Last modified: Thu 07/28/2016 09:52:22 am
BCE

Oklahoma State University

It is OK to use your textbook, but if you can answers the questions without it that is OK too.

Do not press the RETURN or ENTER key while you are answering these questions. Your browser will interpret either the same as clicking on the Submit key.

Answer all of the questions below. If you do not know an answer enter CNA. However, it will help me the most if you answer each question with your best intuition/idea about what would be a reasonable answer.


First Name:

Last Name:

School:

To answer the questions in the BCE we will use a new simulation currently being developed in collaboration with Pearson Publishing to perform a calorimetry experiment. (NOTE: when you click on the link for the simulation will be opened in a new window. You will see a page with three tabs. We want the Experiment tab. You are welcome to look at the contents in the other tabs. In the Experiment tab you should select the Run Experiment button. You are welcome to click on the Demonstration button if you wish. )

In the experiment you will investigate what happens when a sample of NaOH is added to water.

Procedure:

1) Beneath the beaker on the left, select the solid tab and then select NaOH from the popup list of solids.

2) Use the slidebar to add 2.00 g of NaOH to the beaker. Set the temperature of the solid to 20 degrees Celsius.

3) Beneath the beaker on the right (the calorimeter) select water from the popup list of liquids.

4) Use the slidebar to measure 50 mLs of water and set the temperature of the water to 20 degrees Celsius.

5) Enter the data in the table below, then click the Start button on the lower right portion of the page.

calorimetry experiment

1. Complete the table with the important experimental information;

Mass of NaOH

grams

Mass of water

grams

Initial temperature of water

˚C

Final temperature of solution

˚C

2. What was the change in temperature experienced by the solution?

˚C

3. Calculate the amount of heat the solution absorb? (NOTE: Remember the specific heat of water? We'll assume the specific heat of the solution and the specific heat of water are the same in this experiment. In this problem the mass in the equation q = mass*SH*T should be the mass of the NaOH plus the mass of water. This is because the NaOH dissolves in the water and the solution absorbs the heat.)

Joules

4. In your experiment, what caused the solution to warm up?

5. The heat you calculated in Q3 was for the mass of NaOH that you measured. Calculate the heat released by the addition of 1 mol of NaOH to the sample of water.

Joules

6. In the simulation there is a checkbox 'Show Microscopic View'. Click on that checkbox and repeat the experiment to explore what happens when the sample of NaOH dissolves in water. Briefly describe what happens when sodium hydroxide dissolves in water, as viewed at the microscopic or particulate level.

7. Is there anything about the questions that you feel you do not understand? List your concerns/questions.

8. If there is one question you would like to have answered in lecture, what would that question be?