Water Structure/Properties Lab:
Virtual Lab Link
Note: If using Chrome, you may need to enable your browser to access the virtual lab. Click here for instructions on how to allow the flash to run on your browser.
Instructions:
Step 1: Click on the virtual lab link above. Drag the oxygen and hydrogen atoms to the Work Area. Arrange them to form a water molecule. Click Check. If the molecule is correct, you will see covalent bonds appear between the oxygen atom and each hydrogen atom. Notice the positive and negative charges of the molecule. Draw the water molecule you created along with its charges. Take photo and upload pic in performance task.
Step 2: Drag another water molecule to the one you just made. Position it so it will form a hydrogen bond with the first water molecule. Click Rotate if you need to turn the molecule. Click Check to see if the water molecules form a hydrogen bond. On a piece of paper, draw the two attached water molecules, take photo, and upload pic in performance task.
Step 3: Repeat the previous step until you have placed six attached water molecules. On a piece of paper, draw the six attached molecules. Take photo and upload pic in performance task.
Step 4: Click the Reference Tool to read about some properties of water. Drag each label to the appropriate place in the arrangement of water molecules. Then click Check. Keep repeating until you get the right placement of the tags. To see the arrangement of water molecules at different temperatures, click one of the Temperature buttons: -20°C, 30°C, or 110°C. On a piece of paper, draw the arrangement of water at -20C. Take photo and upload pic in performance task.
Step 5: On a piece of paper, draw the arrangement of water at 30C. Take photo and upload pic in performance task.
Step 6: Now see the molecules in motion at different temperatures. Click on -20C and click the Motion button. Observe the molecules motion at this temperature. Then repeat for 30C and 110C. Describe below what differences you see in the motion of water molecules as temperature increases.
Step 7: Why is the formation of hydrogen bonds between water molecules categorized as cohesion?
Step 8: Describe the surface tension in a group of bonded water molecules.
Step 9: Describe the arrangement of water molecules in a solid, liquid, and gas form. How does the movement of the molecules differ in each form?
Step 10: The density of a substance refers to how close together the molecules in that substance are packed. Describe the density of water in its three phases.
Step 11: A water molecule is slightly charged on both ends, which gives it its polarity. This is because oxygen is more electronegative than hydrogen. Check out the video (click here) of a stream of water being bent. Why do you think the water is bending when the ruler is present?
Step 12: Hydrogen bonds hold water molecules together, as seen in this picture (click here). Cohesion creates surface tension, which is why if you fill a spoon with water, drop by drop, the water volume will actually be bigger than the spoon's surface before the water falls off. Check out this video (click here) and describe why the paper clip doesn’t sink.
Step 13: Water is often called the universal solvent because it can dissolve more substances than any other liquid. Explain how the polarity of the water molecule makes it possible.
Virtual Lab Link
Note: If using Chrome, you may need to enable your browser to access the virtual lab. Click here for instructions on how to allow the flash to run on your browser.
Instructions:
Step 1: Click on the virtual lab link above. Drag the oxygen and hydrogen atoms to the Work Area. Arrange them to form a water molecule. Click Check. If the molecule is correct, you will see covalent bonds appear between the oxygen atom and each hydrogen atom. Notice the positive and negative charges of the molecule. Draw the water molecule you created along with its charges. Take photo and upload pic in performance task.
Step 2: Drag another water molecule to the one you just made. Position it so it will form a hydrogen bond with the first water molecule. Click Rotate if you need to turn the molecule. Click Check to see if the water molecules form a hydrogen bond. On a piece of paper, draw the two attached water molecules, take photo, and upload pic in performance task.
Step 3: Repeat the previous step until you have placed six attached water molecules. On a piece of paper, draw the six attached molecules. Take photo and upload pic in performance task.
Step 4: Click the Reference Tool to read about some properties of water. Drag each label to the appropriate place in the arrangement of water molecules. Then click Check. Keep repeating until you get the right placement of the tags. To see the arrangement of water molecules at different temperatures, click one of the Temperature buttons: -20°C, 30°C, or 110°C. On a piece of paper, draw the arrangement of water at -20C. Take photo and upload pic in performance task.
Step 5: On a piece of paper, draw the arrangement of water at 30C. Take photo and upload pic in performance task.
Step 6: Now see the molecules in motion at different temperatures. Click on -20C and click the Motion button. Observe the molecules motion at this temperature. Then repeat for 30C and 110C. Describe below what differences you see in the motion of water molecules as temperature increases.
Step 7: Why is the formation of hydrogen bonds between water molecules categorized as cohesion?
Step 8: Describe the surface tension in a group of bonded water molecules.
Step 9: Describe the arrangement of water molecules in a solid, liquid, and gas form. How does the movement of the molecules differ in each form?
Step 10: The density of a substance refers to how close together the molecules in that substance are packed. Describe the density of water in its three phases.
Step 11: A water molecule is slightly charged on both ends, which gives it its polarity. This is because oxygen is more electronegative than hydrogen. Check out the video (click here) of a stream of water being bent. Why do you think the water is bending when the ruler is present?
Step 12: Hydrogen bonds hold water molecules together, as seen in this picture (click here). Cohesion creates surface tension, which is why if you fill a spoon with water, drop by drop, the water volume will actually be bigger than the spoon's surface before the water falls off. Check out this video (click here) and describe why the paper clip doesn’t sink.
Step 13: Water is often called the universal solvent because it can dissolve more substances than any other liquid. Explain how the polarity of the water molecule makes it possible.