Marine Science: Introduction to Density Lab
Materials:
Two 250 ml beakers, one 500 ml beaker
Electronic Scale
Glass stirring rod
Pickling Salt, Water Samples (both warm and cold), and food coloring (blue and yellow)
Two 250 ml beakers, one 500 ml beaker
Electronic Scale
Glass stirring rod
Pickling Salt, Water Samples (both warm and cold), and food coloring (blue and yellow)
Part One: What is the density?
Before we poured water in the beakers, we massed them, labeling one of the beakers Beaker 1 and the other Beaker 2. Beaker 1's mass was 112.9 g, and the Beaker 2's mass was 117g. After we finished massing them, we filled the beakers with 250 ml of water. Beaker 1 had the cold water, whereas Beaker 2 had the hot water. To Beaker 1, we put 20g of salt and 5 drops of food coloring and stirred it all together, making sure all the salt had dissolved. Beaker 2 was the same, except having no salt and yellow food coloring. After the stirring, we massed the beakers again. Beaker 1's mass was 387.9g, and Beaker 2's mass was 358.9g. Along with mass, we also had to find the volume and density for each beaker. Beaker 1 and 2 had the same volume, 250. However, Beaker 1's density was 1.5516, while Beaker 2's density was 1.4356.
Part Two: Try it out!
In this part, we poured Beaker 2's contents into the 500 ml beaker. We let the water settle before we added Beaker 1's contents. Very slowly, we poured the cold, salty water into the 500 ml beaker, and let it settle for 2-3 minutes.
Part 3: Observations
1. Explain what you observed in the 500 ml beaker. Include a diagram and vocabulary in your explanation.
As we slowly poured Beaker 1's contents into the 500 ml beaker, the water began to turn green.
2. Carefully tilt the beaker (do not spill any liquid) and hold it at a tilt for 15 seconds. Then gently (but quickly) place the beaker back on the table and observe what happens to the layers. Write a few sentences about what you observed.
We were unable to do this part of the activity. :(
As we slowly poured Beaker 1's contents into the 500 ml beaker, the water began to turn green.
2. Carefully tilt the beaker (do not spill any liquid) and hold it at a tilt for 15 seconds. Then gently (but quickly) place the beaker back on the table and observe what happens to the layers. Write a few sentences about what you observed.
We were unable to do this part of the activity. :(
Part 4: The Big Picture
1. I expect the third color to be green, as the two layers in the 500 ml beaker are yellow and blue.
2. I think the third layer would form in the middle.
3. The third layer's density would be in between Beaker 1's density and Beaker 2's density.
4. To make the third layer, you would use the glass stirring rod to stir in between the 2 layers.
2. I think the third layer would form in the middle.
3. The third layer's density would be in between Beaker 1's density and Beaker 2's density.
4. To make the third layer, you would use the glass stirring rod to stir in between the 2 layers.
Lesson Review
1. Thermal stratification of the oceans is when there are different layers of temperature in the oceans. It occurs because at the surface of the ocean, sunlight is making it through the ocean, giving it warmth to whatever lives near the surface. As you go deeper into the ocean, not only does it become darker, but colder too. This is due to sunlight not getting to that area in the ocean.
2. The name of this temperature stratification is vertical stratification
3. Thermal stratification of the ocean is important because some fish may survive in different depths of the ocean. Some may need sunlight, whereas others need a cold climate around them.
2. The name of this temperature stratification is vertical stratification
3. Thermal stratification of the ocean is important because some fish may survive in different depths of the ocean. Some may need sunlight, whereas others need a cold climate around them.