Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

How much would the concentration of CO2(aq) change due to a temperature change from 25°C to 26°C at 1atm?

I was having a little trouble posting this question, sorry

Any help would be greatly appreciated, thanks

2 Answers

Relevance
  • 7 years ago
    Favorite Answer

    Whoa! Back the boat up. While there seems to be a lot of work there, N3...'s solution makes no sense. He is calculating the moles of GAS in 1 L of CO2 at 298K and 1 atm. That isn't the amount that is dissolved in SOLUTION at 298K.

    The amount of CO2 dissolved in water can be determined from Henry's law.

    c = kH(p) ..... c is the concentration of the gas, kH is the Henry's law constant for the particular gas and p is the partial pressure of the gas above the solution.

    c = 0.034 mol/Latm x 1.00 atm = 0.034 mol/L

    The Henry's law constant varies with temperature, and must be calculated at the new temperature.

    kH(T) = kH(T') x e^(C(1/T - 1/T')) .... where T is the new temperature, T' is 298K, C is a constant for each gas. For CO2, C = 2400

    kH(T) = 0.034 mol/Latm x e^(2400(1/299 - 1/298))

    kH(T) = 0.033 mol/Latm

    Calculating the concentration at 26C....

    c = kH(p)

    c = 0.033 mol/Latm x 1.00 atm = 0.033 mol/L

    The concentration will decrease by 0.001 mol/L as the CO2 solution goes from 25C to 26C.

  • 7 years ago

    PV = nRT

    n = PV/RT

    P = 1atm

    R = 0.08205746 Latm/Kmol

    T1 = 25C + 237.15K = 298.15K

    T2 = 26C + 237.15K = 299.15K

    n = PV/RT

    n = 1atm(1L)/(0.08205746 Latm/Kmol)(298.15K)

    n = 1/24.465mol

    n = 0.0409mol CO2 --- initial mass of CO2

    n = 1atm(1L)/(0.08205746 Latm/Kmol)(299.15K)

    n = 1/24.547mol = 0.0407mol CO2 -- final mass of CO2

    dm = mf - mi

    where,

    M = m/V

    M = 0.0409mol/L = 0.0409M <--- Molarity of CO2 at 25C

    M = 0.0407mol/L = 0.0407M <---- Molarity of CO2 at 26C

    dM = Mf - Mi = 0.0407M - 0.0409M = -0.0002M <---- change of CO2 when T is increased by 1C

    therefore,

    ----- The concentration of CO2 is decreased by about 0.0002M when the temperature is increased from 25C to 26C. The final concentration of CO2 at 26C is 0.0407M.

Still have questions? Get your answers by asking now.