Recent content by vaazu

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    Setup Thermodynamic Cycle for Enthalpy of Hydration of Mg2+ Ions

    yeah, the solvation enthalpy, from solid to liquid, then the enthalpy of Cl- in the solution. The change of the enthalpy in the cycle should be 0, but how to find the difference in the MgCl2(s) and the gas phases?
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    Setup Thermodynamic Cycle for Enthalpy of Hydration of Mg2+ Ions

    Homework Statement Set up thermodynamic cycle for determining the enthalpy of hydration of Mg2+ ions The following enthalpies are given Sublimation of Mg ionization energies of Mg dissociation enthalpy of Cl2 electron gain enthalpy of Cl enthalpy of solution of MgCl2(s) enhalpy of...
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    Gas is isothermally and reversibly condensed

    Homework Statement gas is isothermally and reversibly condensed n=2(mol) T=337K H(vap)=35.3kJ/mol find w, q, U, H Homework Equations The Attempt at a Solution H=-H(vap)*2=-70.6kJ/mol H=U+n(g)RT w=-n(g)RT n(g)=-2 w=5.6kJ So U=H-w U Should be -70.6-5.6=-76.2, but the book...
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    How Do You Calculate the Dipole Moment of CO2 with a 120 Degree Bond Angle?

    Homework Statement r-bond length (in anströms) q-charge (in debyes) CO2 r(CO)=1.1867 q(C)=1.1352 q(O)=-0.5676 angle between them is 120 deg Homework Equations The Attempt at a Solution I know I have to make vectors and then add them, but I don't know how to make the vectors. I...
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    Salt crystal forms after 3 days of evaporation

    i think you don´t have to divide the sum of atoms by 2 to get the number of Na+ or Cl- atoms, because if you have, let's say 1mole of NaCl, then it has 1mole of Na+ and 1mole Cl- atoms, which means twice as many particles as in NaCl.
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    Cl-C-Cl vs H-C-H Bond Angles in CH4 & Dichloromethane

    Chlorine has three free electron pairs, hydrogen has none. Because of the electon pairs chlorine atoms repell from each other more strongly so the Cl-C-Cl bond angle should be bigger than H-C-H. I am not sure of this, but it seemed logical to me.
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    Silicon vs. Carbon: Exploring the Unlikelihood of Silicon-Based Life

    But if we would assume that the pressure and temperature wouldn´t be the same in the other enviroment. Then could Si compounds be more stable? And the oxidizer (i hope it´s like that in english) wouldn´t be O. For example F. Then SiF4 (it should be a gas) could play the role as CO2. Or is F so...
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    Silicone Super Ball: Learn About Its Properties & Chemistry

    Is the polymer atactic? if it is, how can it be achieved, probably can't be explained in a simple way? what properties would it have if it were for example isotactic?
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    Silicone Super Ball: Learn About Its Properties & Chemistry

    Hello, I have some questions about the "Silicone super ball". Heres a link for it [PLAIN]www.flinnsci.com/Documents/demoPDFs/Chemistry/CF0758.50.pdf[/URL] I have to make a presentation about it so I need to educate myself on the topic. When the solution is mixed a new polymer forms...
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    Electrochemistry; redox potential

    Yes the J was typo, it should be I. Don´t know what was I thinking. Could you explain me, how the Eo is calculated, or what should I be looking for? Is the reaction standard potential calculated between the pair which actually exchanged electrons Cr(3+) and I2, or somehow between the chrome and...
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    Electrochemistry; redox potential

    Homework Statement I have to calculate the redox potential of this equation: Cr2(SO4)3 + 4K2SO4 + 3J2 +7H2O <=> K2Cr2O7 + 6KJ +7H2SO4 I used the nernst equation to calculate the potentials of 2Cr(3+)+7H2O -> Cr2O7(2-) +14H(+) +6e(-) and I2 +2e(-) ->2J(-) which were -1.42V and 0.51V, all...
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    What is the empirical formula of this compound help?

    10.34/16 < 18.53/23 and 25.87/32, but you have more O atoms in your formula than Na and S. How is that? I got Na5S5O4*22H2O, but that's probably not right.
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    Standard gibbs reaction energy

    Homework Statement Write the half-reactions and the overall reaction for the oxidation of water by F2. Determine the standard potential and DeltaGr(0). Homework Equations I can manage the half-reaction and the overall reaction should be: 2 H2O + 2 F2 = 4 HF + O2 The Attempt at a...
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    Difference in simple and fractional distillation

    I found on the internet that fractional is used when the differences in boiling points are below 25C, and that there are more than 2 or 3 substances in the mixture, but i didn´t figure out what's the difference in apparatus or how the substances are purified in fractional distillation. Could...
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    Balancing equation in basic solution

    [SOLVED] balancing equation in basic solution Homework Statement The alkaline solution of hypochlorite ions reacts with solid chromium(3)hydroxide to produce aqueous chromate ions and chloride ions. Write the net ionic equation for the reaction.Homework EquationsThe Attempt at a Solution bone...
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