Wednesday
May 4, 2016

Posts by yoo

Total # Posts: 27

Chemistry
calculate the ph 25.00 mL solution of 0.125 M acetic acid (Ka= 1.75 x 10^-5) after the addition of each of the following volumes of 0.100 M KOH: 10.00 mL, Vep and 35.00 mL
April 21, 2013

calculus
To find the concavity just graph it or use the first derivative and pick values greater than, or less than your critical points see if those values are positive or negative. IF positive, the graph will concave up, if negative - concave downwards. To find the points of ...
November 11, 2012

bio
Supercoiling of DNA can occur (choose all that apply): A. when double stranded DNA is overwound B. when double stranded DNA is underwound C. when double stranded DNA is heated above it's Tm D. when DNA is treated with nucleases and Generally, cellular DNA is: A. Slightly ...
April 4, 2011

bio
Supercoiling of DNA can occur (choose all that apply): A. when double stranded DNA is overwound B. when double stranded DNA is underwound C. when double stranded DNA is heated above it's Tm D. when DNA is treated with nucleases and Generally, cellular DNA is: A. Slightly ...
April 4, 2011

organic chem
what are some chemical reasons that might have resulted in a lower yield of a product on a grignard reaction. Something related to grignards being very reactive and since its the limiting reagent, any reaction that destroys it will result in a hit in yield.
February 28, 2011

calc
f(x)=3x^ln(x), find f '(9). i can't find the answer :( I got 3x^lnx(((ln(lnx))/x)+ 1/lnx)
February 18, 2011

calc
f(x)=6(sin(x))^x, find f'(1). and f(x)=3x^ln(x), find f'(9). i tried these so many times and it keeps telling me that my answers are wrong :/ for the first one i did f'(1) = 6sin(1) * {ln[sin(1)] + cot(1)}., is that correct, when i put it in my calculator and put ...
February 18, 2011

chem
what other experiments or techniques can be used in replace of infrared spectroscopy
February 15, 2011

chem
rank strongest acid to weakest acid? rank strongest acid to weakest acid H3CNH2 CH3C (triple bond) CH CH2=CHCH3 H20 CH4 i tried to rank them using the Pka values but I couldn't find the pKa value of the alkyne and I thought the H3CNH2 was the strongest but it's not?
February 15, 2011

math
Find the volume of the solid obtained by rotating the region bounded by the given curves about the specified axis. x=2y^2 , y=1 ,x=0 about the y-axis
January 29, 2011

math
A car drives down a road in such a way that its velocity ( in m/s) at time t (seconds) is v(t)=2t^1/2 +2 . Find the car's average velocity (in m/s) between t=4 and t=9. i really need help with thisss
January 29, 2011

organic chemistry
in gas chromatography, why do E1 and E2 give different peaks (areas) though it's the same compound?? dehydration of a secondary alcohol proceeds readily with the presence of strong acid and proceeds with E1 mechanisms. Removing product from chemical system at equilibrium ...
January 24, 2011

organic chemistry
dehydration of a secondary alcohol proceeds readily with the presence of strong acid and proceeds with E1 mechanisms. Removing product from chemical system at equilibrium shifts the equilibrium in the direction favoring the formation of the products. I carried out a ...
January 24, 2011

organic chemistry
so it is because acidic and basic conditions are used...but I'm still unsure how that gives different product ratios.
January 24, 2011

organic chemistry
in gas chromatography, why do E1 and E2 give different peaks (areas) though it's the same compound?? For example, for 1-butene, the percent composition is low in E1 but very high in E2.
January 24, 2011

organic chemistry
what product is formed from 1-bromo-2 methyl-cyclohexane reaction with CH3ONa and CH3OH...from a substitution reaction ...I got 1-CH3OH-2methly-cyclohexane but it's wrong. Not sure how to do it
January 19, 2011

chem
thank you!
December 3, 2010

chem
standard free energy change of -11.70 kJ mol-1. Calculate equilibrium constant for 25 degrees C. I got 7.772..and it's wrong I did -11700J/ (-2.303 x 8.314 x 298)= 2.0505277 and then e^(2.0505277)= 7.77 I don't know what I did wrong
December 3, 2010

chemistry
I did a lab about melting point. It is asking me for the purity of the compounds? How do I find it? Do I use melting points or percent yield?
October 5, 2010

english
What does relocalization within this text? what does relocalization mean within this text "A sane urbanism has to mean an intense commitment to RELOCOLIZATION, specifically to local economies. It means not spending \$8 billion dollars to expand highway capacity via the ...
September 29, 2010

chemistry
is melting point of 120-126 C a typical range for a melting point
September 28, 2010

chemistry
for oxidation number of Fe(CO)5 I don't understand why Fe is zero
July 27, 2010

chemistry
Describe the electrolysis of an aqueous soln of KNO3
July 27, 2010

chemistry
Tarnished silver contains Ag2S. The tarnish can be removed by placing silverware in an aluminum pan containing an inert electrolyte soln, such as NaCL. Explain the electrochemical principle for this procedure, [The standard reduction potential for the half-cell reaction Ag2S(s...
July 27, 2010

chemistry
A hypothetical diprotic acid has pKa1=5 and pka2=7. Could a buffer at pH6 be prepared with this acid? If so how?
July 27, 2010

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