Chemistry-Thermochemistry (grade 12)

posted by .

A 65.0 g sample of 0.600 M HI at 18.46 degrees celsius is added to 84.0 g of solution containing excess KOH, also at 18.46 degrees celsius. The final temperature is 21.96 degrees celsius. Calculate the enthalpy of H for the reaction.

Assume the specific heat of the solution is 4.184 J/g(degrees celsius), and the calorimeter has negligible heat capacity .

HI(aq) + KOH(aq) --> KI(aq) + H2O(l)

enthalpy of H ?

  • Chemistry-Thermochemistry (grade 12) -

    You have 65.0 g soln from HI and 84.0 g H2O with the KOH so total mass soln is 149 g.
    q = mass H2O x specific heat water x (delta T).

    USUALLY delta H for a reaction is done in kJ/mol. This problem has no easy way to get to moles but q/mol = J/mol and you can convert that to kJ/mol if needed. If you assume the density of the HI solution is 1.00 g/mL, that can be used to solve for mols HI; e.g., 65 mL of 0.600 M HI would be moles = M x L = 0.600 x 0.065 = ? and you can use that for mols. I doubt that the density is 1. g/mL.

  • Chemistry-Thermochemistry (grade 12) -

    Awesome

    I am defiantly starting to understand this stuff better.

    .065L x (.600 mol/L) = 0.0390 mol

    q=MC(delta T)
    = 149g x 4.184 J/g(C) x 3.5 celsius
    = 2181.9 J
    =2.2 kJ

    Then I did
    2.2 kJ / 0.0390 mol
    = 56 kJ/mol

    for my final answer I got 56 kJ/mol

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Chemistry

    A 5.0-g Sample of KBr at 25.0 degrees celsius dissolves in 25.0 degrees celsius 25.0 mL of water also at 25.0 degrees celsius. The final equilibrium temperature of the resulting soltution is 18.1 degrees celsius. What is the enthalpy …
  2. Chemistry

    Calculate the joules of energy involved when 11 grams of water at 10.0 degrees Celsius cools and then freezes at 0.0 degrees Celsius. How many kilocalories are required to raise the temperature of 305 gtams silver from 30 degrees Celsius …
  3. Chemistry

    A 50g sample of metal was heated to 100 degrees Celsius and then dropped into a beaker containing 50g of water at 25 degrees Celsius. If the specific heat of the metal is .25 cal/g degrees Celsius, what is the final temperature of …
  4. Chemistry

    A 100g sample of water at 90 degrees celsius is added to a 100g sample of water at 10 degrees celsius. The final temperature of the water is which of the following: a) between 50 degrees celsius and 90 degrees celsius b) 50 degrees …
  5. chemistry

    Calculate the enthalpy change for converting 10.0g of ice at -25 degrees Celsius to water at 80 degrees Celsius. The specific heats of ice, water, and steam are 2.09j/g degrees Celsius, 4.18j/g degrees Celsius, and 1.85j/g degrees …
  6. Chemistry

    A 5.0g KBr sample, at 25 degrees celsius, dissolved in 25 ml of water, also at 25 degrees celsius. the final equilibrium temperature of the resulting solution is 18.1 degrees celsius, What is the enthalpy change in J/g and KJ/mole …
  7. Chemistry

    When 100 mL of Ba(NO3)2 solution at 25 degrees Celsius is mixed with 100 mL solution CaSO4 solution at 25 degrees Celsius in calorimeter, the white solid BaSO4 forms and the temperature of the mixture increases to 28.1 degrees Celsius. …
  8. Chemistry

    A 5.0-g Sample of KBr at 25.0 degrees celsius dissolves 25.0 mL of water also at 25.0 degrees celsius. The final equilibrium temperature of the resulting soltution is 18.1 degrees celsius. What is the enthalpy of of solution in kilojoules …
  9. Physics 20

    1. How much heat energy is required to change 500 grams of water at 100 degrees Celsius to steam at 100 degrees Celsius?
  10. chemistry

    a 2.00g sample of zinc metal is added to a calorimeter containing 150g of nitric acid solution initially at 20.0 degrees celsius . The temperature of the solution increased to 28.0 degrees celsius . Calculate the delta H of the reaction …

More Similar Questions