# Posts by helllp

Total # Posts: 9

mathematics
expand [e+1/e]^4 in terms of e. express [e+1/e]^4 + [e-1/e]^4 as the sum of three terms. please help

math
Consider the expansion of (x + 2)11. (a) Write down the number of terms in this expansion. (b) Find the term containing x2.

Chemistry
Carbon dioxide dissolves in water to form carbonic acid, which is primarily dissolved CO2. Dissolved CO2 satisfies the equilibrium equation CO2(g) <-> CO2(aq) K=0.032 The acid dissociation constants listed in most standard reference texts for carbonic acid actually apply...

Chemistry
How can I rank these substrates from fastest to slowest reacting? In an SN2 reaction with NaI-Acetone? Based on theory alone? benzyl chloride n-butyl bromide n-butyl chloride sec-butyl chloride tert-butyl chloride

Chemistry
I also have the density of the distillate. I don't know what the initial and final purity of the mixes is, we were just told we were distilling "unpurified" acetone.

Chemistry
Information: -mass (of both unpurified and purified acetone) -volume -boiling point temperature (not sure if that's relevant)

Chemistry
Yes, I have the volume of the purified acetone

Chemistry
I know the initial volume of unpurified acetone (before distillation) and the final volume of acetone (after distillation)

Chemistry
I did a simple distillation and a fractional distillation to purify acetone. How do I determine the concentration of acetone? (Instructions say this is not a simple M=mol/L calculation). My guess was to divide the volume of purified acetone by the volume of unpurified acetone...