Chemistry

Calculate the entropy change in the surroundings when 1.00 mol N2O4(g) is formed from 2.00 mol NO2(g) under standard conditions at 298 K.

I get +192 J/K. The book says -192 J/K. Here is my work, where am I going wrong?

Standard Enthalpy of NO2(g) = 33.18 kJ/mol * 2 mol = 66.36 kJ
Standard Enthalpy of N204(g) = 9.16 kJ/mol * 1 mol = 9.16 kJ
q(sys) = Enthalpy change = 9.16 kJ - 66.36 kJ = -57.2 kJ
q(sur) = -q(sys) = +57.2 kJ
Delta S(sur) = q(sur)/T = +57.2 kJ / 298 K = +192 J/K

  1. 👍
  2. 👎
  3. 👁
  1. you got qsystem and qsurr confused. qsurr is your change in enthalpy: -57.2KJ and qsy is +57.2 KJ

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. chemistry

    3. Calculate the standard entropy change for the reaction: N2 + 3H2 → 2NH3 given the standard entropies Sº(N2)(g) = 191.6 J K^-1 mol^-1 Sº(H2)(g) = 130.6 J K^-1 mol^-1 Sº(NH3)(g) = 193.3 J K^-1 mol^-1

  2. Chemistry

    Identify each enthalpy change by name and classify each change as exothermic or endothermic. a)1 mol C3H8 (l) ==> 1 mol C3H8 (g) b)1 mol Hg (l) ==> 1 mol Hg (s) c)1 mol NH3 (g) ==> 1 mol NH3 (l) d)1 mol NaCl(s) + 3.88kJ/mol ==> 1

  3. CHEM

    Calculate ΔSfus and ΔSvap for HF. Determine the entropy change when 7.60 mol of HF(l) freezes at atmospheric pressure. I already calculated ΔSfus as 24.103 J/k*mol and ΔSvap as 86.07 J/K*mol....These are correct (I checked

  4. chemistry

    Dinitrogen tetroxide decomposes to form nitrogen dioxide in a second order reaction: N2O4(g)-> 2NO2(g) At 400K, the rate constant for this reaction has been measured to be 2.9x10^8 L/mol*s.suppose 0.222 mol of N2O4(g) is placed in

  1. ap chem

    calculate the lattice enthalpy of potassium fluoride from the following data: enthalpy of formation of K(g): +89 kJ · mol−1 first ionization energy of K(g): +418 kJ · mol−1 enthalpy of formation of F(g): +79 kJ · mol−1

  2. chem

    Use bond energies to estimate the enthalpy change for the following reaction C2H2 + H2-> C2H4 i figured the bonds broken are: 1 C triple bond C 1(812kj/mol) 2 C-H 2(414kj/mol) 1 H-H 1(435kj/mol) Bonds formed 1 C=C 1(590kj/mol) 4

  3. AP Chemistry

    Calculate the standard entropy change for the dimerization of NO2: 2NO2(g)→N2O4(g)at 298 K, if S◦ ∆H◦f J/K·mol NO2(g) 240.06 33.18 N2O4(g) 304.29 9.16 Answer in units of J/K·mol

  4. chemistry

    Calculate the change in entropy that occurs in the system when 1.49 mol of acetone (C3H6O) condenses from a gas to a liquid at its normal boiling point (56.1 ∘C) The heat of vaporization is 29.1 kJ/mol.

  1. chemistry, please help

    2NO2(g)--> 2NO(g) + O2(g) , H=+114.2kJ (Note: H, S, G all have a degree sign next to them) NO: H(enthalpy)=90.3kJ/mol, S(entropy)=210.7J/mol*K, G(gibbs energy)=86.6 O2: H(enthalpy)=0, S(entropy)=?, G(gibbs energy)=0 kJ/mol NO2:

  2. CHEMISTRY

    Calculate the change in entropy that occurs when 17.68 g of ice at -12.7°C is placed in 54.05 g of water at 100.0°C in a perfectly insulated vessel. Assume that the molar heat capacities for H2O(s) and H2O(l) are 37.5 J K-1

  3. Chemistry

    The standard molar Gibbs free energy of formation of NO2 (g) at 298 K is 51.30 kJ · mol −1 and that of N2O4 (g) is 97.82 kJ · mol −1 . What is the equilibrium constant at 25 ◦ C for the reaction 2 NO2(g) N2O4(g) ?

  4. Chemistry Class

    Dinitrogentetraoxide partially decomposes according to the following equilibrium: N2O4 (g) -> 2NO2 (g)

You can view more similar questions or ask a new question.