Recent content by sciencegem

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    Acidity of Isobutane: pKa Value & Kb Calculation

    Homework Statement Don't want to give too many details, but a homework question gives a pKa value for isobutane (CH3)3CH as 71. I'm obviously missing something because when I try to calculate Kb out of curiosity I get an astoundingly large value (especially considering I don't even see how...
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    Rate of Reaction: Solving to Find Time for [A] to Reach X Conc.

    Awesome thanks! Confused by what you mean when you say that's wrong for second order though, you mean 1/[A]=1/[A_0] +kt? I'm pretty sure that's what my textbook says it is.
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    Rate of Reaction: Solving to Find Time for [A] to Reach X Conc.

    My reasoning now is Rate=k[A][ B] when [A] halves, [ B] halves, and the rate is effected by a factor of 1/4, so I can determine different concentrations of [A] at different times using the second order integrated rate law 1/[A] = 1/[A_0] + kt. Where's the flaw in that reasoning?
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    Rate of Reaction: Solving to Find Time for [A] to Reach X Conc.

    Nope actually, I was so close but I'm still a little confused:frown:. Is that different simplification you were referring to that the rate law can basically be written Rate=k[A]^2... or can it? How does that make physical sense?
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    Rate of Reaction: Solving to Find Time for [A] to Reach X Conc.

    Ahh, I get it now. The concentrations are similar which makes a lot more sense. Thank you so much for all you help!
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    Rate of Reaction: Solving to Find Time for [A] to Reach X Conc.

    I think I get it! Thank you! So it's a second order reaction, but I can still just punch in the concentration of A into the integrated rate law for second order reactions, because A is behaving second order. Is that correct?
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    Rate of Reaction: Solving to Find Time for [A] to Reach X Conc.

    Thank you so much, that's really helpful. It's not a pseudo-first reaction. I just want to double check how you know it's first order? was having trouble editing, so I typed Rate=k[A] first but I mean Rate=k [ A ] [ B ]. Isn't that a second order reaction? When you say "But even when this is...
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    Rate of Reaction: Solving to Find Time for [A] to Reach X Conc.

    It won't let me edit it! I meant Rate=k*[A]*B. (For some reason whenever I put the B in square brackets it won't save...).
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    Rate of Reaction: Solving to Find Time for [A] to Reach X Conc.

    Homework Statement [/B] I don' t want to be too specific, but it's basically "A + B -> C has the rate law Rate=k[A][ B], How long does it take [A] to reach concentration X. K is given and the initial concentrations of A and B are given." Homework Equations The integrated rate laws, whether I...
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    A "neat set of reactions" that makes fuel on Mars

    Thanks for all the input guys! I'll look up benzene syntheses. Also for any future readers of this thread I found this very interesting: http://web.stanford.edu/~cantwell/Recent_publications/Boiron_AIAA_2013-3899.pdf
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    A "neat set of reactions" that makes fuel on Mars

    Thanks guys! Never thought of hydrogen peroxide...I'm assuming the oxygen would come from the carbon dioxide in Mar's atmosphere? Where'd the carbon go?One reaction I found would produce carbon monoxide and oxygen, and if I've calculated things right there'd be more than 13kg of carbon monoxide...
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    A "neat set of reactions" that makes fuel on Mars

    Hi, I'm reading The Martian by Andy Weir (fantastic book). A character, describing how a Mars mission works, says of fueling their ascent vehicle: "Through a neat set of chemical reactions with the Martian atmosphere, for every kilogram of hydrogen you bring to Mars, you can make thirteen...
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