LEFT SIDE: Physical Science Rate of Melting, Boiling, and Solubility Mini-Lab

Unit 2, Day 7

Name: ______Date: ______LEFT SIDE: Physical Science – Rate of Melting, Boiling, and Solubility Mini-Lab In this lab we're going to measure the how easily a solute dissolves in the solvent to form a solution or a homogeneous mixture. In addition to exploring solubility, we will be experimenting with the melting point and boiling points of different substances. Materials 4 150 ML beakers of water, Mystery Substances A-D (located at bottom in teachers notes), 4 spoons, goggles Station 1 – Solubility & Saturation

Step 1: Take a tablespoon of sample A and drop It into beaker A. Step 2: Stir with spoon and record observations in data table. Step 3: Take a tablespoon of sample B and drop It into beaker B. Step 4: Stir with spoon and record observations in data table. Step 5: Take a tablespoon of sample C and drop It into beaker C. Step 6: Stir with spoon and record observations in data table. Step 7: Take a tablespoon of sample D and drop It into beaker D. Step 8: Stir with spoon and record observations in data table.

Mystery Substance: Is it soluble? (Did it What do you think the Why? dissolve?) mystery substance is? A B C D

HOT QUESTIONS:

1. Which substance was the most soluble? How do you know?

2. Are any of the soluble substances saturated? Why or why not.

3. What are some common uses for the soluble substance(s)?

4. Which substance is homogeneous? Why?

5. Which substance is heterogeneous? Why? Unit 2, Day 7

Station 2 – Melting Point Materials: 1 computer

Step 1: Go to this link on a student computer: http://www.sciencekids.co.nz/gamesactivities/meltingpoints.html

Step 2: Scroll down to the melting point game and click the blue arrows on the top of the activity to navigate.

Step 3: Complete the questions below as you go through the activity:

1. Object with the lowest melting point?

2. What was this objects melting point?

3. What happens to the chocolate when you heat it?

4. What is the melting point of the chocolate?

5. Describe how a liquid moves.

6. If you had a piece of chocolate two times bigger than the one in this activity would it have the same melting point? Why or why not.

7. Which object has the highest melting point?

8. Why does this object have the highest melting point?

9. Describe the molecules arrangement in a boiling substance. Unit 2, Day 7

Station 3 – Boiling Point – Phase Change Graph Matching Practice Graph Practice Worksheet *Directions: Match each graph to Substance: Melting Point Boiling Point each substance and write the letter 1. Water 0°C 100°C of the substance in the blank box 2. Chocolate 35°C 118°C next to the graph. After you match the substances based off of the 3. Popsicle 5°C 110°C information from the data table, be 4. Butter 50°C 120°C sure to answer the HOT Questions 5. Aluminum 660°C 2500°C for full credit. 6. Wax 60°C 340°C

A. Chocolate B. Butter C. Wax D. Aluminum E. Water F. Popsicle 1.

5. Unit 2, Day 7

HOT Questions

1. How can you tell the substances melting point by looking at the graph?

2. How can you tell the substances boiling point by looking at the graph?

3. Which substance had the highest boiling point? Why? Describe the molecule arrangement.

4. Which substance had the lowest boiling point? Why? Describe the molecule arrangement.

5. How does the melting point and boiling point of a substance help scientists identify and classify substances? Unit 2, Day 7

RIGHT SIDE: Melting Point, Boiling Point, and Solubility Notes

1. A physical property can be observed or ______; a characteristic. 2. Physical Properties help scientists ______matter. 3. Melting Point- The temperature at which a substance changes from a ______. 4. Boiling Point - The temperature at which a substance changes from a ______.

**Melting Point Activity

HOT Question: How could an objects melting point and boiling point help a scientist figure out what substance they have? Substance

5. Solubility - how easily a ______in the solvent to form a solution or a homogeneous mixture.

6. Saturated: when a solution holds the ______solute it can hold. -Cannot fit any more (any extra solute added would sink to the bottom)

EXIT SLIP

1. What is the difference between a solute and a solvent.

2. When a solution has as much solute as it can hold we call this ______.

3. When a solution has less solute than it can hold we call this ______.

4. Does the size of the sample affect its melting point or boiling point?

5. Why are melting point, boiling point, and solubility physical properties?

FCAT CHALLENGE QUESTION SC.8.P.8.4 – Boiling Point 1. Stephanie is given an unknown liquid to test in the laboratory. She thinks this liquid might be alcohol. Which physical property would be the most helpful for Stephanie to determine the identity of the liquid? A. Its color B. Its mass C. Its boiling point D. Its volume Unit 2, Day 7

Teacher Notes:

*Have students rotate between stations. It is not recommended to put more than five students in a group at once.

Suggested Station 1 Mystery Substances:

-Sugar -Pepper -Cornstarch -Coffee -Salt