A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 4 years ago

‎50.mL of 0.20M lead (II) nitrate solution, Pb(NO3)2(aq), at 19.6C was added to 30mL of a solution containing excess potassium iodide, KI(aq) also at 19.6C. The solutions reacted to form a yellow lead (II) iodide precipitate, PbI2(s), and the temperature of the reaction mixture increased to 22.2C. Calculate the enthalpy change per mole of lead (II) nitrate for the reaction.

  • This Question is Closed
  1. anonymous
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    How do we know if the reaction is endothermic or exothermic?

  2. JFraser
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Second question first, since it's easier: The temperature of the reaction increased, so energy must have been released. That tells us whether it is endothermic or exothermic. First question: The total amount of energy released will be equal to:\[Q = m*C{_P}* \Delta T\] where m is the total mass of water, C is the specific heat of water (4.18J/gC) and DT is the temperature change. The energy released PER MOLE of Pb(NO3)2 will be equal to the total energy change divided by the number of moles present in the lead (II) nitrate solution you started with:\[Q/mol = \frac{Q}{0.050L * (\frac{0.20mol}{1L})}\]

  3. anonymous
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Thank you :)

  4. anonymous
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Final answer I got is -85kJ.

  5. anonymous
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    -87*

  6. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.