy (in J) was absorbed by the calorimeter? Assume a density of the reaction mixture of 1 g/mL. Specific heat of the solution is 5.00 J/g/degree C...
Tuesday, May 31, 2011 at 9:07pm by Sarah

Chemsitry
The Ksp of PbBr2 is 6.60 10^6. What is the molar solubility of PbBr2 in pure water? What is the molar solubility of PbBr2 in 0.500 M KBr solution? What is the molar solubility of PbBr2 in a 0.500 M Pb(NO3)2 solution?
Sunday, March 17, 2013 at 9:53pm by Anon

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