Total # Posts: 135
I am reviewing my test and I having trouble figuring out the answer to the following question: List the following element symbols in order of decreasing exothermic electron affinity: Al, Ca, As _______>________>________ I wrote: Al>As>Ca (I got it wrong) I know ...
March 6, 2010
What mass of CsBr must be added to .500L of water to produce .4molality solution? What are mole fraction and mass percent? Here is my work and below I will post a question about it: 1 mol CsBr = 212.81g density of water = 1g/mL d=mv 1=x/500 x=500g of water --> solvent ....
February 18, 2010
1) How many drops of 12M HCl would you add to 1.00 L of 0.100 M HC2H3O2 to make [C2H3O2-] = 1.0 x 10^-4 M? Assume that 1 drop = 0.050 mL and that the volume of the solution remains 1.00 L after the 12 M HCl is diluted. [Hint: What must be the [H3O+] in the solution?] 2. What ...
August 10, 2009
What mass of Al can be deposited by the passage of a constant current of 5.00 A through a Al(NO3)2 solution of 2.00 hours? My work: Q= I*t = 5 * 7200sec = 36000 36000/96458= .3732 .3732* 1/3 * (26.98*3) = 10.06g But this is wrong it's suppose to be 3.3.6g. why is that?
August 9, 2009
Consider a system consisting of a cylinder with a movable piston containing 10^6 gas molecules at 298K at a volume of 1L. Consider the following descriptions of this system: 1. Initial system 2. Starting from the initial system, the volume of the container is changed to 2L and...
March 16, 2009
You need to produce a buffer solution that has a pH of 5.08. You already have a solution that contains 10 mmol (millimoles) of acetic acid. How many millimoles of acetate (the conjugate base of acetic acid) will you need to add to this solution? The of acetic acid is 4.74.
February 28, 2009
complete and balance the following decompition equations CaCO (heated) --> 3 please tell me how to do this and what exactly is suppose to be going through my head while doing this. I can balance these equations with no problem I just have no idea what to do...
December 17, 2008
How many atoms are there in 6.90 moles of sulfur (S)? Calculate the molar mass of a compound if 0.411 mole of it has a mass of 185 g. Know of any good sites that help answer these ? Or information on how to?
September 15, 2008
N2 + 3H2 --> 2NH3 At 25°C (delta)Ho = -92.22 kJ and (delta)So = -198.53 J/K. Using this information, calculate the equilibrium constant for the reaction at 2.43x10^2°C. (R = 8.314 J/K) Apparently the way I'm doing it is wrong: I divide 198.53 by 1000 then ...
November 17, 2007
Calculate the heat of reaction for the incomplete combustion of 67.0g propane producing carbon monoxide gas and water vapour. how would I go about and do this question? What are you studying? Do you know how to use the thermodynamic tables (delta Ho, etc). delta Hrxn = delta ...
May 14, 2007
whats relationship between temp and kinetic energy http://www.google.com/search?as_q=temperature+kinetic+energy+&hl=en&num=10&btnG=Google+Search&as_epq=&as_oq=&as_eq=&lr=&as_ft=i&as_filetype=&as_qdr=all&as_nlo=&as_nhi=&as_occt=title&as_dt=i&as_sitesearch=&as_rights=&safe=images
March 7, 2007