Friday, Nov. 2nd: “A” DayMonday, Nov. 5th: “B” Day

AgendaHomework Questions/problems Sec 10.4 Quiz: “Order and Spontaneity”Lab Discussion/write-up: “Calorimetry and

Hess’s Law”Movie: “Heat”Concept review work time…Lab next time: dress appropriately!

Sec. 10.4 reviewPg. 367: #3-5, 7-11

Questions?

Problems?

Hand in

Sec 10.4 Quiz“Order and Spontaneity”

You can use your notes, your book, and a lab partner of your choice to complete the quiz…

Good Luck!Pick up a copy of the lab when you hand in

your quiz and start reading it through…

“Calorimetry and Hess’s Law”Discussion

Remember, Hess’s Law states that we can find the enthalpy change for a reaction by adding up the enthalpy changes for the individual steps.

You will run 3 different reactions: 1.NaOH (s) + H2O (l)

2.NaOH (aq) + HCl (aq)3.NaOH (s) + HCl (aq)

**(The 1st 2 reactions add up to give the 3rd)**

“Calorimetry and Hess’s Law”Discussion

You will use the calorimetry equation q = mCΔT to calculate the heat released in each

reaction.You will then use stoichiometry and the

calorimetry equation to calculate find out if the temperature did indeed get hot enough to burn the man.

“Calorimetry and Hess’s Law”

PurposeWhat is the purpose of this lab?

The purpose of this lab is to measure the amount of heat released by mixing NaOH and HCl to find out if enough heat is released to raise the temperature high enough to cause a burn.

“Calorimetry and Hess’s Law”Materials

There are a few changes to the materials list:We will NOT be using the 3 items listed under

“Optional Equipment”We will be using calorimeters, NOT plastic foam

cupsYou will use a porcelain scoop instead of forceps

when handling the NaOH.Changes to material list have already

been made!

“Calorimetry and Hess’s Law”Procedure

The procedure for this lab is a little confusing because the original lab handout showed 2 different ways of running the lab.

Your procedure starts on the top of pg. 36 where it says “Advance Preparation”, steps #1 and #2.

The rest of page 36 is crossed out because you will be using the “Thermometer Procedure” that begins on pg. 39.

Lab Discussion: “Calorimetry and Hess’s Law”

There are 3 different reactions you will be running, all using hydrochloric acid (HCl) and sodium hydroxide (NaOH).

You do not have to wear gloves when handling the NaOH, but you must use the porcelain scoop to measure them. Do not touch the pellets!

Be sure to CLOSE the NaOH container when done measuring it because it is hygroscopic , meaning it will absorb moisture from the air and gain mass.

Lab Discussion: “Calorimetry and Hess’s Law”

When you add the chemicals to the calorimeter, make sure you add them to the beaker and NOT directly into the metal calorimeter container.

These chemicals are corrosive and will pit the metal calorimeters.

The actual laboratory part of this lab is not difficult, it’s the calculations that will take some time.

We will go through the calculations together back in the classroom.

Lab Write-Up: “Calorimetry and Hess’s Law”

Be sure to update your table of contents with this lab.

You have the rest of the period to complete the lab write-up with your lab partner:

1. Title2. Purpose3. Hypothesis4. Materials5. Procedure6. Reflection Statement

Movie: “Heat”

You DO NOT have to takenotes on the movie, but I doexpect you to pay attention!