Last modified: Sun 01/17/2016 03:43:01 pm
BCE

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:

1. When the white solid, NaCl, is added to water describe what happens. You may use some or all of the following words in your decription: soluble, ions, molecules, particles, solvent, hydration.

Which one of the following representations best depicts/supports your understanding/model of NaCl dissolved in water?

a) b) c) d)

Briefly explain what features of the representation you picked that support your understanding of what happens when NaCl dissolves in water.

2. Write a balanced chemical equation that supports your choice above.

3. Briefly explain what the terms nonelectrolyte means to you.

4. Briefly explain what the terms strong electrolyte means to you.

5. On the basis of your explanations in Q3 and Q4, does NaCl behave as a strong electrolyte or as a nonelectrolyte when it is added to water?

6. Write a chemical equation that symbolically (using correct chemical formulas) represents what happens when NaCl dissolves in water.

7. According to your chemical equation in Q6 for every mole of NaCl dissolving how many moles of particles are produced?

8. Based on the Experiment that you performed in an earlier BCE, the following data was obtained;

Exp.

solute

Solvent

mass of solute (g)

mol of solute (mol)

mass of solvent (g)

molality of solution (m)

Freezing point of solution (°C)

1

sucrose

water

10.0 g

0.029

100. g

0.29

-0.50

2

sodium chloride

water

1.7 g

0.029

100. g

0.29

-1.0

3

calcium chloride

water

3.2 g

0.029

100. g

0.29

-1.5

How would you explain the freezing point depression experienced in the three experiments?

 

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

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